LFUS

Line plots across dimensions of each concept
Line plots across concepts
Tables

Plots across concepts

IncomeStatement

Expenses

Balance Sheet

Assets

Current Assets

NonCurrent Assets

PropertyPlantAndEquipmentNet

Liabilities

Current Liabilities

Noncurrent Liabilities

Stockholders Equity

CashFlow

NetCashProvidedByUsedInOperatingActivities

NetCashProvidedByUsedInInvestingActivities

OperatingLeaseLiability

LesseeOperatingLeaseLiabilityPaymentsDue

FiniteLivedIntangibleAssets

InventoryNet

AccountsReceivable

Tables

		2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
us-gaap:CommonStockValue	████▇▇▇▇▇▇▇▇▆▆▁▁▅▁▁	0.26	0.259	0.259	0.258	0.257	0.256	0.256	0.256	0.255	0.254	0.254	0.254	0.253	0.251	0.229	0.229	0.245	0.228	0.228	NA	NA	NA	0.224	NA	NA	NA	0.226	NA	NA	NA	0.225	NA	NA	NA	NA	0.22	NA	NA	NA	0.216	NA	NA	NA	0.218	NA	NA
us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding	█▁	24.9	24.892	NA	24.573	24.312	24.578	NA	24.684	24.983	25.009	NA	25.471	25.401	24.775	NA	22.953	23.023	22.989	NA	22.734	22.674	22.621	NA	22.693	22.835	22.781	NA	22.689	22.75	22.717	NA	22.625	22.499	22.366	NA	NA	22.162	22.074	21.929	NA	22.287	22.59	22.328	NA	22.344	22.397
us-gaap:WeightedAverageNumberOfSharesOutstandingBasic	█▁	24.592	24.532	NA	24.357	24.312	24.393	NA	24.482	24.74	24.717	NA	25.109	25.004	24.339	NA	22.713	22.822	22.748	NA	22.578	22.528	22.438	NA	22.581	22.691	22.6	NA	22.536	22.579	22.492	NA	22.428	22.296	22.095	NA	NA	21.923	21.778	21.608	NA	22.0	22.191	21.878	NA	21.968	22.019
us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	█▁	0.041216	1.5e-05	NA	NA	0.328624	0.153836	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	0.076845	0.060491	NA	NA	0.144031	0.113878	NA	NA	0.06452	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:EarningsPerShareBasic	█▆▆▆▁▄▄▅▅▅▄▆▅▅▁▅▆▅▄▄▄▃	3.34	2.35	2.41	2.27	-0.37	1.01	0.93	1.46	1.77	1.5	1.3100000000000005	2.13	1.69	1.48	-0.4800000000000004	1.88	2.13	1.71	1.1999999999999997	1.36	1.21	0.86	NA	0.5	1.26	0.88	0.86	1.33	1.09	1.13	1.05	1.2	1.19	0.67	NA	0.55	1.09	1.08	0.83	0.71	1.13	1.13	0.98	0.8999999999999999	1.06	0.91
us-gaap:EarningsPerShareDiluted	█▆▆▆▁▄▄▅▅▅▄▆▅▅▁▅▆▅▄▄▄▃	3.3	2.32	2.39	2.25	-0.37	1.0	0.92	1.44	1.75	1.48	1.2899999999999991	2.1	1.67	1.45	-0.4800000000000004	1.87	2.11	1.69	1.1899999999999995	1.35	1.2	0.85	NA	0.5	1.26	0.88	0.86	1.32	1.08	1.12	1.04	1.19	1.18	0.66	NA	0.53	1.08	1.07	0.81	0.7	1.12	1.11	0.96	0.8799999999999999	1.04	0.9

		2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03

		2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
TTM Greenblatt ROC _ _	█▇▆▆▁▅▄▅▅▆▅▇▆▄▅▆▆▅▄▄▄▄▄▂▄▄▃▄▄▄▄▄▄▄▃▃▄▄▃▃▄▄▄	96.257	76.481	65.014	64.558	-11.95	44.75	32.317	47.167	52.634	60.673	51.628	76.228	59.622	37.571	50.78	58.609	60.27	48.852	40.988	27.526	29.702	32.428	29.854	8.584	36.171	29.548	26.391	40.13	33.719	33.59	32.823	37.559	31.382	28.117	18.019	18.019	30.931	32.096	25.824	18.121	29.574	35.291	30.918	NA	NA	NA

		2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
us-gaap:ComprehensiveIncomeNetOfTax	█▆▇▇▁▂▄▃▄▅▄▅▄▄▂▅▅▅▂▄▃▄	87.549	52.842	75.058	72.337	-11.408	9.665	28.439	18.621	38.061	45.062	32.372	45.599	26.384	35.75	-1.144	42.569	44.485	44.518	7.818	25.888	11.899	29.975	NA	2.187	34.672	9.037	-8.569	13.209	33.743	19.492	30.328	36.707	17.956	7.662	NA	6.575	34.32	15.323	NA	5.281	7.301	28.943	NA	NA	NA	NA
us-gaap:CostOfGoodsAndServicesSold	█▇▆▅▄▄▄▅▅▅▅▆▇▆▃▃▃▂▂▂▃▁	326.092	303.328	260.511	253.39	208.238	222.384	225.056	231.025	256.071	250.272	247.944	259.597	290.196	268.19	178.225	184.238	180.747	171.791	170.181	166.572	174.046	132.243	NA	129.328	136.74	133.983	131.061	130.228	137.913	128.365	121.02	120.08	114.209	106.312	NA	99.387	104.052	106.291	99.716	93.667	105.516	106.621	102.457	88.69	96.212	98.125
us-gaap:CostOfRevenue	█▇▆▅▄▄▄▅▅▅▅▆▇▆▃▃▃▂▂▂▃▁	326.092	303.328	260.511	253.39	208.238	222.384	225.056	231.025	256.071	250.272	247.944	259.597	290.196	268.19	178.225	184.238	180.747	171.791	170.181	166.572	174.046	132.243	NA	129.328	136.74	133.983	131.061	130.228	137.913	128.365	121.02	120.08	114.209	106.312	NA	99.387	104.052	106.291	99.716	93.667	105.516	106.621	102.457	88.69	96.212	98.125
us-gaap:GrossProfit	█▆▅▅▃▄▄▄▅▆▆▇▇▅▄▅▅▄▄▄▃▂▂▂▂▂▂▂▂▂▂▂▁▁	197.396	160.466	138.083	138.176	99.099	123.712	113.467	130.946	141.808	155.228	154.337	179.594	168.987	149.623	126.624	133.651	132.608	113.65	114.337	113.759	97.866	87.155	82.706	86.182	85.281	76.33	75.559	87.38	82.995	78.494	77.109	80.96	73.557	64.606	NA	59.407	68.636	69.562	60.862	53.526	68.471	69.994	64.703	53.956	67.253	59.383
us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	█▇▆▆▁▄▃▄▅▅▄▆▅▅▅▅▅▅▄▄▄▃	95.197	72.708	68.913	67.426	-10.585	35.499	24.474	41.404	53.567	46.439	39.767	68.212	52.318	44.646	43.729	55.523	57.357	47.428	31.75	30.433	34.014	27.077	NA	12.641	37.717	26.406	25.072	41.2	31.562	33.812	34.342	36.524	35.397	17.972	11.327	11.327	30.993	32.432	25.3	18.655	31.057	34.781	30.608	NA	NA	NA
us-gaap:IncomeTaxExpenseBenefit	▃▃▂▃▁▃▁▂▂▂▂▃▂▂█▃▂▂▂▁▂▂	13.102	14.995	9.936	12.07	-1.594	10.855	1.82	5.757	9.775	9.45	7.102	14.666	9.992	8.617	54.548	12.715	8.719	8.537	4.505	-0.369	6.862	7.788	NA	1.317	9.033	6.411	5.561	11.26	6.984	8.423	13.99	9.534	8.749	3.178	NA	1.486	6.995	8.828	7.411	3.417	6.118	9.512	9.03	4.611	10.486	8.282
us-gaap:InterestExpense	▆▆▆▇█▇▇██████▇▄▄▄▃▂▃▁▂	4.626	4.673	4.816	4.988	5.855	5.418	5.432	5.559	5.589	5.686	5.589	5.775	5.782	5.423	3.512	3.467	3.281	3.12	2.342	2.571	1.67	2.045	NA	0.922	0.948	1.151	1.167	1.292	1.228	1.216	0.958	0.939	0.644	0.376	0.403	0.403	0.454	0.421	0.423	0.42	0.414	0.521	0.336	0.341	0.313	0.356
us-gaap:InterestExpenseDebt	▁█	2.5	6.235	NA	6.4	3.4	7.4	NA	6.4	3.5	8.0	NA	8.1	3.7	4.0	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:OperatingExpenses	▇▅▃▃█▄▄▅▅▆▇▇██▄▃▃▂▃▅▃▁	101.139	83.985	75.171	73.618	111.049	78.962	81.15	83.779	89.174	94.555	102.709	103.366	109.365	112.052	75.844	75.042	72.338	64.798	73.349	86.233	68.164	54.727	NA	77.598	49.11	46.782	49.168	47.25	49.276	44.904	44.286	43.401	42.175	36.489	NA	41.388	37.705	37.466	35.038	35.405	38.897	34.703	33.785	29.64	33.145	31.876
us-gaap:OperatingIncomeLoss	█▇▆▆▁▅▄▅▅▆▅▇▆▄▅▆▆▅▄▄▄▄▄▂▄▄▃▄▄▄▄▄▄▄▃▃▄▄▃▃▄▄▄▃▄▄	96.257	76.481	65.014	64.558	-11.95	44.75	32.317	47.167	52.634	60.673	51.628	76.228	59.622	37.571	50.78	58.609	60.27	48.852	40.988	27.526	29.702	32.428	29.854	8.584	36.171	29.548	26.391	40.13	33.719	33.59	32.823	37.559	31.382	28.117	18.019	18.019	30.931	32.096	25.824	18.121	29.574	35.291	30.918	24.316	34.108	27.507
us-gaap:OtherComprehensiveIncomeLossNetOfTax		NA	NA	16.081	16.981	-2.417	-14.979	5.785	-17.026	-5.731	8.073	-0.293	-7.947	-15.942	-0.279	9.675	-0.239	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:OtherComprehensiveIncomeLossNetOfTax us-gaap:StatementEquityComponents us-gaap:AccumulatedDefinedBenefitPlansAdjustment		NA	NA	-6.38	0.563	-10.839	0.561	-8.336	0.137	0.161	-0.049	0.229	-0.115	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:OtherComprehensiveIncomeLossNetOfTax us-gaap:StatementEquityComponents us-gaap:AccumulatedOtherComprehensiveIncome		NA	NA	NA	16.981	-2.417	-14.979	NA	-17.026	-5.731	8.073	NA	-7.947	-15.942	-0.279	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:OtherComprehensiveIncomeLossNetOfTax us-gaap:StatementEquityComponents us-gaap:AccumulatedTranslationAdjustment		NA	NA	22.461	16.418	8.422	-15.54	14.121	-17.163	-5.892	8.122	-0.522	-7.832	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:OtherIncome us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome,us-gaap:StatementEquityComponents us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome,us-gaap:AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceIncludingPortionAttributableToNoncontrollingInterest	█▁	0.509	0.504	NA	NA	0.429	0.345	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:OtherNonoperatingIncomeExpense	▅█▆▄▄▃▂▆▅▁▃▃▄▅▄▄▃▄▄▄▃▄	1.89	7.737	3.44	1.682	1.21	-1.249	-2.823	4.764	2.947	-4.305	-0.763	-1.259	1.678	1.943	0.32	1.013	-0.19	0.139	0.69	0.778	-0.255	0.517	NA	1.43	1.202	1.126	1.751	2.261	1.446	1.186	1.103	1.38	4.659	0.909	4.224	1.045	0.516	0.757	-0.101	0.954	1.897	0.011	0.026	0.214	0.029	1.409
us-gaap:ProfitLoss	█▆▆▆▁▄▄▅▅▅▄▆▅▅▁▅▅▅▄▄▄▃▄▃▄▃▃▄▄▄▄▄▄▃	82.095	57.713	58.977	55.356	-8.991	24.644	22.654	35.647	43.792	36.989	32.665	53.546	42.326	36.029	-10.819	42.808	48.638	38.891	27.245	30.802	27.152	19.289	22.463	11.324	28.684	19.995	19.511	29.94	24.578	25.389	23.658	26.99	26.648	14.794	NA	9.841	23.998	23.604	17.889	15.238	24.939	25.269	21.578	19.578	23.338	20.278
us-gaap:ResearchAndDevelopmentExpense	▅▄▂▃▃▄▆▇▇▇▇▇██▃▃▃▃▂▂▃▁	16.394	14.739	11.494	13.049	13.4	14.595	17.944	19.728	21.458	21.409	21.559	20.454	22.748	22.54	13.617	11.991	12.729	12.151	11.314	10.403	11.916	8.565	NA	7.479	7.361	7.384	8.289	7.449	7.81	7.574	6.69	6.217	5.793	5.715	NA	5.678	5.505	4.887	5.161	4.685	5.297	4.662	4.795	4.904	4.345	4.403
us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax	█▇▆▆▄▅▅▅▆▆▆▆▇▆▄▄▄▄▄▄▃▂▂▂▂▂▂▂▂▂▂▂▂▂▁▁▂▂▁▁▂▂▁▁▁▁	523.488	463.794	400.696	391.566	307.337	346.096	338.523	361.971	397.879	405.5	402.281	439.191	459.183	417.813	304.849	317.889	313.355	285.441	284.518	280.331	271.912	219.398	220.02	215.51	222.021	210.313	206.62	217.608	220.908	206.859	198.129	201.04	187.766	170.918	158.794	158.794	172.688	175.853	160.578	147.193	173.987	176.615	167.16	142.646	163.465	157.508
us-gaap:SellingGeneralAndAdministrativeExpense	▇▄▂▃▃▃▃▃▄▅▆▆▇█▄▄▃▂▄▄▃▁	73.315	58.288	45.675	50.465	53.981	54.386	53.248	54.224	57.666	62.955	67.461	69.782	73.244	77.514	55.934	56.759	53.438	46.703	56.082	56.589	51.092	42.366	NA	37.002	38.772	36.345	37.829	36.647	38.328	34.171	34.566	34.437	34.452	29.202	NA	34.078	30.601	31.189	28.409	28.889	32.015	28.441	27.395	23.463	27.553	26.208

		2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03

		2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
us-gaap:Assets	██▇▇▇▇▇▇▇▇▇▇▇▇▄▄▄▃▃▃▃▃▂▂▂▂▂▂▂▂▂▂▂▁	2927.498	2786.87	2747.593	2654.37	2611.058	2612.629	2559.898	2551.361	2621.585	2625.018	2614.306	2663.486	2587.994	2627.51	1740.102	1702.192	1622.191	1544.046	1491.194	1458.103	1341.798	1403.11	1064.981	1091.877	1099.291	1059.015	1070.826	1133.815	1128.899	1095.666	1024.373	1006.931	959.815	787.814	NA	777.728	763.347	725.37	716.584	678.424	687.06	696.489	NA	621.129	NA	NA
us-gaap:LiabilitiesAndStockholdersEquity	██▇▇▇▇▇▇▇▇▇▇▇▇▄▄▄▃▃▃▃▃▂▂▂▂▂▂▂▂▂▂▂▁	2927.498	2786.87	2747.593	2654.37	2611.058	2612.629	2559.898	2551.361	2621.585	2625.018	2614.306	2663.486	2587.994	2627.51	1740.102	1702.192	1622.191	1544.046	1491.194	1458.103	1341.798	1403.11	1064.981	1091.877	1099.291	1059.015	1070.826	1133.815	1128.899	1095.666	1024.373	1006.931	959.815	787.814	NA	777.728	763.347	725.37	716.584	678.424	687.06	696.489	NA	621.129	NA	NA
us-gaap:StockholdersEquity	█▇▇▆▆▆▆▆▆▆▆▆▆▆▂▂▂▁▁	1742.089	1660.606	1608.642	1529.431	1462.303	1476.817	1495.883	1472.081	1509.811	1505.257	1478.211	1519.266	1469.89	1441.837	927.419	933.107	895.289	855.618	814.788	NA	NA	NA	744.055	NA	NA	NA	727.522	NA	NA	NA	686.773	NA	NA	NA	NA	587.415	NA	NA	NA	500.96	NA	NA	NA	452.517	NA	NA

		2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
us-gaap:AssetsCurrent	█▇▇▇▆▆▅▅▆▆▆▆▅▅▄▃▃▂▂▂▁▂▂▂▂▂▂▂▂▂▂▂▁▁	1318.918	1192.412	1217.309	1148.934	1119.165	1092.483	1004.394	1007.592	1039.549	1030.145	1032.517	1052.634	958.201	973.062	792.34	759.364	704.852	634.225	612.081	555.169	519.877	605.788	583.435	613.774	603.122	566.862	571.505	645.634	629.4	597.521	565.599	557.272	516.06	465.886	NA	445.465	429.742	403.096	416.698	378.382	388.243	393.715	NA	318.956	NA	NA
us-gaap:CashAndCashEquivalentsAtCarryingValue	▇▆█▇█▇▆▅▅▅▅▅▄▄▄▄▃▂▂▁▁▂▃▃▃▃▃▄▃▃▃▃▂▂	616.33	572.771	687.525	641.89	651.867	620.575	531.139	476.057	474.781	476.614	489.733	498.215	408.147	412.458	429.676	372.828	321.893	277.979	275.124	194.494	179.461	272.864	328.786	336.64	311.915	293.631	297.571	378.276	346.406	319.806	305.192	292.936	257.672	246.895	NA	235.404	207.398	168.818	178.692	164.016	163.424	163.924	131.533	109.72	118.927	87.682
us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	▆▄█▆▇▆▃▁▁▁▁▂	621.854	577.297	687.525	641.89	651.867	620.575	531.139	476.057	474.781	476.614	489.733	498.215	NA	NA	429.676	NA	NA	NA	275.124	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:ShortTermInvestments	▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▁▅▅▅▅▅▅▅▅▅▁███	0.018	0.053	0.054	0.052	0.044	0.043	0.044	0.033	0.034	0.033	0.034	0.035	0.034	0.037	0.035	0.035	0.034	0.032	3.69	3.961	3.92	4.354	4.179	3.958	3.954	3.869	4.302	0.038	6.849	6.943	6.886	NA	NA	NA	NA	NA	NA	5.475	19.022	13.997	NA	NA	NA	NA	NA	NA
us-gaap:AccountsReceivableNetCurrent	█▇▅▅▄▄▄▅▆▅▅▆▆▆▄▄▄▅▄▄▄▄▂▂▃▂▂▂▂▂▂▂▂▁	313.332	276.687	232.76	231.93	185.806	207.912	202.309	226.352	245.723	237.878	232.892	251.644	260.444	244.905	182.699	197.539	199.027	212.586	198.095	205.211	197.543	181.384	142.882	145.655	151.283	136.133	135.356	134.706	144.869	136.077	127.887	129.122	131.122	107.044	NA	100.559	109.179	115.874	106.985	92.088	110.689	118.31	NA	97.753	NA	NA
us-gaap:InventoryNet	█▇▆▆▆▅▆▆▆▆▆▆▆▆▃▃▂▂▂▂▂▃▂▂▂▂▂▂▂▂▂▂▁▁	325.774	295.057	258.002	243.832	248.02	227.282	237.507	240.059	254.305	261.659	258.228	247.255	239.201	263.969	140.789	136.505	125.24	118.311	114.063	121.616	124.7	133.162	98.629	99.203	97.735	96.159	97.391	99.822	96.674	99.121	92.591	91.978	83.47	71.372	NA	75.58	81.073	80.829	77.729	75.575	82.412	79.865	NA	80.182	NA	NA
us-gaap:InventoryFinishedGoods	█▆▃▂▂▁▃	142.777	130.138	114.641	105.425	106.904	100.415	110.388	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	49.616	50.888	46.787	35.328	41.771	37.491	NA	42.023	41.24	38.741	NA	37.952	NA	NA	NA	NA	NA	NA
us-gaap:InventoryRawMaterialsAndSupplies		NA	NA	85.394	NA	NA	NA	76.732	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:PrepaidExpenseAndOtherAssetsCurrent	█▅▄▄▄▄▄██▇▆▆▆▆▅▆▇▂▁▂▂▂▁▂▂▂▂▂▂▂▂▂▂▂	59.503	43.698	35.939	30.012	31.899	32.418	28.564	62.361	63.332	53.203	49.291	48.683	45.727	47.794	37.452	45.799	51.938	13.044	9.438	15.543	14.253	14.024	8.959	14.179	15.357	13.964	13.904	16.57	18.492	19.665	17.08	17.771	18.819	15.857	NA	16.532	13.982	NA	NA	14.219	NA	NA	NA	NA	NA	NA

		2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
us-gaap:NoncurrentAssets	████▇▇█▇▇███▇▇▄▄▄▃▃▃▃▄▁▁▁▁▁	352.826	344.914	344.178	339.87	334.677	334.829	344.617	329.792	338.5	342.334	339.894	343.883	338.755	337.205	250.577	244.874	232.539	223.942	217.175	223.853	224.51	229.865	162.568	162.765	166.379	160.872	158.64	NA	NA	NA	150.173	146.1	141.133	120.3	NA	303.315	301.882	289.456	NA	279.164	NA	NA	NA	284.662	NA	NA
us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType us-gaap:Building	█▇▆▆▅▁▂▁▂▄▄	128.528	124.192	123.497	122.914	118.409	105.067	108.501	106.062	106.962	114.506	114.636	NA	NA	NA	86.599	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType us-gaap:Equipment	█▇▆▅▄▄▄▂▃▂▁	706.115	687.563	678.22	656.681	635.661	633.899	631.273	605.965	612.58	599.254	583.043	NA	NA	NA	505.838	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType us-gaap:Land	▁▃▃▄▃▃▆▆▇██	21.795	22.711	22.851	23.438	23.095	22.781	24.758	24.699	24.962	25.607	25.63	NA	NA	NA	9.547	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	██▇▇▆▆▆▅▅▅▅▄▄▄▄▄▃▃▃▃▃▃▂▂▂▂▂▂▂▂▁▂▁▁	503.612	489.552	480.39	463.163	442.488	426.918	419.915	406.934	406.004	397.033	383.415	374.575	367.73	366.118	351.407	344.288	333.593	322.213	312.188	309.062	324.799	305.413	296.48	290.663	291.735	287.212	281.845	278.927	277.791	270.032	268.383	275.906	268.358	251.162	NA	244.845	245.407	238.487	227.704	220.255	215.307	212.06	NA	205.001	NA	NA
us-gaap:AmortizationOfIntangibleAssets	▆▆▅▅▅▅▅▅▅▆███▇▃▃▃▃▃▁▂▁	10.641	10.521	10.127	10.104	9.827	9.981	9.958	9.827	10.05	10.2	13.699	13.1	13.373	11.998	6.293	6.292	6.171	5.944	5.953	4.432	5.156	3.796	NA	2.923	2.977	3.053	3.05	3.154	3.138	3.159	3.03	2.747	1.93	1.572	NA	1.632	1.599	1.39	1.468	1.831	1.585	1.6	1.595	1.273	1.247	1.265
us-gaap:PropertyPlantAndEquipmentNet	████▇▇█▇██████▅▅▄▄▄▄▄▄▂▂▂▂▂▂▂▂▂▂▂▁	352.826	344.914	344.178	339.87	334.677	334.829	344.617	329.792	338.5	342.334	339.894	343.883	338.755	337.205	250.577	244.874	232.539	223.942	217.175	223.853	224.51	230.233	162.568	162.765	166.379	160.872	158.64	157.26	158.659	158.517	150.173	146.1	141.133	120.3	NA	120.911	118.03	116.074	116.659	118.884	120.27	127.299	NA	130.147	NA	NA
us-gaap:LongTermInvestments	██▆▅▄▄▄▅▅▄▅▅▆▆▁	39.255	37.285	30.547	26.066	23.678	21.248	24.099	26.662	25.456	24.64	25.405	29.084	31.326	31.128	10.993	NA	NA	NA	13.933	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:Goodwill	████▇█████████▄▄▄▄▄▄▃▃▂▂▂▂▂▂▂▂▂▂▂▁	851.07	845.586	816.812	799.791	787.601	812.763	820.589	813.653	826.408	825.467	826.715	830.354	832.227	840.574	453.414	451.131	432.134	428.343	403.544	409.527	363.341	312.064	189.767	190.016	192.947	190.804	196.256	198.702	201.769	199.415	186.464	186.667	185.035	131.85	NA	133.592	133.356	131.713	116.693	115.697	119.582	113.005	NA	112.687	NA	NA
us-gaap:IntangibleAssetsNetExcludingGoodwill	▅▅▄▄▄▅▅▅▆▆▆▇▇█▁	307.771	317.294	291.887	296.159	301.661	308.393	321.247	326.417	341.174	350.421	361.474	377.151	390.052	405.406	203.85	NA	NA	NA	213.027	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:FiniteLivedIntangibleAssetsNet	▅▅▄▄▄▅▅▅▆▆▆▇▇█▁	307.771	317.294	291.887	296.159	301.661	308.393	321.247	326.417	341.174	350.421	361.474	377.151	390.052	405.406	203.85	NA	NA	NA	213.026	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:OperatingLeaseRightOfUseAsset	█▆▅▆▆▆▆▆▇▇▁	28.465	19.56	17.615	18.811	19.621	20.611	21.918	21.598	23.28	24.725	0.0	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:OtherAssetsNoncurrent	▆▆▅▅▅▄▄▅▅▆▆▆██▅▃▃▃▃▄▅▇▄▅▆▇▇▂▂▂▂▂▂▁	19.356	19.965	18.021	17.566	17.1	14.694	14.965	18.162	18.018	18.825	20.971	21.401	27.113	28.096	17.07	8.913	10.885	10.255	10.849	12.857	18.46	23.001	14.058	16.216	19.456	22.985	23.303	6.75	7.065	7.229	6.402	4.893	4.162	1.878	NA	1.865	2.186	2.136	1.852	1.82	2.368	2.797	NA	2.58	NA	NA
us-gaap:EquitySecuritiesFvNi	█▇▅▃▂▁▂▂▁▁▁▂▃▃▁	27.532	25.83	19.186	15.042	12.899	10.529	12.969	12.648	11.161	10.551	10.312	12.204	15.328	14.754	10.993	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA

		2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
us-gaap:AccountsPayableCurrent	█▇▆▅▄▄▄▄▅▅▅▅▅▅▄▄▄▃▃▃▃▃▂▂▂▂▂▁▁▁▁▁▁▁	205.138	179.723	145.984	120.938	113.767	106.796	117.32	107.211	123.058	129.092	126.323	129.871	127.29	120.817	101.844	103.849	100.826	88.36	90.712	81.382	78.197	73.619	51.658	53.308	53.919	47.385	50.793	37.062	36.793	37.341	33.872	38.937	36.641	29.582	NA	27.226	27.389	28.477	28.65	19.934	26.215	30.412	NA	24.079	NA	NA
us-gaap:AccruedIncomeTaxesCurrent	▅▅▄▃▂▄▃▄▅▅▄█▄▃▃▃▂▂▂▂▁▂▂▁▂▂▂▃▁▁▁▂▁▂	25.109	23.468	19.186	15.231	10.034	17.907	14.122	16.989	21.657	23.244	20.547	36.746	19.376	15.938	16.285	16.281	9.522	8.827	8.846	8.622	6.682	9.929	10.621	6.738	8.547	9.893	9.045	15.059	6.422	7.357	5.931	10.154	6.226	8.196	NA	11.559	12.991	11.901	13.214	10.591	19.942	18.273	NA	14.997	NA	NA
us-gaap:AccruedLiabilitiesCurrent	▇▆▆▆▅▄▅▇▇▆█▅▄▅▃▃▃▃▂▃▄▃▂▂▂▁▁▁▁▁▁▁▁▁	126.445	98.354	110.478	98.437	85.356	73.512	84.12	114.549	111.696	107.214	138.405	74.084	66.341	74.925	48.994	52.786	50.536	47.849	36.138	48.713	55.716	40.35	24.145	20.641	19.668	12.122	13.059	13.342	13.972	13.267	13.087	11.643	11.295	9.703	NA	11.062	10.316	8.294	8.772	8.861	9.191	9.366	NA	10.307	NA	NA
us-gaap:ContractWithCustomerLiabilityCurrent	▁▁█	0.79	0.794	3.858	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:LiabilitiesCurrent	█▆▅▃▃▃▃▄▄▅▅▆▄▄▃▃▂▂▂▂▂▃▃▃▂▂▃▅▅▄▃▃▃▁	381.692	326.545	275.648	234.606	209.157	208.215	225.562	248.749	266.411	269.55	295.275	303.886	267.163	264.378	224.794	226.156	202.192	177.172	187.541	187.904	178.788	232.683	209.833	232.087	203.686	190.072	204.466	280.312	283.67	268.199	208.738	221.265	211.797	155.631	NA	155.42	160.52	156.453	164.413	149.277	171.513	148.626	NA	109.848	NA	NA
us-gaap:LongTermDebtCurrent	▄▄	25.0	25.0	NA	NA	0.0	10.0	10.0	10.0	10.0	10.0	10.0	10.076	10.06	10.111	6.25	9.375	7.813	6.25	6.25	6.25	6.25	6.25	87.0	117.5	82.25	87.0	88.5	186.5	204.0	193.0	126.0	133.5	138.0	94.0	NA	84.0	88.534	85.242	96.5	85.0	93.0	70.0	NA	33.0	NA	NA
us-gaap:OperatingLeaseLiabilityCurrent	█▇▆▆▆▇▇▆▇▇▁	8.853	7.177	6.811	6.866	6.846	7.073	7.259	6.926	7.349	7.447	0.0	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:OtherAccruedLiabilitiesCurrent	▆▆▄▄▂▁▁▂▂▃█	32.057	32.398	29.251	28.099	23.276	22.146	22.424	23.436	24.118	25.883	36.7	NA	NA	NA	27.819	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	1.843	1.871	2.142	NA	3.279	NA	NA

		2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
us-gaap:LongTermDebt	▇▇▇▇██▇▇▇▇▇▇▇█▅▅▅▄▄▄▃▃▁▁▁▁▁▂▂▂▂▂▂	651.917	648.865	687.034	725.507	776.205	774.195	679.158	678.16	686.94	686.51	694.73	700.713	697.598	753.548	495.611	501.647	481.692	470.523	454.142	440.456	367.982	377.363	171.474	209.017	179.243	189.969	195.158	276.5	295.25	285.5	219.75	228.5	233.0	NA	NA	-84.0	NA	NA	NA	-85.0	NA	NA	NA	NA	NA	NA
us-gaap:LongTermDebtNoncurrent	▆▆▇▇██▇▇▇▇▇▇▇█▅▅▅▅▅▅▄▄▁▁▁▁▁▁▁▁▁	626.917	623.865	687.034	725.507	776.205	764.195	669.158	668.16	676.94	676.51	684.73	690.637	687.538	743.437	489.361	492.272	473.879	464.273	447.892	434.206	361.732	371.113	84.474	91.517	96.993	102.969	106.658	90.0	91.25	92.5	93.75	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:DeferredIncomeTaxLiabilitiesNet	▂▆▅▁▁▄▄▇█	47.518	51.229	50.134	46.584	46.562	49.698	49.763	51.776	53.039	NA	44.523	NA	NA	NA	5.211	7.719	8.826	8.539	7.066	7.345	NA	NA	8.014	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent	███▇▇▆▇▅▆▆▆▆▆▆▄▄▃▃▃▂▂▂▂▂▂▂▂▁▁	43.176	42.894	45.802	40.279	39.653	35.904	38.198	28.725	30.666	31.548	31.874	32.901	33.21	35.817	18.742	16.571	15.975	13.926	13.398	6.235	7.498	7.481	5.653	5.025	5.247	5.073	5.147	0.225	0.182	NA	8.528	14.928	14.925	17.692	NA	22.338	10.691	10.471	10.544	15.292	5.356	5.482	NA	5.564	NA	NA
us-gaap:MinorityInterest	▂▂▂▂▂▂▂▂▂▂▂▁▁▅▅▅███	0.131	0.131	0.131	0.131	0.131	0.131	0.131	0.131	0.131	0.131	0.131	0.13	0.13	0.137	0.137	0.137	0.143	0.143	0.143	NA	NA	NA	0.143	NA	NA	NA	0.143	NA	NA	NA	0.143	NA	NA	NA	NA	0.143	NA	NA	NA	0.143	NA	NA	NA	0.143	NA	NA
us-gaap:OtherLiabilitiesNoncurrent	▇▇▇▆▆▆▆▆▆▇▇▇▇█▆▃▂▂▂▂▁▁▁▁▁▁▁▁▁▂▁▁▁▁	66.734	67.41	67.252	63.639	61.892	61.709	64.037	64.502	65.944	69.414	72.232	67.404	76.067	81.379	62.58	26.23	25.887	24.375	20.366	19.037	12.576	12.329	12.809	10.943	14.9	15.44	15.814	14.558	14.922	16.907	14.856	15.331	15.406	13.82	NA	12.412	11.608	11.775	12.27	12.752	13.698	14.267	NA	11.571	NA	NA
us-gaap:OperatingLeaseLiabilityNoncurrent	█▆▆▆▆▇▇▇██▁	19.241	14.19	12.95	14.193	15.155	15.96	17.166	17.237	18.643	19.95	0.0	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo		NA	NA	6.162	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree		NA	NA	3.952	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour		NA	NA	3.35	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive		NA	NA	0.262	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive		NA	NA	0.302	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA

		2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
us-gaap:StockholdersEquity	█▇▇▆▆▆▆▆▆▆▆▆▆▆▂▂▂▁▁	1742.089	1660.606	1608.642	1529.431	1462.303	1476.817	1495.883	1472.081	1509.811	1505.257	1478.211	1519.266	1469.89	1441.837	927.419	933.107	895.289	855.618	814.788	NA	NA	NA	744.055	NA	NA	NA	727.522	NA	NA	NA	686.773	NA	NA	NA	NA	587.415	NA	NA	NA	500.96	NA	NA	NA	452.517	NA	NA
us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	██▇▇▆▆▆▆▇▇▆▇▆▆▃▃▃▃▂▂▂▂▂▂▂▂▂▂▂▂▂▁▁▁	1742.22	1660.737	1608.773	1529.562	1462.434	1476.948	1496.014	1472.212	1509.942	1505.388	1478.342	1519.396	1470.02	1441.974	927.556	933.244	895.432	855.761	814.931	803.376	774.857	773.313	744.198	733.74	767.292	735.261	727.665	737.899	727.493	706.367	686.916	660.407	622.687	600.671	NA	587.558	580.528	546.671	529.357	501.103	496.446	528.062	NA	452.66	NA	NA
us-gaap:CommonStockValue	████▇▇▇▇▇▇▇▇▆▆▁▁▅▁▁	0.26	0.259	0.259	0.258	0.257	0.256	0.256	0.256	0.255	0.254	0.254	0.254	0.253	0.251	0.229	0.229	0.245	0.228	0.228	NA	NA	NA	0.224	NA	NA	NA	0.226	NA	NA	NA	0.225	NA	NA	NA	NA	0.22	NA	NA	NA	0.216	NA	NA	NA	0.218	NA	NA
us-gaap:AdditionalPaidInCapital	█████▇▇▇▇▇▇▇▇▇▁▁▁▁▁	930.106	918.762	907.858	891.924	885.306	874.36	867.996	860.871	855.192	842.086	835.828	830.612	815.826	800.614	310.012	306.118	302.238	295.372	291.258	NA	NA	NA	259.553	NA	NA	NA	243.844	NA	NA	NA	223.425	NA	NA	NA	NA	195.803	NA	NA	NA	174.375	NA	NA	NA	NA	NA	NA
us-gaap:RetainedEarningsAccumulatedDeficit	█▇▆▆▅▅▅▅▅▄▄▄▃▃▂▂▂▁▁	1150.26	1079.979	1034.048	986.81	943.151	963.82	950.901	939.946	916.014	882.871	856.507	834.577	791.831	758.766	722.14	741.363	706.959	665.812	634.391	NA	NA	NA	562.717	NA	NA	NA	523.302	NA	NA	NA	445.059	NA	NA	NA	NA	435.34	NA	NA	NA	376.572	NA	NA	NA	304.056	NA	NA
us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax	▃▂▃▂▁▁▂▂▂▃▂▂▃▃▄▃▃▄▃▄▅▅▅▅▆▅▆▇████▇▇	-90.574	-96.028	-91.157	-107.238	-124.219	-121.802	-106.823	-112.608	-95.582	-89.851	-97.924	-97.631	-89.684	-73.742	-63.668	-73.343	-73.104	-68.952	-74.579	-55.152	-50.238	-34.985	-45.671	-35.233	-26.096	-32.084	-21.126	6.954	23.685	14.52	20.417	13.747	4.03	12.722	NA	16.548	19.814	9.492	NA	8.631	NA	NA	NA	21.241	NA	NA
us-gaap:TreasuryStockValue	██████▇▇▅▄▄▁▁▁▁▁▁▁▁	247.963	242.366	242.366	242.323	242.192	239.817	216.447	216.384	166.068	130.103	116.454	48.546	48.336	44.052	41.294	41.26	41.049	36.842	36.51	NA	NA	NA	32.766	NA	NA	NA	18.724	NA	NA	NA	2.353	NA	NA	NA	NA	60.496	NA	NA	NA	58.834	NA	NA	NA	23.546	NA	NA
us-gaap:MinorityInterest	▂▂▂▂▂▂▂▂▂▂▂▁▁▅▅▅███	0.131	0.131	0.131	0.131	0.131	0.131	0.131	0.131	0.131	0.131	0.131	0.13	0.13	0.137	0.137	0.137	0.143	0.143	0.143	NA	NA	NA	0.143	NA	NA	NA	0.143	NA	NA	NA	0.143	NA	NA	NA	NA	0.143	NA	NA	NA	0.143	NA	NA	NA	0.143	NA	NA
us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	█▁	8.843	3.395	NA	3.692	7.887	2.965	NA	3.488	8.284	3.966	4.278	7.27	7.169	8.714	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA

		2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
us-gaap:NetCashProvidedByUsedInOperatingActivities	▆▄▇▅▄▃▆▆▄▂▆█▅▅▆▆▅▂▆▅▂▁	76.18	50.166	93.775	62.97	56.007	45.279	84.465	80.771	49.173	30.919	79.712	111.201	71.647	69.268	87.85	87.747	70.63	22.943	80.118	64.739	25.784	9.492	NA	51.619	38.734	23.23	49.31	61.318	31.004	11.509	31.556	46.806	22.96	16.045	NA	40.119	43.474	24.713	7.864	36.797	37.884	NA	13.717	29.138	48.795	NA
us-gaap:NetCashProvidedByUsedInInvestingActivities	█▅███████████▁█▇███▅▆▂	-17.92	-122.02	-10.045	-11.998	-12.854	-16.536	-23.497	-13.148	-5.568	-14.244	-13.685	-17.829	-26.357	-324.377	-16.936	-43.084	-14.019	-22.098	-12.762	-124.278	-100.984	-273.219	NA	-6.227	-10.548	-12.273	-38.645	0.515	-7.455	-58.408	-6.945	-10.781	-153.945	-13.922	NA	-8.563	-11.087	-24.203	-7.839	-22.759	-15.628	NA	-4.447	-54.736	-8.551	NA
us-gaap:NetCashProvidedByUsedInFinancingActivities	▂▂▂▁▂▄▂▁▂▂▁▃▂█▂▃▂▃▃▄▂▇	-14.91	-34.273	-49.432	-68.902	-15.278	65.804	-10.811	-59.841	-44.291	-31.333	-73.362	-0.948	-44.101	240.308	-18.19	3.588	-13.017	2.938	21.815	73.594	-14.946	203.733	NA	-7.543	-11.164	-8.445	-84.716	-23.056	-0.912	65.431	-10.768	-5.222	146.882	11.34	NA	-5.702	1.814	-7.666	12.304	-10.231	-16.858	NA	8.689	17.594	-15.194	NA
us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	▆▁▆▅▆█▇▅▅▄▅	44.557	-110.228	45.635	-9.977	31.292	89.436	55.082	1.276	-1.833	-13.119	-8.482	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA

		2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
us-gaap:DeferredIncomeTaxExpenseBenefit	▄▄▃▄▅▄▄▄▄▄▆▁▅▄█▄▅▄	-2.55	0.378	-4.781	-0.945	1.896	0.616	-0.944	0.429	-0.56	-0.072	6.3	-13.413	1.592	0.842	15.2	0.349	0.898	0.616	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:DepreciationDepletionAndAmortization	▇▇▇▇▇▇▆▆▆▆███▆▃▃▃▃▃▂▂▁	24.215	24.198	24.313	24.329	23.734	23.802	23.447	23.088	22.689	23.279	27.133	26.258	26.19	23.612	16.377	15.946	15.617	15.072	14.912	13.117	14.081	11.026	NA	10.315	10.373	10.418	10.688	10.431	10.59	10.166	8.628	9.601	8.447	7.804	7.947	7.947	7.969	7.566	7.949	8.442	8.305	7.915	NA	NA	NA	NA
us-gaap:IncreaseDecreaseInAccountsPayable	█▇█▄▅▃▅▁▁▂▃▄▆▄▃▄▆▃▆▄▃▄	21.885	17.07	22.159	3.222	7.403	-3.964	6.879	-11.526	-9.428	-8.499	-3.325	3.349	10.694	2.99	-2.954	1.463	11.28	-3.295	11.345	4.871	-0.742	3.716	NA	0.776	6.403	-2.963	14.257	0.491	-0.523	3.056	-4.659	2.004	2.203	2.452	NA	-0.287	-1.533	-1.379	8.552	-6.295	-4.828	NA	3.904	-4.815	-1.921	NA
us-gaap:IncreaseDecreaseInAccountsReceivable	▇▇▃█▁▅▁▂▄▄▂▂▆▄▂▃▆▅▄▄▅▅	36.908	32.973	-3.774	43.276	-23.371	9.457	-25.716	-16.023	7.442	5.8	-17.049	-12.893	25.064	8.417	-15.705	-5.247	20.772	11.267	0.373	4.016	10.433	10.413	NA	-2.992	17.356	3.91	3.334	-8.143	11.368	6.503	0.335	-3.898	10.501	9.745	NA	-11.169	34.435	-7.662	-14.017	17.034	6.62	NA	-11.279	15.799	2.182	NA
us-gaap:IncreaseDecreaseInInventories	█▄▅▁▆▂▂▁▁▃▅▅▃▃▃▄▄▃▂▂▃▃	32.053	6.152	10.814	-9.15	17.428	-6.667	-3.992	-11.872	-9.48	3.25	16.347	16.122	1.233	0.269	3.021	8.42	5.443	3.296	-4.034	-5.787	-2.202	3.484	NA	3.004	1.348	-0.149	-1.86	4.528	-1.184	0.774	0.949	7.891	0.278	-3.632	NA	-5.381	2.092	-0.437	-1.713	6.982	-2.895	NA	0.675	-2.288	-3.679	NA
us-gaap:NetCashProvidedByUsedInOperatingActivities	▆▄▇▅▄▃▆▆▄▂▆█▅▅▆▆▅▂▆▅▂▁	76.18	50.166	93.775	62.97	56.007	45.279	84.465	80.771	49.173	30.919	79.712	111.201	71.647	69.268	87.85	87.747	70.63	22.943	80.118	64.739	25.784	9.492	NA	51.619	38.734	23.23	49.31	61.318	31.004	11.509	31.556	46.806	22.96	16.045	NA	40.119	43.474	24.713	7.864	36.797	37.884	NA	13.717	29.138	48.795	NA
us-gaap:ProfitLoss	█▆▆▆▁▄▄▅▅▅▄▆▅▅▁▅▅▅▄▄▄▃▄▃▄▃▃▄▄▄▄▄▄▃	82.095	57.713	58.977	55.356	-8.991	24.644	22.654	35.647	43.792	36.989	32.665	53.546	42.326	36.029	-10.819	42.808	48.638	38.891	27.245	30.802	27.152	19.289	22.463	11.324	28.684	19.995	19.511	29.94	24.578	25.389	23.658	26.99	26.648	14.794	NA	9.841	23.998	23.604	17.889	15.238	24.939	25.269	21.578	19.578	23.338	20.278
us-gaap:ShareBasedCompensation	█▂▂▃▇▂▂▂▇▃▃▆▆█▃▃▄▂▂▂▃▁	8.843	3.395	3.585	3.692	7.887	2.965	3.308	3.488	8.284	3.966	4.278	7.27	7.169	8.714	3.878	3.847	5.007	3.583	2.821	3.042	3.92	2.204	NA	2.233	3.962	1.802	1.901	1.939	3.764	1.465	1.579	2.468	2.783	1.779	NA	1.774	1.849	2.36	1.365	1.304	1.461	NA	1.182	1.2	1.263	NA

		2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
us-gaap:NetCashProvidedByUsedInInvestingActivities	█▅███████████▁█▇███▅▆▂	-17.92	-122.02	-10.045	-11.998	-12.854	-16.536	-23.497	-13.148	-5.568	-14.244	-13.685	-17.829	-26.357	-324.377	-16.936	-43.084	-14.019	-22.098	-12.762	-124.278	-100.984	-273.219	NA	-6.227	-10.548	-12.273	-38.645	0.515	-7.455	-58.408	-6.945	-10.781	-153.945	-13.922	NA	-8.563	-11.087	-24.203	-7.839	-22.759	-15.628	NA	-4.447	-54.736	-8.551	NA
us-gaap:PaymentsToAcquirePropertyPlantAndEquipment	▅▄▄▂▃▅█▃▂▃▆▄▇▅▅▆▄▃▂▄▂▁	17.936	14.721	14.655	12.057	12.893	16.586	23.498	13.148	11.173	14.076	18.807	15.631	22.406	17.909	17.455	20.192	15.901	12.377	11.727	14.284	11.078	9.139	NA	8.628	14.109	12.279	12.859	6.29	6.709	6.423	9.625	10.883	8.992	5.453	NA	9.732	6.05	3.503	3.244	5.174	1.822	NA	4.614	6.693	8.585	NA

		2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
us-gaap:NetCashProvidedByUsedInFinancingActivities	▂▂▂▁▂▄▂▁▂▂▁▃▂█▂▃▂▃▃▄▂▇	-14.91	-34.273	-49.432	-68.902	-15.278	65.804	-10.811	-59.841	-44.291	-31.333	-73.362	-0.948	-44.101	240.308	-18.19	3.588	-13.017	2.938	21.815	73.594	-14.946	203.733	NA	-7.543	-11.164	-8.445	-84.716	-23.056	-0.912	65.431	-10.768	-5.222	146.882	11.34	NA	-5.702	1.814	-7.666	12.304	-10.231	-16.858	NA	8.689	17.594	-15.194	NA
us-gaap:RepaymentsOfLongTermDebt us-gaap:CreditFacility,us-gaap:DebtInstrument lfus:TermLoanCreditFacility,lfus:CreditAgreement		NA	NA	NA	0.0	2.5	NA	NA	NA	2.5	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA	NA
us-gaap:PaymentsOfDividends	████████▆▆▇▇▅▅▄▄▂▂▂▂▁▁	11.814	11.782	11.739	11.697	11.678	11.725	11.699	11.716	10.649	10.625	10.735	10.8	9.26	9.198	8.403	8.404	7.491	7.472	7.461	7.41	6.512	6.483	NA	6.568	5.661	5.635	5.632	5.622	4.977	4.944	4.933	4.924	4.455	4.41	NA	4.383	4.375	3.918	3.888	3.875	4.02	NA	3.284	NA	NA	NA

		2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03

Common Stock Value

us-gaap:CommonStockValue

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31	2011-01-01
Value	260000.0	259000.0	259000.0	258000.0	257000.0	256000.0	256000.0	256000.0	255000.0	254000.0	254000.0	254000.0	253000.0	251000.0	229000.0	229000.0	245000.0	228000.0	228000.0	224000.0	226000.0	225000.0	220000.0	216000.0	218000.0
Percentage of CommonStockValue	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

Weighted Average Number Of Diluted Shares Outstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

Period End	2021-06-26	2021-03-27	2020-09-26	2020-06-27	2020-03-28	2019-09-28	2019-06-29	2019-03-30	2018-09-29	2018-06-30	2018-03-31	2017-09-30	2017-07-01	2017-04-01	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-09-27	2014-06-28	2014-03-29	2013-09-28	2013-06-29	2013-03-30	2012-09-29	2012-06-30	2012-03-31	2011-10-01	2011-07-02	2011-04-02	2010-10-02	2010-07-03
Value	24	24	24	24	24	24	24	25	25	25	24	22	23	22	22	22	22	22	22	22	22	22	22	22	22	22	22	22	21	22	22	22	22	22
Percentage of WeightedAverageNumberOfDilutedSharesOutstanding	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

Weighted Average Number Of Shares Outstanding Basic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

Period End	2021-06-26	2021-03-27	2020-09-26	2020-06-27	2020-03-28	2019-09-28	2019-06-29	2019-03-30	2018-09-29	2018-06-30	2018-03-31	2017-09-30	2017-07-01	2017-04-01	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-09-27	2014-06-28	2014-03-29	2013-09-28	2013-06-29	2013-03-30	2012-09-29	2012-06-30	2012-03-31	2011-10-01	2011-07-02	2011-04-02	2010-10-02	2010-07-03
Value	24	24	24	24	24	24	24	24	25	25	24	22	22	22	22	22	22	22	22	22	22	22	22	22	22	22	21	21	21	22	22	21	21	22
Percentage of WeightedAverageNumberOfSharesOutstandingBasic	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount

us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28	2016-10-01	2016-07-02	2015-09-26	2015-06-27	2014-09-27
Value	41216.0	15.0	328620.0	153840.0	76845.0	60491.0	144030.0	113880.0	64520.0
Percentage of AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecurities

us-gaap:EmployeeStockOption

Period End	2020-09-26	2020-06-27	2020-03-28	2019-09-28	2019-06-29	2019-03-30	2018-09-29	2018-06-30	2018-03-31	2017-09-30	2017-07-01	2017-04-01	2016-10-01	2016-07-02	2016-04-02	2015-06-27	2015-03-28	2014-06-28	2014-03-29
Value	290260.0	328620.0	153840.0	205520.0	167600.0	77047.0	38082.0	47849.0	0	30579.0	46100.0	0	76845.0	60491.0	21888.0	113880.0	64520.0	46190.0	0
Percentage of AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	0.0	100.0	100.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	100.0	100.0	0.0	100.0	0.0	0.0	0.0

Earnings Per Share Basic

us-gaap:EarningsPerShareBasic

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
Value	3.34	2.35	2.41	2.27	-0.37	1.01	0.93	1.46	1.77	1.5	1.31	2.13	1.69	1.48	-0.48	1.88	2.13	1.71	1.2	1.36	1.21	0.86	0.5	1.26	0.88	0.86	1.33	1.09	1.13	1.05	1.2	1.19	0.67	0.55	1.09	1.08	0.83	0.71	1.13	1.13	0.98	0.9	1.06	0.91
Percentage of EarningsPerShareBasic	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

Earnings Per Share Diluted

us-gaap:EarningsPerShareDiluted

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
Value	3.3	2.32	2.39	2.25	-0.37	1.0	0.92	1.44	1.75	1.48	1.29	2.1	1.67	1.45	-0.48	1.87	2.11	1.69	1.19	1.35	1.2	0.85	0.5	1.26	0.88	0.86	1.32	1.08	1.12	1.04	1.19	1.18	0.66	0.53	1.08	1.07	0.81	0.7	1.12	1.11	0.96	0.88	1.04	0.9
Percentage of EarningsPerShareDiluted	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

Comprehensive Income Net Of Tax

us-gaap:ComprehensiveIncomeNetOfTax

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2011-12-31	2011-10-01	2011-07-02
Value	87	52	75	72	-11.408	9.665	28	18	38	45	32	45	26	35	-1.144	42	44	44	7.818	25	11	29	2.187	34	9.037	-8.569	13	33	19	30	36	17	7.662	6.575	34	15	5.281	7.301	28
Percentage of ComprehensiveIncomeNetOfTax	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	16.7	11.4	18.7	18.5	-3.7	2.8	8.4	5.1	9.6	11.1	8.0	10.4	5.7	8.6	-0.4	13.4	14.2	15.6	2.7	9.2	4.4	13.7	1.0	15.6	4.3	-4.1	6.1	15.3	9.4	15.3	18.3	9.6	4.5	4.1	19.9	8.7	3.6	4.2	16.4

Cost Of Goods And Services Sold

us-gaap:CostOfGoodsAndServicesSold

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
Value	326	303	260	253	208	222	225	231	256	250	247	259	290	268	178	184	180	171	170	166	174	132	129	136	133	131	130	137	128	121	120	114	106	99	104	106	99	93	105	106	102	88	96	98
Percentage of CostOfGoodsAndServicesSold	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	62.3	65.4	65.0	64.7	67.8	64.3	66.5	63.8	64.4	61.7	61.6	59.1	63.2	64.2	58.5	58.0	57.7	60.2	59.8	59.4	64.0	60.3	60.0	61.6	63.7	63.4	59.8	62.4	62.1	61.1	59.7	60.8	62.2	62.6	60.3	60.4	62.1	63.6	60.6	60.4	61.3	62.2	58.9	62.3

us-gaap:CostOfGoodsAndServicesSold us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceIncludingPortionAttributableToNoncontrollingInterest

Period End	2020-09-26	2020-06-27	2020-03-28	2019-09-28	2019-06-29	2019-03-30	2018-09-29	2018-06-30	2018-03-31	2017-09-30
Value	0.452	0.429	0.345	0.06	0.062	0.062	0.074	0.074	0.074	0.084
Percentage of CostOfGoodsAndServicesSold	0.2	0.2	0.2	0.0	0.0	0.0	0.0	0.0	0.0	0.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	0.1	0.1	0.1	0.0	0.0	0.0	0.0	0.0	0.0	0.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome us-gaap:AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceIncludingPortionAttributableToNoncontrollingInterest	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

Cost Of Revenue

us-gaap:CostOfRevenue

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
Value	326	303	260	253	208	222	225	231	256	250	247	259	290	268	178	184	180	171	170	166	174	132	129	136	133	131	130	137	128	121	120	114	106	99	104	106	99	93	105	106	102	88	96	98
Percentage of CostOfRevenue	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	62.3	65.4	65.0	64.7	67.8	64.3	66.5	63.8	64.4	61.7	61.6	59.1	63.2	64.2	58.5	58.0	57.7	60.2	59.8	59.4	64.0	60.3	60.0	61.6	63.7	63.4	59.8	62.4	62.1	61.1	59.7	60.8	62.2	62.6	60.3	60.4	62.1	63.6	60.6	60.4	61.3	62.2	58.9	62.3

Gross Profit

us-gaap:GrossProfit

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
Value	197	160	138	138	99	123	113	130	141	155	154	179	168	149	126	133	132	113	114	113	97	87	82	86	85	76	75	87	82	78	77	80	73	64	59	68	69	60	53	68	69	64	53	67	59
Percentage of GrossProfit	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	37.7	34.6	34.5	35.3	32.2	35.7	33.5	36.2	35.6	38.3	38.4	40.9	36.8	35.8	41.5	42.0	42.3	39.8	40.2	40.6	36.0	39.7	37.6	40.0	38.4	36.3	36.6	40.2	37.6	37.9	38.9	40.3	39.2	37.8	37.4	39.7	39.6	37.9	36.4	39.4	39.6	38.7	37.8	41.1	37.7

Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02
Value	95	72	68	67	-10.585	35	24	41	53	46	39	68	52	44	43	55	57	47	31	30	34	27	12	37	26	25	41	31	33	34	36	35	17	11	11	30	32	25	18	31	34	30
Percentage of IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	18.2	15.7	17.2	17.2	-3.4	10.3	7.2	11.4	13.5	11.5	9.9	15.5	11.4	10.7	14.3	17.5	18.3	16.6	11.2	10.9	12.5	12.3	5.9	17.0	12.6	12.1	18.9	14.3	16.3	17.3	18.2	18.9	10.5	7.1	7.1	17.9	18.4	15.8	12.7	17.9	19.7	18.3

Income Tax Expense Benefit

us-gaap:IncomeTaxExpenseBenefit

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
Value	13	14	9.936	12	-1.594	10	1.82	5.757	9.775	9.45	7.102	14	9.992	8.617	54	12	8.719	8.537	4.505	-0.369	6.862	7.788	1.317	9.033	6.411	5.561	11	6.984	8.423	13	9.534	8.749	3.178	1.486	6.995	8.828	7.411	3.417	6.118	9.512	9.03	4.611	10	8.282
Percentage of IncomeTaxExpenseBenefit	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	2.5	3.2	2.5	3.1	-0.5	3.1	0.5	1.6	2.5	2.3	1.8	3.3	2.2	2.1	17.9	4.0	2.8	3.0	1.6	-0.1	2.5	3.5	0.6	4.1	3.0	2.7	5.2	3.2	4.1	7.1	4.7	4.7	1.9	0.9	4.1	5.0	4.6	2.3	3.5	5.4	5.4	3.2	6.4	5.3

Interest Expense

us-gaap:InterestExpense

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
Value	4.626	4.673	4.816	4.988	5.855	5.418	5.432	5.559	5.589	5.686	5.589	5.775	5.782	5.423	3.512	3.467	3.281	3.12	2.342	2.571	1.67	2.045	0.922	0.948	1.151	1.167	1.292	1.228	1.216	0.958	0.939	0.644	0.376	0.403	0.403	0.454	0.421	0.423	0.42	0.414	0.521	0.336	0.341	0.313	0.356
Percentage of InterestExpense	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	0.9	1.0	1.2	1.3	1.9	1.6	1.6	1.5	1.4	1.4	1.4	1.3	1.3	1.3	1.2	1.1	1.0	1.1	0.8	0.9	0.6	0.9	0.4	0.4	0.5	0.6	0.6	0.6	0.6	0.5	0.5	0.3	0.2	0.3	0.3	0.3	0.2	0.3	0.3	0.2	0.3	0.2	0.2	0.2	0.2

Interest Expense Debt

us-gaap:InterestExpenseDebt

Period End	2021-06-26	2021-03-27	2020-09-26	2020-06-27	2020-03-28	2019-09-28	2019-06-29	2019-03-30	2018-09-29	2018-06-30	2018-03-31
Value	2.5	6.235	6.4	3.4	7.4	6.4	3.5	8.0	8.1	3.7	4.0
Percentage of InterestExpenseDebt	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	0.5	1.3	1.6	1.1	2.1	1.8	0.9	2.0	1.8	0.8	1.0

Operating Expenses

us-gaap:OperatingExpenses

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
Value	101	83	75	73	111	78	81	83	89	94	102	103	109	112	75	75	72	64	73	86	68	54	77	49	46	49	47	49	44	44	43	42	36	41	37	37	35	35	38	34	33	29	33	31
Percentage of OperatingExpenses	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	19.3	18.1	18.8	18.8	36.1	22.8	24.0	23.1	22.4	23.3	25.5	23.5	23.8	26.8	24.9	23.6	23.1	22.7	25.8	30.8	25.1	24.9	36.0	22.1	22.2	23.8	21.7	22.3	21.7	22.4	21.6	22.5	21.3	26.1	21.8	21.3	21.8	24.1	22.4	19.6	20.2	20.8	20.3	20.2

Operating Income Loss

us-gaap:OperatingIncomeLoss

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
Value	96	76	65	64	-11.95	44	32	47	52	60	51	76	59	37	50	58	60	48	40	27	29	32	29	8.584	36	29	26	40	33	33	32	37	31	28	18	18	30	32	25	18	29	35	30	24	34	27
Percentage of OperatingIncomeLoss	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	18.4	16.5	16.2	16.5	-3.9	12.9	9.5	13.0	13.2	15.0	12.8	17.4	13.0	9.0	16.7	18.4	19.2	17.1	14.4	9.8	10.9	14.8	13.6	4.0	16.3	14.0	12.8	18.4	15.3	16.2	16.6	18.7	16.7	16.5	11.3	11.3	17.9	18.3	16.1	12.3	17.0	20.0	18.5	17.0	20.9	17.5

us-gaap:OperatingIncomeLoss us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:CorporateNonSegment, us-gaap:AllOtherSegments

Period End	2021-06-26	2021-03-27	2020-09-26	2020-06-27	2020-03-28	2019-09-28	2019-06-29	2019-03-30	2018-09-29
Value	-5.612	-2.864	-1.583	-35.721	-5.172	-5.659	-7.176	-5.069	-11.233
Percentage of OperatingIncomeLoss	-5.8	-3.7	-2.5	298.9	-11.6	-12.0	-13.6	-8.4	-14.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	-1.1	-0.6	-0.4	-11.6	-1.5	-1.6	-1.8	-1.3	-2.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:CorporateNonSegment us-gaap:AllOtherSegments	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

us-gaap:OperatingSegments, lfus:Automotive

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29
Value	21	15	-8.857	14	11	11	10	13	10	10
Percentage of OperatingIncomeLoss	32.3	23.8	74.1	31.5	36.3	24.2	19.7	21.8	19.4	14.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	5.2	3.9	-2.9	4.1	3.5	3.2	2.6	3.3	2.5	2.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments lfus:Automotive	0.0	0.0	0.0	13.5	0.0	10.9	0.0	11.6	0.0	9.5

us-gaap:OperatingSegments, lfus:AutomotiveSegment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	19	20	-8.857	14
Percentage of OperatingIncomeLoss	20.0	26.6	74.1	31.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	3.7	4.4	-2.9	4.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments lfus:AutomotiveSegment	0.0	0.0	0.0	0.0

us-gaap:OperatingSegments, lfus:Electronics

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29
Value	41	45	32	32	18	34	43	49	47	72
Percentage of OperatingIncomeLoss	64.5	71.0	-273.2	72.1	56.8	73.3	82.9	80.8	92.4	95.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	10.5	11.7	10.6	9.3	5.4	9.5	11.0	12.1	11.9	16.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments lfus:Electronics	0.0	0.0	0.0	15.1	0.0	15.2	0.0	18.5	0.0	24.4

us-gaap:OperatingSegments, lfus:ElectronicsSegment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	74	55	32	32
Percentage of OperatingIncomeLoss	77.1	72.6	-273.2	72.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	14.2	12.0	10.6	9.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments lfus:ElectronicsSegment	0.0	0.0	0.0	0.0

us-gaap:OperatingSegments, lfus:Industrial

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29
Value	3.587	4.898	-0.023	3.534	6.249	6.822	5.831	3.505	3.212	4.134
Percentage of OperatingIncomeLoss	5.5	7.6	0.2	7.9	19.3	14.5	11.1	5.8	6.2	5.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	0.9	1.3	-0.0	1.0	1.8	1.9	1.5	0.9	0.8	0.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments lfus:Industrial	0.0	0.0	0.0	13.0	0.0	22.7	0.0	13.2	0.0	14.6

us-gaap:OperatingSegments, lfus:IndustrialSegment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	8.375	3.506	-0.023	3.534
Percentage of OperatingIncomeLoss	8.7	4.6	0.2	7.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	1.6	0.8	-0.0	1.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:OperatingSegments lfus:IndustrialSegment	0.0	0.0	0.0	0.0

Other Comprehensive Income Loss Net Of Tax

us-gaap:OtherComprehensiveIncomeLossNetOfTax

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30
Value	16	16	-2.417	-14.979	5.785	-17.026	-5.731	8.073	-0.293	-7.947	-15.942	-0.279	9.675	-0.239
Percentage of OtherComprehensiveIncomeLossNetOfTax	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	4.0	4.3	-0.8	-4.3	1.7	-4.7	-1.4	2.0	-0.1	-1.8	-3.5	-0.1	3.2	-0.1

us-gaap:OtherComprehensiveIncomeLossNetOfTax us-gaap:StatementEquityComponents

us-gaap:AccumulatedDefinedBenefitPlansAdjustment

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29
Value	-6.38	0.563	-10.839	0.561	-8.336	0.137	0.161	-0.049	0.229	-0.115
Percentage of OtherComprehensiveIncomeLossNetOfTax	-39.7	3.3	448.4	-3.7	-144.1	-0.8	-2.8	-0.6	-78.2	1.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	-1.6	0.1	-3.5	0.2	-2.5	0.0	0.0	-0.0	0.1	-0.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:AccumulatedDefinedBenefitPlansAdjustment	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

us-gaap:AccumulatedOtherComprehensiveIncome

Period End	2020-09-26	2020-06-27	2020-03-28	2019-09-28	2019-06-29	2019-03-30	2018-09-29	2018-06-30	2018-03-31
Value	16	-2.417	-14.979	-17.026	-5.731	8.073	-7.947	-15.942	-0.279
Percentage of OtherComprehensiveIncomeLossNetOfTax	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	4.3	-0.8	-4.3	-4.7	-1.4	2.0	-1.8	-3.5	-0.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:AccumulatedOtherComprehensiveIncome	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

us-gaap:AccumulatedTranslationAdjustment

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29
Value	22	16	8.422	-15.54	14	-17.163	-5.892	8.122	-0.522	-7.832
Percentage of OtherComprehensiveIncomeLossNetOfTax	139.7	96.7	-348.4	103.7	244.1	100.8	102.8	100.6	178.2	98.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	5.6	4.2	2.7	-4.5	4.2	-4.7	-1.5	2.0	-0.1	-1.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:AccumulatedTranslationAdjustment	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

Other Income

us-gaap:OtherIncome us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents

us-gaap:OtherIncome

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceIncludingPortionAttributableToNoncontrollingInterest

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	509000.0	504000.0	429000.0	345000.0
Percentage of OtherIncome	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	0.1	0.1	0.1	0.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome us-gaap:AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceIncludingPortionAttributableToNoncontrollingInterest	0.0	0.0	0.0	0.0

Other Nonoperating Income Expense

us-gaap:OtherNonoperatingIncomeExpense

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
Value	1890000.0	7737000.0	3440000.0	1682000.0	1210000.0	-1249000.0	-2823000.0	4764000.0	2947000.0	-4305000.0	-763000.0	-1259000.0	1678000.0	1943000.0	320000.0	1013000.0	-190000.0	139000.0	690000.0	778000.0	-255000.0	517000.0	1430000.0	1202000.0	1126000.0	1751000.0	2261000.0	1446000.0	1186000.0	1103000.0	1380000.0	4659000.0	909000.0	4224000.0	1045000.0	516000.0	757000.0	-101000.0	954000.0	1897000.0	11000.0	26000.0	214000.0	29000.0	1409000.0
Percentage of OtherNonoperatingIncomeExpense	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	0.4	1.7	0.9	0.4	0.4	-0.4	-0.8	1.3	0.7	-1.1	-0.2	-0.3	0.4	0.5	0.1	0.3	-0.1	0.0	0.2	0.3	-0.1	0.2	0.7	0.5	0.5	0.8	1.0	0.7	0.6	0.6	0.7	2.5	0.5	2.7	0.7	0.3	0.4	-0.1	0.6	1.1	0.0	0.0	0.2	0.0	0.9

Profit Loss

us-gaap:ProfitLoss

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
Value	82	57	58	55	-8.991	24	22	35	43	36	32	53	42	36	-10.819	42	48	38	27	30	27	19	22	11	28	19	19	29	24	25	23	26	26	14	9.841	23	23	17	15	24	25	21	19	23	20
Percentage of ProfitLoss	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	15.7	12.4	14.7	14.1	-2.9	7.1	6.7	9.8	11.0	9.1	8.1	12.2	9.2	8.6	-3.5	13.5	15.5	13.6	9.6	11.0	10.0	8.8	10.2	5.3	12.9	9.5	9.4	13.8	11.1	12.3	11.9	13.4	14.2	8.7	6.2	13.9	13.4	11.1	10.4	14.3	14.3	12.9	13.7	14.3	12.9

us-gaap:ProfitLoss us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings

Period End	2021-06-26	2021-03-27	2020-09-26	2020-06-27	2020-03-28	2019-09-28	2019-06-29	2019-03-30	2018-09-29	2018-06-30	2018-03-31
Value	82	57	55	-8.991	24	35	43	36	53	42	36
Percentage of ProfitLoss	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	15.7	12.4	14.1	-2.9	7.1	9.8	11.0	9.1	12.2	9.2	8.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:RetainedEarnings	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

Research And Development Expense

us-gaap:ResearchAndDevelopmentExpense

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
Value	16	14	11	13	13	14	17	19	21	21	21	20	22	22	13	11	12	12	11	10	11	8.565	7.479	7.361	7.384	8.289	7.449	7.81	7.574	6.69	6.217	5.793	5.715	5.678	5.505	4.887	5.161	4.685	5.297	4.662	4.795	4.904	4.345	4.403
Percentage of ResearchAndDevelopmentExpense	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	3.1	3.2	2.9	3.3	4.4	4.2	5.3	5.5	5.4	5.3	5.4	4.7	5.0	5.4	4.5	3.8	4.1	4.3	4.0	3.7	4.4	3.9	3.5	3.3	3.5	4.0	3.4	3.5	3.7	3.4	3.1	3.1	3.3	3.6	3.2	2.8	3.2	3.2	3.0	2.6	2.9	3.4	2.7	2.8

Revenue From Contract With Customer Including Assessed Tax

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
Value	523	463	400	391	307	346	338	361	397	405	402	439	459	417	304	317	313	285	284	280	271	219	220	215	222	210	206	217	220	206	198	201	187	170	158	158	172	175	160	147	173	176	167	142	163	157
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:ProductOrService

lfus:AutomotiveSensors

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	26	28	29	26	13	24	37	23	24	26	32	27	30	31
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	5.1	6.1	7.4	6.7	4.5	7.0	11.0	6.6	6.2	6.4	8.0	6.2	6.7	7.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	5.1	6.1	7.4	6.7	4.5	7.0	11.0	6.6	6.2	6.4	8.0	6.2	6.7	7.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax lfus:AutomotiveSensors	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

lfus:CommercialVehicleProducts

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	38	32	29	25	17	27	10	26	30	30	24	29	32	31
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	7.4	7.0	7.4	6.6	5.8	8.1	3.0	7.4	7.6	7.6	6.0	6.7	7.2	7.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	7.4	7.0	7.4	6.6	5.8	8.1	3.0	7.4	7.6	7.6	6.0	6.7	7.2	7.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax lfus:CommercialVehicleProducts	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

lfus:ElectronicsPassiveProductsAndSensors

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	155	132	129	108	92	84	251	94	108	108	281	124	128	114
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	29.7	28.6	32.4	27.6	30.2	24.4	74.4	26.2	27.3	26.7	70.1	28.3	27.9	27.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	29.7	28.6	32.4	27.6	30.2	24.4	74.4	26.2	27.3	26.7	70.1	28.3	27.9	27.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax lfus:ElectronicsPassiveProductsAndSensors	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

lfus:ElectronicsSemiconductor

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	170	154	115	147	130	129	-43.067	132	151	157	-17.921	172	171	149
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	32.5	33.2	28.8	37.6	42.4	37.4	-12.7	36.6	38.0	38.7	-4.5	39.2	37.2	35.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	32.5	33.2	28.8	37.6	42.4	37.4	-12.7	36.6	38.0	38.7	-4.5	39.2	37.2	35.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax lfus:ElectronicsSemiconductor	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

lfus:IndustrialProducts

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	64	48	31	31	22	27	27	30	29	26	26	28	32	27
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	12.4	10.5	7.9	8.0	7.2	7.8	8.2	8.3	7.5	6.6	6.5	6.4	7.1	6.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	12.4	10.5	7.9	8.0	7.2	7.8	8.2	8.3	7.5	6.6	6.5	6.4	7.1	6.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax lfus:IndustrialProducts	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

lfus:PassengerCarProducts

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	68	67	64	52	30	52	54	53	53	56	55	57	63	63
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	13.0	14.6	16.2	13.5	9.9	15.2	16.0	14.9	13.6	13.9	13.8	13.2	13.8	15.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	13.0	14.6	16.2	13.5	9.9	15.2	16.0	14.9	13.6	13.9	13.8	13.2	13.8	15.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax lfus:PassengerCarProducts	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:ProductOrService, us-gaap:StatementBusinessSegments

lfus:AutomotiveSensors, lfus:Automotive

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	29	26	13	24	37	23	24	26	32	27	30	31
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	7.4	6.7	4.5	7.0	11.0	6.6	6.2	6.4	8.0	6.2	6.7	7.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	7.4	6.7	4.5	7.0	11.0	6.6	6.2	6.4	8.0	6.2	6.7	7.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax lfus:AutomotiveSensors lfus:Automotive	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

lfus:AutomotiveSensors, lfus:AutomotiveSegment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	26	28	13	24
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	5.1	6.1	4.5	7.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	5.1	6.1	4.5	7.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax lfus:AutomotiveSensors lfus:AutomotiveSegment	100.0	100.0	100.0	100.0

lfus:CommercialVehicleProducts, lfus:Automotive

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	29	25	17	27	10	26	30	30	24	29	32	31
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	7.4	6.6	5.8	8.1	3.0	7.4	7.6	7.6	6.0	6.7	7.2	7.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	7.4	6.6	5.8	8.1	3.0	7.4	7.6	7.6	6.0	6.7	7.2	7.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax lfus:CommercialVehicleProducts lfus:Automotive	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

lfus:CommercialVehicleProducts, lfus:AutomotiveSegment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	38	32	17	27
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	7.4	7.0	5.8	8.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	7.4	7.0	5.8	8.1
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax lfus:CommercialVehicleProducts lfus:AutomotiveSegment	100.0	100.0	100.0	100.0

lfus:ElectronicsPassiveProductsAndSensors, lfus:Electronics

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	129	108	92	84	251	94	108	108	281	124	128	114
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	32.4	27.6	30.2	24.4	74.4	26.2	27.3	26.7	70.1	28.3	27.9	27.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	32.4	27.6	30.2	24.4	74.4	26.2	27.3	26.7	70.1	28.3	27.9	27.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax lfus:ElectronicsPassiveProductsAndSensors lfus:Electronics	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

lfus:ElectronicsPassiveProductsAndSensors, lfus:ElectronicsSegment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	155	132	92	84
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	29.7	28.6	30.2	24.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	29.7	28.6	30.2	24.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax lfus:ElectronicsPassiveProductsAndSensors lfus:ElectronicsSegment	100.0	100.0	100.0	100.0

lfus:ElectronicsSemiconductor, lfus:Electronics

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	115	147	130	129	-43.067	132	151	157	-17.921	172	171	149
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	28.8	37.6	42.4	37.4	-12.7	36.6	38.0	38.7	-4.5	39.2	37.2	35.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	28.8	37.6	42.4	37.4	-12.7	36.6	38.0	38.7	-4.5	39.2	37.2	35.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax lfus:ElectronicsSemiconductor lfus:Electronics	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

lfus:ElectronicsSemiconductor, lfus:ElectronicsSegment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	170	154	130	129
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	32.5	33.2	42.4	37.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	32.5	33.2	42.4	37.4
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax lfus:ElectronicsSemiconductor lfus:ElectronicsSegment	100.0	100.0	100.0	100.0

lfus:IndustrialProducts, lfus:Industrial

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	31	31	22	27	27	30	29	26	26	28	32	27
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	7.9	8.0	7.2	7.8	8.2	8.3	7.5	6.6	6.5	6.4	7.1	6.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	7.9	8.0	7.2	7.8	8.2	8.3	7.5	6.6	6.5	6.4	7.1	6.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax lfus:IndustrialProducts lfus:Industrial	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

lfus:IndustrialProducts, lfus:IndustrialSegment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	64	48	22	27
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	12.4	10.5	7.2	7.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	12.4	10.5	7.2	7.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax lfus:IndustrialProducts lfus:IndustrialSegment	100.0	100.0	100.0	100.0

lfus:PassengerCarProducts, lfus:Automotive

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	64	52	30	52	54	53	53	56	55	57	63	63
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	16.2	13.5	9.9	15.2	16.0	14.9	13.6	13.9	13.8	13.2	13.8	15.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	16.2	13.5	9.9	15.2	16.0	14.9	13.6	13.9	13.8	13.2	13.8	15.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax lfus:PassengerCarProducts lfus:Automotive	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

lfus:PassengerCarProducts, lfus:AutomotiveSegment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	68	67	30	52
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	13.0	14.6	9.9	15.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	13.0	14.6	9.9	15.2
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax lfus:PassengerCarProducts lfus:AutomotiveSegment	100.0	100.0	100.0	100.0

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:StatementBusinessSegments

lfus:Automotive

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02
Value	124	104	61	104	101	104	108	113	112	114	127	126	115	113	116	107	105	106	111	91	81	85	84	80	80	82	82	72	70	64	59	50	50	51	51	52	45	47	50
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	31.0	26.7	20.2	30.3	30.0	28.9	27.3	28.0	27.9	26.1	27.7	30.2	37.8	35.8	37.2	37.8	37.1	37.9	41.0	41.9	37.8	38.7	40.0	38.9	37.1	37.1	39.8	36.8	35.0	34.4	34.7	31.7	31.7	30.0	29.3	32.8	31.0	27.4	28.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	31.0	26.7	20.2	30.3	30.0	28.9	27.3	28.0	27.9	26.1	27.7	30.2	37.8	35.8	37.2	37.8	37.1	37.9	41.0	41.9	37.8	38.7	40.0	38.9	37.1	37.1	39.8	36.8	35.0	34.4	34.7	31.7	31.7	30.0	29.3	32.8	31.0	27.4	28.5
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax lfus:Automotive	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

lfus:AutomotiveSegment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	133	128	61	104
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	25.5	27.7	20.2	30.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	25.5	27.7	20.2	30.3
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax lfus:AutomotiveSegment	100.0	100.0	100.0	100.0

lfus:Electronics

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02
Value	244	255	223	214	208	227	259	265	264	296	299	264	162	175	169	153	156	147	132	98	102	105	99	96	107	109	95	95	101	91	79	75	75	87	89	77	72	96	98
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	61.1	65.2	72.6	61.9	61.7	62.8	65.2	65.4	65.6	67.5	65.2	63.3	53.4	55.3	54.1	53.9	55.0	52.7	48.6	45.0	47.6	47.5	47.3	46.6	49.5	49.8	46.3	48.0	50.2	48.7	46.5	47.3	47.3	50.8	50.9	48.0	49.2	55.3	55.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	61.1	65.2	72.6	61.9	61.7	62.8	65.2	65.4	65.6	67.5	65.2	63.3	53.4	55.3	54.1	53.9	55.0	52.7	48.6	45.0	47.6	47.5	47.3	46.6	49.5	49.8	46.3	48.0	50.2	48.7	46.5	47.3	47.3	50.8	50.9	48.0	49.2	55.3	55.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax lfus:Electronics	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

lfus:ElectronicsSegment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	325	286	223	214
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	62.1	61.8	72.6	61.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	62.1	61.8	72.6	61.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax lfus:ElectronicsSegment	100.0	100.0	100.0	100.0

lfus:Industrial

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28
Value	31	31	22	27	27	30	29	26	26	28	32	27	26	28	27	23	22	26	28	28	31	30	26
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	7.9	8.0	7.2	7.8	8.2	8.3	7.5	6.6	6.5	6.4	7.1	6.5	8.8	8.9	8.8	8.4	7.9	9.4	10.4	13.1	14.6	13.8	12.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	7.9	8.0	7.2	7.8	8.2	8.3	7.5	6.6	6.5	6.4	7.1	6.5	8.8	8.9	8.8	8.4	7.9	9.4	10.4	13.1	14.6	13.8	12.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax lfus:Industrial	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

lfus:IndustrialSegment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	64	48	22	27
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	12.4	10.5	7.2	7.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	12.4	10.5	7.2	7.8
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax lfus:IndustrialSegment	100.0	100.0	100.0	100.0

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:StatementGeographical

country:CN

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30
Value	156	139	123	126	102	86	99	101	107	57	116	117	127	106	80	82	86	78	82	70	62	48	49	49	44	55	45	39	37	43	43	37	33
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	29.8	30.0	30.8	32.3	33.2	24.9	29.5	28.2	27.1	14.1	28.9	26.8	27.8	25.5	26.4	26.1	27.7	27.4	29.0	25.0	23.0	22.1	22.9	22.5	21.1	26.6	21.1	18.1	18.0	22.0	21.7	20.1	19.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	29.8	30.0	30.8	32.3	33.2	24.9	29.5	28.2	27.1	14.1	28.9	26.8	27.8	25.5	26.4	26.1	27.7	27.4	29.0	25.0	23.0	22.1	22.9	22.5	21.1	26.6	21.1	18.1	18.0	22.0	21.7	20.1	19.7
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax country:CN	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

country:US

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30
Value	154	130	106	106	76	102	99	105	115	119	124	125	137	123	92	103	100	86	86	92	93	85	85	89	83	69	85	80	71	71	76	68	57
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	29.6	28.2	26.6	27.1	25.0	29.7	29.4	29.1	29.2	29.5	31.0	28.7	29.9	29.6	30.3	32.5	32.1	30.4	30.2	33.0	34.2	38.8	39.5	40.4	39.6	33.8	39.2	36.4	34.7	36.3	37.9	36.6	33.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	29.6	28.2	26.6	27.1	25.0	29.7	29.4	29.1	29.2	29.5	31.0	28.7	29.9	29.6	30.3	32.5	32.1	30.4	30.2	33.0	34.2	38.8	39.5	40.4	39.6	33.8	39.2	36.4	34.7	36.3	37.9	36.6	33.9
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax country:US	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

lfus:OtherCountries

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31
Value	212	193	170	158	128	157	139	154	174	228	161	195	194	187	131	131	125	120	115	117	116	85	81	82	82	81	86	100	97	82	81	81	79	71	77	78	74
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	40.6	41.8	42.6	40.6	41.8	45.4	41.1	42.7	43.8	56.4	40.2	44.5	42.3	44.9	43.3	41.4	40.2	42.2	40.7	42.0	42.8	39.1	37.6	37.2	39.2	39.6	39.7	45.5	47.3	41.7	40.4	43.4	46.4	45.2	44.8	44.8	46.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	40.6	41.8	42.6	40.6	41.8	45.4	41.1	42.7	43.8	56.4	40.2	44.5	42.3	44.9	43.3	41.4	40.2	42.2	40.7	42.0	42.8	39.1	37.6	37.2	39.2	39.6	39.7	45.5	47.3	41.7	40.4	43.4	46.4	45.2	44.8	44.8	46.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax lfus:OtherCountries	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

Selling General And Administrative Expense

us-gaap:SellingGeneralAndAdministrativeExpense

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
Value	73	58	45	50	53	54	53	54	57	62	67	69	73	77	55	56	53	46	56	56	51	42	37	38	36	37	36	38	34	34	34	34	29	34	30	31	28	28	32	28	27	23	27	26
Percentage of SellingGeneralAndAdministrativeExpense	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	14.0	12.6	11.4	12.9	17.6	15.7	15.7	15.0	14.5	15.5	16.8	15.9	16.0	18.6	18.3	17.9	17.1	16.4	19.7	20.2	18.8	19.3	17.2	17.5	17.3	18.3	16.8	17.4	16.5	17.4	17.1	18.3	17.1	21.5	17.7	17.7	17.7	19.6	18.4	16.1	16.4	16.4	16.9	16.6

Assets

us-gaap:Assets

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-01-01
Value	2927	2786	2747	2654	2611	2612	2559	2551	2621	2625	2614	2663	2587	2627	1740	1702	1622	1544	1491	1458	1341	1403	1064	1091	1099	1059	1070	1133	1128	1095	1024	1006	959	787	777	763	725	716	678	687	696	621
Percentage of Assets	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

Liabilities And Stockholders Equity

us-gaap:LiabilitiesAndStockholdersEquity

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-01-01
Value	2927	2786	2747	2654	2611	2612	2559	2551	2621	2625	2614	2663	2587	2627	1740	1702	1622	1544	1491	1458	1341	1403	1064	1091	1099	1059	1070	1133	1128	1095	1024	1006	959	787	777	763	725	716	678	687	696	621
Percentage of LiabilitiesAndStockholdersEquity	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

Stockholders Equity

us-gaap:StockholdersEquity

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31	2011-01-01
Value	1742	1660	1608	1529	1462	1476	1495	1472	1509	1505	1478	1519	1469	1441	927	933	895	855	814	744	727	686	587	500	452
Percentage of StockholdersEquity	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	59.5	59.6	58.5	57.6	56.0	56.5	58.4	57.7	57.6	57.3	56.5	57.0	56.8	54.9	53.3	54.8	55.2	55.4	54.6	69.9	67.9	67.0	75.5	73.8	72.9

Assets Current

us-gaap:AssetsCurrent

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-01-01
Value	1318	1192	1217	1148	1119	1092	1004	1007	1039	1030	1032	1052	958	973	792	759	704	634	612	555	519	605	583	613	603	566	571	645	629	597	565	557	516	465	445	429	403	416	378	388	393	318
Percentage of AssetsCurrent	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	45.1	42.8	44.3	43.3	42.9	41.8	39.2	39.5	39.7	39.2	39.5	39.5	37.0	37.0	45.5	44.6	43.5	41.1	41.0	38.1	38.7	43.2	54.8	56.2	54.9	53.5	53.4	56.9	55.8	54.5	55.2	55.3	53.8	59.1	57.3	56.3	55.6	58.2	55.8	56.5	56.5	51.4

Cash And Cash Equivalents At Carrying Value

us-gaap:CashAndCashEquivalentsAtCarryingValue

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2015-01-03	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03	2010-01-02	2008-12-27
Value	616	572	687	641	651	620	531	476	474	476	489	498	408	412	429	372	321	277	275	194	179	272	328	336	311	293	297	297	378	346	319	305	292	257	246	235	207	168	178	164	163	163	131	109	118	87	70	70
Percentage of CashAndCashEquivalentsAtCarryingValue	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	21.1	20.6	25.0	24.2	25.0	23.8	20.7	18.7	18.1	18.2	18.7	18.7	15.8	15.7	24.7	21.9	19.8	18.0	18.4	13.3	13.4	19.4	30.9	30.8	28.4	27.7	0.0	27.8	33.4	30.7	29.2	29.8	29.1	26.8	31.3	30.3	27.2	23.3	24.9	24.2	23.8	23.5	0.0	17.7	0.0	0.0	0.0	0.0

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2017-12-30	2016-12-31
Value	621	577	687	641	651	620	531	476	474	476	489	498	429	275
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	21.2	20.7	25.0	24.2	25.0	23.8	20.7	18.7	18.1	18.2	18.7	18.7	24.7	18.4

Short Term Investments

us-gaap:ShortTermInvestments

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2012-06-30	2012-03-31	2011-12-31
Value	0.018	0.053	0.054	0.052	0.044	0.043	0.044	0.033	0.034	0.033	0.034	0.035	0.034	0.037	0.035	0.035	0.034	0.032	3.69	3.961	3.92	4.354	4.179	3.958	3.954	3.869	4.302	0.038	6.849	6.943	6.886	5.475	19	13
Percentage of ShortTermInvestments	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.2	0.3	0.3	0.3	0.4	0.4	0.4	0.4	0.4	0.0	0.6	0.6	0.7	0.8	2.7	2.1

Accounts Receivable Net Current

us-gaap:AccountsReceivableNetCurrent

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-01-01
Value	313	276	232	231	185	207	202	226	245	237	232	251	260	244	182	197	199	212	198	205	197	181	142	145	151	136	135	134	144	136	127	129	131	107	100	109	115	106	92	110	118	97
Percentage of AccountsReceivableNetCurrent	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	10.7	9.9	8.5	8.7	7.1	8.0	7.9	8.9	9.4	9.1	8.9	9.4	10.1	9.3	10.5	11.6	12.3	13.8	13.3	14.1	14.7	12.9	13.4	13.3	13.8	12.9	12.6	11.9	12.8	12.4	12.5	12.8	13.7	13.6	12.9	14.3	16.0	14.9	13.6	16.1	17.0	15.7

Inventory Net

us-gaap:InventoryNet

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-01-01
Value	325	295	258	243	248	227	237	240	254	261	258	247	239	263	140	136	125	118	114	121	124	133	98	99	97	96	97	99	96	99	92	91	83	71	75	81	80	77	75	82	79	80
Percentage of InventoryNet	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	11.1	10.6	9.4	9.2	9.5	8.7	9.3	9.4	9.7	10.0	9.9	9.3	9.2	10.0	8.1	8.0	7.7	7.7	7.6	8.3	9.3	9.5	9.3	9.1	8.9	9.1	9.1	8.8	8.6	9.0	9.0	9.1	8.7	9.1	9.7	10.6	11.1	10.8	11.1	12.0	11.5	12.9

Inventory Finished Goods

us-gaap:InventoryFinishedGoods

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2011-12-31
Value	142	130	114	105	106	100	110	49	50	46	35	41	37	42	41	38	37
Percentage of InventoryFinishedGoods	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	4.9	4.7	4.2	4.0	4.1	3.8	4.3	4.4	4.6	4.6	3.5	4.4	4.8	5.4	5.4	5.3	5.6

Inventory Raw Materials And Supplies

us-gaap:InventoryRawMaterialsAndSupplies

Period End	2020-12-26	2019-12-28
Value	85	76
Percentage of InventoryRawMaterialsAndSupplies	100.0	100.0
Percentage of Assets	3.1	3.0

Prepaid Expense And Other Assets Current

us-gaap:PrepaidExpenseAndOtherAssetsCurrent

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2011-12-31
Value	59	43	35	30	31	32	28	62	63	53	49	48	45	47	37	45	51	13	9.438	15	14	14	8.959	14	15	13	13	16	18	19	17	17	18	15	16	13	14
Percentage of PrepaidExpenseAndOtherAssetsCurrent	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	2.0	1.6	1.3	1.1	1.2	1.2	1.1	2.4	2.4	2.0	1.9	1.8	1.8	1.8	2.2	2.7	3.2	0.8	0.6	1.1	1.1	1.0	0.8	1.3	1.4	1.3	1.3	1.5	1.6	1.8	1.7	1.8	2.0	2.0	2.1	1.8	2.1

Noncurrent Assets

us-gaap:NoncurrentAssets

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2011-12-31	2011-01-01
Value	352	344	344	339	334	334	344	329	338	342	339	343	338	337	250	244	232	223	217	223	224	229	162	162	166	160	158	150	146	141	120	303	301	289	279	284
Percentage of NoncurrentAssets	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	12.1	12.4	12.5	12.8	12.8	12.8	13.5	12.9	12.9	13.0	13.0	12.9	13.1	12.8	14.4	14.4	14.3	14.5	14.6	15.4	16.7	16.4	15.3	14.9	15.1	15.2	14.8	14.7	14.5	14.7	15.3	39.0	39.5	39.9	41.1	45.8

us-gaap:NoncurrentAssets us-gaap:StatementGeographical

country:CN

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2013-12-28	2012-12-29
Value	87	85	85	82	82	83	88	88	92	94	95	89	92	91	86	80	70	65	65	67	70	78	37	37	40	39	40	45	41
Percentage of NoncurrentAssets	24.8	24.7	25.0	24.4	24.6	25.0	25.6	26.8	27.4	27.7	28.2	26.1	27.4	27.2	34.4	32.9	30.4	29.1	30.1	29.9	31.3	34.3	22.9	23.3	24.3	24.4	25.8	30.5	13.7
Percentage of Assets	3.0	3.1	3.1	3.1	3.1	3.2	3.4	3.5	3.5	3.6	3.7	3.4	3.6	3.5	5.0	4.7	4.4	4.2	4.4	4.6	5.2	5.6	3.5	3.5	3.7	3.7	3.8	4.5	5.3
Percentage of Assets country:CN	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

country:DE

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2016-12-31
Value	37	36	37	37	36	35	36	35	37	35	36	37	35	36	1.082	1.313
Percentage of NoncurrentAssets	10.6	10.5	11.0	11.1	11.0	10.6	10.5	10.9	11.2	10.4	10.8	10.8	10.3	10.7	0.4	0.6
Percentage of Assets	1.3	1.3	1.4	1.4	1.4	1.4	1.4	1.4	1.4	1.4	1.4	1.4	1.4	1.4	0.1	0.1
Percentage of Assets country:DE	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

country:MX

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-01-02	2015-09-26	2015-06-27	2014-12-27
Value	76	72	70	68	67	69	73	73	74	73	70	69	66	64	62	61	60	58	52	51	47	13	46	47
Percentage of NoncurrentAssets	21.7	21.0	20.4	20.1	20.3	20.8	21.2	22.2	21.9	21.5	20.7	20.2	19.5	19.0	24.9	25.2	25.9	25.9	24.1	23.2	29.0	8.4	27.7	30.2
Percentage of Assets	2.6	2.6	2.6	2.6	2.6	2.7	2.9	2.9	2.8	2.8	2.7	2.6	2.6	2.4	3.6	3.6	3.7	3.8	3.5	3.6	4.4	1.2	4.2	4.5
Percentage of Assets country:MX	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

country:PH

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-01-02
Value	69	66	66	64	58	55	51	37	37	36	32	31	31	30	31	30	31	32	33	34	33
Percentage of NoncurrentAssets	19.6	19.4	19.5	18.9	17.4	16.5	15.0	11.5	11.0	10.6	9.5	9.2	9.3	9.1	12.4	12.6	13.6	14.6	15.4	15.4	20.6
Percentage of Assets	2.4	2.4	2.4	2.4	2.2	2.1	2.0	1.5	1.4	1.4	1.2	1.2	1.2	1.2	1.8	1.8	1.9	2.1	2.2	2.4	3.1
Percentage of Assets country:PH	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

country:US

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2013-12-28	2012-12-29
Value	47	48	46	52	54	54	58	56	58	57	58	66	59	49	23	23	23	23	23	24	23	24	23	27	34	35	34	27	14
Percentage of NoncurrentAssets	13.5	14.2	13.4	15.3	16.2	16.4	16.9	17.2	17.1	16.8	17.3	19.2	17.4	14.6	9.4	9.8	10.1	10.6	10.9	11.0	10.7	10.8	14.7	16.7	20.5	22.2	21.5	18.2	4.8
Percentage of Assets	1.6	1.8	1.7	2.0	2.1	2.1	2.3	2.2	2.2	2.2	2.2	2.5	2.3	1.9	1.3	1.4	1.4	1.5	1.6	1.7	1.8	1.8	2.3	2.5	3.1	3.4	3.2	2.7	1.9
Percentage of Assets country:US	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

lfus:OtherCountries

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2011-12-31
Value	34	35	37	34	35	35	37	37	38	44	45	49	54	65	47	47	46	44	118	45	119	115	90	84	45	73	70	62	59	55	52	51	117	114	98
Percentage of NoncurrentAssets	9.7	10.2	10.8	10.2	10.6	10.6	10.8	11.4	11.4	13.0	13.5	14.4	16.0	19.4	18.8	19.6	20.1	19.8	54.4	20.4	53.1	50.1	55.9	51.6	27.5	45.8	44.5	41.7	41.0	39.5	43.5	16.9	39.0	39.6	35.4
Percentage of Assets	1.2	1.3	1.3	1.3	1.4	1.4	1.5	1.5	1.5	1.7	1.8	1.9	2.1	2.5	2.7	2.8	2.9	2.9	7.9	3.1	8.9	8.2	8.5	7.7	4.2	7.0	6.6	6.1	5.9	5.8	6.6	6.6	15.4	15.8	14.6
Percentage of Assets lfus:OtherCountries	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

Property Plant And Equipment Gross

us-gaap:PropertyPlantAndEquipmentGross us-gaap:PropertyPlantAndEquipmentByType

us-gaap:PropertyPlantAndEquipmentGross

us-gaap:Building

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2017-12-30
Value	128	124	123	122	118	105	108	106	106	114	114	86
Percentage of PropertyPlantAndEquipmentGross	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	4.4	4.5	4.5	4.6	4.5	4.0	4.2	4.2	4.1	4.4	4.4	5.0
Percentage of Assets us-gaap:Building	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

us-gaap:Equipment

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2017-12-30
Value	706	687	678	656	635	633	631	605	612	599	583	505
Percentage of PropertyPlantAndEquipmentGross	549.4	553.6	549.2	534.3	536.8	603.3	581.8	571.3	572.7	523.3	508.6	584.1
Percentage of Assets	24.1	24.7	24.7	24.7	24.3	24.3	24.7	23.8	23.4	22.8	22.3	29.1
Percentage of Assets us-gaap:Equipment	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

us-gaap:Land

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2017-12-30
Value	21	22	22	23	23	22	24	24	24	25	25	9.547
Percentage of PropertyPlantAndEquipmentGross	17.0	18.3	18.5	19.1	19.5	21.7	22.8	23.3	23.3	22.4	22.4	11.0
Percentage of Assets	0.7	0.8	0.8	0.9	0.9	0.9	1.0	1.0	1.0	1.0	1.0	0.5
Percentage of Assets us-gaap:Land	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

Accumulated Depreciation Depletion And Amortization Property Plant And Equipment

us-gaap:AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-01-01
Value	503	489	480	463	442	426	419	406	406	397	383	374	367	366	351	344	333	322	312	309	324	305	296	290	291	287	281	278	277	270	268	275	268	251	244	245	238	227	220	215	212	205
Percentage of AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	17.2	17.6	17.5	17.4	16.9	16.3	16.4	15.9	15.5	15.1	14.7	14.1	14.2	13.9	20.2	20.2	20.6	20.9	20.9	21.2	24.2	21.8	27.8	26.6	26.5	27.1	26.3	24.6	24.6	24.6	26.2	27.4	28.0	31.9	31.5	32.1	32.9	31.8	32.5	31.3	30.4	33.0

Amortization Of Intangible Assets

us-gaap:AmortizationOfIntangibleAssets

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
Value	10	10	10	10	9.827	9.981	9.958	9.827	10	10	13	13	13	11	6.293	6.292	6.171	5.944	5.953	4.432	5.156	3.796	2.923	2.977	3.053	3.05	3.154	3.138	3.159	3.03	2.747	1.93	1.572	1.632	1.599	1.39	1.468	1.831	1.585	1.6	1.595	1.273	1.247	1.265
Percentage of AmortizationOfIntangibleAssets	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

Property Plant And Equipment Net

us-gaap:PropertyPlantAndEquipmentNet

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-01-01
Value	352	344	344	339	334	334	344	329	338	342	339	343	338	337	250	244	232	223	217	223	224	230	162	162	166	160	158	157	158	158	150	146	141	120	120	118	116	116	118	120	127	130
Percentage of PropertyPlantAndEquipmentNet	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	12.1	12.4	12.5	12.8	12.8	12.8	13.5	12.9	12.9	13.0	13.0	12.9	13.1	12.8	14.4	14.4	14.3	14.5	14.6	15.4	16.7	16.4	15.3	14.9	15.1	15.2	14.8	13.9	14.1	14.5	14.7	14.5	14.7	15.3	15.5	15.5	16.0	16.3	17.5	17.5	18.3	21.0

Long Term Investments

us-gaap:LongTermInvestments

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2016-12-31
Value	39	37	30	26	23	21	24	26	25	24	25	29	31	31	10	13
Percentage of LongTermInvestments	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	1.3	1.3	1.1	1.0	0.9	0.8	0.9	1.0	1.0	0.9	1.0	1.1	1.2	1.2	0.6	0.9

Goodwill

us-gaap:Goodwill

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-01-01
Value	851	845	816	799	787	812	820	813	826	825	826	830	832	840	453	451	432	428	403	409	363	312	189	190	192	190	196	198	201	199	186	186	185	131	133	133	131	116	115	119	113	112
Percentage of Goodwill	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	29.1	30.3	29.7	30.1	30.2	31.1	32.1	31.9	31.5	31.4	31.6	31.2	32.2	32.0	26.1	26.5	26.6	27.7	27.1	28.1	27.1	22.2	17.8	17.4	17.6	18.0	18.3	17.5	17.9	18.2	18.2	18.5	19.3	16.7	17.2	17.5	18.2	16.3	17.1	17.4	16.2	18.1

us-gaap:Goodwill us-gaap:BusinessAcquisition

lfus:HartlandControls

Period End	2021-01-28
Value	38
Percentage of Goodwill	0.0
Percentage of Assets	0.0
Percentage of Assets lfus:HartlandControls	0.0

us-gaap:Goodwill us-gaap:FairValueByFairValueHierarchyLevel, us-gaap:FairValueByMeasurementBasis, us-gaap:FairValueByMeasurementFrequency

us-gaap:FairValueInputsLevel3, us-gaap:CarryingReportedAmountFairValueDisclosure, us-gaap:FairValueMeasurementsNonrecurring

Period End	2020-12-26	2020-09-26	2020-06-27
Value	9.832	9.449	9.142
Percentage of Goodwill	1.2	1.2	1.2
Percentage of Assets	0.4	0.4	0.4
Percentage of Assets us-gaap:FairValueInputsLevel3 us-gaap:CarryingReportedAmountFairValueDisclosure us-gaap:FairValueMeasurementsNonrecurring	0.0	0.0	0.0

us-gaap:Goodwill us-gaap:ReportingUnit

lfus:AutomotiveSensors

Period End	2021-06-26	2020-12-26	2020-09-26	2020-06-27
Value	9.6	9.8	9.4	9.1
Percentage of Goodwill	1.1	1.2	1.2	1.2
Percentage of Assets	0.3	0.4	0.4	0.3
Percentage of Assets lfus:AutomotiveSensors	0.0	0.0	0.0	0.0

us-gaap:Goodwill us-gaap:StatementBusinessSegments

lfus:Automotive

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31	2011-01-01
Value	101	99	97	129	131	129	132	132	132	133	134	139	135	144	80	81	84	56	39	41
Percentage of Goodwill	12.5	12.4	12.4	15.9	16.0	16.0	16.0	16.0	16.0	16.1	16.1	16.5	30.0	35.8	42.3	41.6	45.6	42.1	33.9	36.7
Percentage of Assets	3.7	3.7	3.7	5.0	5.1	5.1	5.1	5.0	5.1	5.0	5.2	5.3	7.8	9.7	7.5	7.6	8.3	7.2	5.8	6.7
Percentage of Assets lfus:Automotive	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

lfus:AutomotiveSegment

Period End	2021-06-26	2021-03-27	2020-12-26
Value	100	99	101
Percentage of Goodwill	11.8	11.8	12.5
Percentage of Assets	3.4	3.6	3.7
Percentage of Assets lfus:AutomotiveSegment	0.0	0.0	0.0

lfus:Electronics

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31	2011-01-01	2010-01-02
Value	676	661	651	644	650	645	655	654	656	658	659	663	278	215	58	60	60	60	35	34	35
Percentage of Goodwill	82.8	82.8	82.7	79.3	79.3	79.3	79.3	79.3	79.4	79.3	79.3	78.9	61.5	53.5	30.7	30.8	32.4	45.2	30.6	31.0	0.0
Percentage of Assets	24.6	24.9	25.0	24.7	25.4	25.3	25.0	24.9	25.1	24.7	25.5	25.2	16.0	14.5	5.5	5.7	5.9	7.8	5.2	5.6	0.0
Percentage of Assets lfus:Electronics	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

lfus:ElectronicsSegment

Period End	2021-06-26	2021-03-27	2020-12-26
Value	671	668	676
Percentage of Goodwill	78.9	79.0	82.8
Percentage of Assets	22.9	24.0	24.6
Percentage of Assets lfus:ElectronicsSegment	0.0	0.0	0.0

lfus:Industrial

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28
Value	38	38	38	38	38	38	38	38	38	38	38	38	38	43	51	54	41
Percentage of Goodwill	4.7	4.8	4.9	4.7	4.7	4.7	4.7	4.7	4.6	4.6	4.6	4.6	8.5	10.7	27.0	27.5	22.0
Percentage of Assets	1.4	1.4	1.5	1.5	1.5	1.5	1.5	1.5	1.5	1.4	1.5	1.5	2.2	2.9	4.8	5.0	4.0
Percentage of Assets lfus:Industrial	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

lfus:IndustrialSegment

Period End	2021-06-26	2021-03-27	2020-12-26
Value	79	77	38
Percentage of Goodwill	9.3	9.2	4.7
Percentage of Assets	2.7	2.8	1.4
Percentage of Assets lfus:IndustrialSegment	0.0	0.0	0.0

Intangible Assets Net Excluding Goodwill

us-gaap:IntangibleAssetsNetExcludingGoodwill

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2016-12-31
Value	307	317	291	296	301	308	321	326	341	350	361	377	390	405	203	213
Percentage of IntangibleAssetsNetExcludingGoodwill	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	10.5	11.4	10.6	11.2	11.6	11.8	12.5	12.8	13.0	13.3	13.8	14.2	15.1	15.4	11.7	14.3

Finite Lived Intangible Assets Net

us-gaap:FiniteLivedIntangibleAssetsNet

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2016-12-31
Value	307	317	291	296	301	308	321	326	341	350	361	377	390	405	203	213
Percentage of FiniteLivedIntangibleAssetsNet	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	10.5	11.4	10.6	11.2	11.6	11.8	12.5	12.8	13.0	13.3	13.8	14.2	15.1	15.4	11.7	14.3

us-gaap:FiniteLivedIntangibleAssetsNet us-gaap:FiniteLivedIntangibleAssetsByMajorClass

lfus:CustomerListsTrademarksAndTradeNames

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2016-12-31
Value	249	256	234	237	240	245	253	259	268	274	282	242	248	254	109	110
Percentage of FiniteLivedIntangibleAssetsNet	81.2	80.9	80.3	80.1	79.8	79.5	79.0	79.4	78.8	78.5	78.1	64.4	63.6	62.9	53.5	51.8
Percentage of Assets	8.5	9.2	8.5	8.9	9.2	9.4	9.9	10.2	10.3	10.5	10.8	9.1	9.6	9.7	6.3	7.4
Percentage of Assets lfus:CustomerListsTrademarksAndTradeNames	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

lfus:PatentsLicensesAndSoftware

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2016-12-31
Value	45	48	44	45	47	48	52	59	64	66	69	120	124	129	81	83
Percentage of FiniteLivedIntangibleAssetsNet	14.9	15.2	15.2	15.4	15.6	15.8	16.3	18.3	18.8	19.0	19.4	32.0	32.0	32.0	40.2	39.2
Percentage of Assets	1.6	1.7	1.6	1.7	1.8	1.9	2.0	2.3	2.5	2.5	2.7	4.5	4.8	4.9	4.7	5.6
Percentage of Assets lfus:PatentsLicensesAndSoftware	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

us-gaap:DistributionRights

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2016-12-31
Value	3.821	4.397	4.93	5.44	5.97	6.516	7.076	7.624	8.198	8.748	9.312	9.884	10	11	12	18
Percentage of FiniteLivedIntangibleAssetsNet	1.2	1.4	1.7	1.8	2.0	2.1	2.2	2.3	2.4	2.5	2.6	2.6	2.7	2.7	6.3	8.9
Percentage of Assets	0.1	0.2	0.2	0.2	0.2	0.2	0.3	0.3	0.3	0.3	0.4	0.4	0.4	0.4	0.7	1.3
Percentage of Assets us-gaap:DistributionRights	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

us-gaap:UseRights

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2018-12-29
Value	8.215	8.2	8.273	8.018	7.784	7.79	7.919	5.624
Percentage of FiniteLivedIntangibleAssetsNet	2.7	2.6	2.8	2.7	2.6	2.5	2.5	1.6
Percentage of Assets	0.3	0.3	0.3	0.3	0.3	0.3	0.3	0.2
Percentage of Assets us-gaap:UseRights	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

Operating Lease Right Of Use Asset

us-gaap:OperatingLeaseRightOfUseAsset

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29
Value	28	19	17	18	19	20	21	21	23	24	0.0
Percentage of OperatingLeaseRightOfUseAsset	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	0.0
Percentage of Assets	1.0	0.7	0.6	0.7	0.8	0.8	0.9	0.8	0.9	0.9	0.0

Other Assets Noncurrent

us-gaap:OtherAssetsNoncurrent

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-01-01
Value	19	19	18	17	17	14	14	18	18	18	20	21	27	28	17	8.913	10	10	10	12	18	23	14	16	19	22	23	6.75	7.065	7.229	6.402	4.893	4.162	1.878	1.865	2.186	2.136	1.852	1.82	2.368	2.797	2.58
Percentage of OtherAssetsNoncurrent	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	0.7	0.7	0.7	0.7	0.7	0.6	0.6	0.7	0.7	0.7	0.8	0.8	1.0	1.1	1.0	0.5	0.7	0.7	0.7	0.9	1.4	1.6	1.3	1.5	1.8	2.2	2.2	0.6	0.6	0.7	0.6	0.5	0.4	0.2	0.2	0.3	0.3	0.3	0.3	0.3	0.4	0.4

Equity Securities Fv Ni

us-gaap:EquitySecuritiesFvNi

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30
Value	27	25	19	15	12	10	12	12	11	10	10	12	15	14	10
Percentage of EquitySecuritiesFvNi	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	0.9	0.9	0.7	0.6	0.5	0.4	0.5	0.5	0.4	0.4	0.4	0.5	0.6	0.6	0.6

us-gaap:EquitySecuritiesFvNi us-gaap:BalanceSheetLocation

us-gaap:OtherAssets

Period End	2020-12-26	2019-12-28
Value	0.5	0.4
Percentage of EquitySecuritiesFvNi	2.6	3.1
Percentage of Assets	0.0	0.0
Percentage of Assets us-gaap:OtherAssets	0.0	0.0

us-gaap:EquitySecuritiesFvNi us-gaap:FairValueByFairValueHierarchyLevel

us-gaap:FairValueInputsLevel1

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30
Value	27	25	19	15	12	10	12	12	11	10	10	12	15	14	10
Percentage of EquitySecuritiesFvNi	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	0.9	0.9	0.7	0.6	0.5	0.4	0.5	0.5	0.4	0.4	0.4	0.5	0.6	0.6	0.6
Percentage of Assets us-gaap:FairValueInputsLevel1	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

us-gaap:EquitySecuritiesFvNi us-gaap:IncomeStatementLocation

lfus:OtherExpenseIncome

Period End	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30
Value	0.5	0.5	0.5	0.4	0.4	0.4	1.2	1.2	1.2
Percentage of EquitySecuritiesFvNi	1.9	2.6	3.3	3.1	3.8	3.1	9.5	10.8	11.4
Percentage of Assets	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
Percentage of Assets lfus:OtherExpenseIncome	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

us-gaap:EquitySecuritiesFvNi us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

lfus:Polytronics

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	15	11	10	11
Percentage of EquitySecuritiesFvNi	81.8	89.4	98.9	100.1
Percentage of Assets	0.6	0.5	0.4	0.6
Percentage of Assets lfus:Polytronics	0.0	0.0	0.0	0.0

Accounts Payable Current

us-gaap:AccountsPayableCurrent

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-01-01
Value	205	179	145	120	113	106	117	107	123	129	126	129	127	120	101	103	100	88	90	81	78	73	51	53	53	47	50	37	36	37	33	38	36	29	27	27	28	28	19	26	30	24
Percentage of AccountsPayableCurrent	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	7.0	6.4	5.3	4.6	4.4	4.1	4.6	4.2	4.7	4.9	4.8	4.9	4.9	4.6	5.9	6.1	6.2	5.7	6.1	5.6	5.8	5.2	4.9	4.9	4.9	4.5	4.7	3.3	3.3	3.4	3.3	3.9	3.8	3.8	3.5	3.6	3.9	4.0	2.9	3.8	4.4	3.9

Accrued Income Taxes Current

us-gaap:AccruedIncomeTaxesCurrent

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-01-01
Value	25	23	19	15	10	17	14	16	21	23	20	36	19	15	16	16	9.522	8.827	8.846	8.622	6.682	9.929	10	6.738	8.547	9.893	9.045	15	6.422	7.357	5.931	10	6.226	8.196	11	12	11	13	10	19	18	14
Percentage of AccruedIncomeTaxesCurrent	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	0.9	0.8	0.7	0.6	0.4	0.7	0.6	0.7	0.8	0.9	0.8	1.4	0.7	0.6	0.9	1.0	0.6	0.6	0.6	0.6	0.5	0.7	1.0	0.6	0.8	0.9	0.8	1.3	0.6	0.7	0.6	1.0	0.6	1.0	1.5	1.7	1.6	1.8	1.6	2.9	2.6	2.4

Accrued Liabilities Current

us-gaap:AccruedLiabilitiesCurrent

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-01-01
Value	126	98	110	98	85	73	84	114	111	107	138	74	66	74	48	52	50	47	36	48	55	40	24	20	19	12	13	13	13	13	13	11	11	9.703	11	10	8.294	8.772	8.861	9.191	9.366	10
Percentage of AccruedLiabilitiesCurrent	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	4.3	3.5	4.0	3.7	3.3	2.8	3.3	4.5	4.3	4.1	5.3	2.8	2.6	2.9	2.8	3.1	3.1	3.1	2.4	3.3	4.2	2.9	2.3	1.9	1.8	1.1	1.2	1.2	1.2	1.2	1.3	1.2	1.2	1.2	1.4	1.4	1.1	1.2	1.3	1.3	1.3	1.7

Contract With Customer Liability Current

us-gaap:ContractWithCustomerLiabilityCurrent

Period End	2021-06-26	2021-03-27	2020-12-26
Value	790000.0	794000.0	3858000.0
Percentage of ContractWithCustomerLiabilityCurrent	100.0	100.0	100.0
Percentage of Assets	0.0	0.0	0.1

Liabilities Current

us-gaap:LiabilitiesCurrent

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-01-01
Value	381	326	275	234	209	208	225	248	266	269	295	303	267	264	224	226	202	177	187	187	178	232	209	232	203	190	204	280	283	268	208	221	211	155	155	160	156	164	149	171	148	109
Percentage of LiabilitiesCurrent	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	13.0	11.7	10.0	8.8	8.0	8.0	8.8	9.7	10.2	10.3	11.3	11.4	10.3	10.1	12.9	13.3	12.5	11.5	12.6	12.9	13.3	16.6	19.7	21.3	18.5	17.9	19.1	24.7	25.1	24.5	20.4	22.0	22.1	19.8	20.0	21.0	21.6	22.9	22.0	25.0	21.3	17.7

Long Term Debt Current

us-gaap:LongTermDebtCurrent

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-01-01
Value	25	25	0.0	10.0	10.0	10.0	10.0	10.0	10.0	10	10	10	6.25	9.375	7.813	6.25	6.25	6.25	6.25	6.25	87	117	82	87	88	186	204	193	126	133	138	94	84	88	85	96	85	93	70	33
Percentage of LongTermDebtCurrent	100.0	100.0	0.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	0.9	0.9	0.0	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.4	0.6	0.5	0.4	0.4	0.4	0.5	0.4	8.2	10.8	7.5	8.2	8.3	16.4	18.1	17.6	12.3	13.3	14.4	11.9	10.8	11.6	11.8	13.5	12.5	13.5	10.1	5.3

Operating Lease Liability Current

us-gaap:OperatingLeaseLiabilityCurrent

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29
Value	8853000.0	7177000.0	6811000.0	6866000.0	6846000.0	7073000.0	7259000.0	6926000.0	7349000.0	7447000.0	0
Percentage of OperatingLeaseLiabilityCurrent	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	0.0
Percentage of Assets	0.3	0.3	0.2	0.3	0.3	0.3	0.3	0.3	0.3	0.3	0.0

Other Accrued Liabilities Current

us-gaap:OtherAccruedLiabilitiesCurrent

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2017-12-30	2011-12-31	2011-10-01	2011-07-02	2011-01-01
Value	32	32	29	28	23	22	22	23	24	25	36	27	1.843	1.871	2.142	3.279
Percentage of OtherAccruedLiabilitiesCurrent	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	1.1	1.2	1.1	1.1	0.9	0.8	0.9	0.9	0.9	1.0	1.4	1.6	0.3	0.3	0.3	0.5

Long Term Debt

us-gaap:LongTermDebt

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2012-12-29	2011-12-31
Value	651	648	687	725	776	774	679	678	686	686	694	700	697	753	495	501	481	470	454	440	367	377	171	209	179	189	195	276	295	285	219	228	233	-84.0	-85.0
Percentage of LongTermDebt	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	22.3	23.3	25.0	27.3	29.7	29.6	26.5	26.6	26.2	26.2	26.6	26.3	27.0	28.7	28.5	29.5	29.7	30.5	30.5	30.2	27.4	26.9	16.1	19.1	16.3	17.9	18.2	24.4	26.2	26.1	21.5	22.7	24.3	-10.8	-12.5

Long Term Debt Noncurrent

us-gaap:LongTermDebtNoncurrent

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28
Value	626	623	687	725	776	764	669	668	676	676	684	690	687	743	489	492	473	464	447	434	361	371	84	91	96	102	106	90	91	92	93
Percentage of LongTermDebtNoncurrent	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	21.4	22.4	25.0	27.3	29.7	29.3	26.1	26.2	25.8	25.8	26.2	25.9	26.6	28.3	28.1	28.9	29.2	30.1	30.0	29.8	27.0	26.4	7.9	8.4	8.8	9.7	10.0	7.9	8.1	8.4	9.2

Deferred Income Tax Liabilities Net

us-gaap:DeferredIncomeTaxLiabilitiesNet

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2018-12-29	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-01-02
Value	47	51	50	46	46	49	49	51	53	44	5.211	7.719	8.826	8.539	7.066	7.345	8.014
Percentage of DeferredIncomeTaxLiabilitiesNet	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	1.6	1.8	1.8	1.8	1.8	1.9	1.9	2.0	2.0	1.7	0.3	0.5	0.5	0.6	0.5	0.5	0.8

Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-01-01
Value	43	42	45	40	39	35	38	28	30	31	31	32	33	35	18	16	15	13	13	6.235	7.498	7.481	5.653	5.025	5.247	5.073	5.147	0.225	0.182	8.528	14	14	17	22	10	10	10	15	5.356	5.482	5.564
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	1.5	1.5	1.7	1.5	1.5	1.4	1.5	1.1	1.2	1.2	1.2	1.2	1.3	1.4	1.1	1.0	1.0	0.9	0.9	0.4	0.6	0.5	0.5	0.5	0.5	0.5	0.5	0.0	0.0	0.8	1.5	1.6	2.2	2.9	1.4	1.4	1.5	2.3	0.8	0.8	0.9

Minority Interest

us-gaap:MinorityInterest

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31	2011-01-01
Value	131000.0	131000.0	131000.0	131000.0	131000.0	131000.0	131000.0	131000.0	131000.0	131000.0	131000.0	130000.0	130000.0	137000.0	137000.0	137000.0	143000.0	143000.0	143000.0	143000.0	143000.0	143000.0	143000.0	143000.0	143000.0
Percentage of MinorityInterest	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

Other Liabilities Noncurrent

us-gaap:OtherLiabilitiesNoncurrent

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-01-01
Value	66	67	67	63	61	61	64	64	65	69	72	67	76	81	62	26	25	24	20	19	12	12	12	10	14	15	15	14	14	16	14	15	15	13	12	11	11	12	12	13	14	11
Percentage of OtherLiabilitiesNoncurrent	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	2.3	2.4	2.4	2.4	2.4	2.4	2.5	2.5	2.5	2.6	2.8	2.5	2.9	3.1	3.6	1.5	1.6	1.6	1.4	1.3	0.9	0.9	1.2	1.0	1.4	1.5	1.5	1.3	1.3	1.5	1.5	1.5	1.6	1.8	1.6	1.5	1.6	1.7	1.9	2.0	2.0	1.9

Operating Lease Liability Noncurrent

us-gaap:OperatingLeaseLiabilityNoncurrent

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29
Value	19	14	12	14	15	15	17	17	18	19	0.0
Percentage of OperatingLeaseLiabilityNoncurrent	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	0.0
Percentage of Assets	0.7	0.5	0.5	0.5	0.6	0.6	0.7	0.7	0.7	0.8	0.0

Lessee Operating Lease Liability Payments Due Year Two

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearTwo

Period End	2020-12-26
Value	6162000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	100.0
Percentage of Assets	0.2

Lessee Operating Lease Liability Payments Due Year Three

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearThree

Period End	2020-12-26
Value	3952000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearThree	100.0
Percentage of Assets	0.1

Lessee Operating Lease Liability Payments Due Year Four

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFour

Period End	2020-12-26
Value	3350000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFour	100.0
Percentage of Assets	0.1

Lessee Operating Lease Liability Payments Due Year Five

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueYearFive

Period End	2020-12-26
Value	262000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueYearFive	100.0
Percentage of Assets	0.0

Lessee Operating Lease Liability Payments Due After Year Five

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive

Period End	2020-12-26
Value	302000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	100.0
Percentage of Assets	0.0

Operating Lease Liability

us-gaap:OperatingLeaseLiability

Period End	2020-12-26	2020-03-28	2019-12-28	2019-09-28	2019-06-29
Value	19	23	24	24	25
Percentage of OperatingLeaseLiability	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	0.7	0.9	1.0	0.9	1.0

Lessee Operating Lease Liability Payments Due

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDue

Period End	2020-12-26
Value	21
Percentage of LesseeOperatingLeaseLiabilityPaymentsDue	100.0
Percentage of Assets	0.8

Stockholders Equity

us-gaap:StockholdersEquity

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31	2011-01-01
Value	1742	1660	1608	1529	1462	1476	1495	1472	1509	1505	1478	1519	1469	1441	927	933	895	855	814	744	727	686	587	500	452
Percentage of StockholdersEquity	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	59.5	59.6	58.5	57.6	56.0	56.5	58.4	57.7	57.6	57.3	56.5	57.0	56.8	54.9	53.3	54.8	55.2	55.4	54.6	69.9	67.9	67.0	75.5	73.8	72.9

Stockholders Equity Including Portion Attributable To Noncontrolling Interest

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-01-01	2010-01-02	2008-12-27
Value	1742	1660	1608	1529	1462	1476	1496	1472	1509	1505	1478	1519	1470	1441	927	933	895	855	814	803	774	773	744	733	767	735	727	737	727	706	686	660	622	600	587	580	546	529	501	496	528	452	378	333
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	59.5	59.6	58.6	57.6	56.0	56.5	58.4	57.7	57.6	57.3	56.5	57.0	56.8	54.9	53.3	54.8	55.2	55.4	54.6	55.1	57.7	55.1	69.9	67.2	69.8	69.4	68.0	65.1	64.4	64.5	67.1	65.6	64.9	76.2	75.5	76.1	75.4	73.9	73.9	72.3	75.8	72.9	0.0	0.0

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest us-gaap:StatementEquityComponents

us-gaap:AccumulatedDefinedBenefitPlansAdjustment

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2017-12-30
Value	-33.358	-33.687	-34.141	-27.761	-28.324	-17.485	-18.046	-9.71	-9.847	-10.008	-9.959	-10.188	-10.836
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	-1.9	-2.0	-2.1	-1.8	-1.9	-1.2	-1.2	-0.7	-0.7	-0.7	-0.7	-0.7	-1.2
Percentage of Assets	-1.1	-1.2	-1.2	-1.0	-1.1	-0.7	-0.7	-0.4	-0.4	-0.4	-0.4	-0.4	-0.6
Percentage of Assets us-gaap:AccumulatedDefinedBenefitPlansAdjustment	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

us-gaap:AccumulatedOtherComprehensiveIncome

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31	2011-01-01	2010-01-02	2008-12-27
Value	-90.574	-96.028	-91.157	-107.238	-124.219	-121.802	-106.823	-112.608	-95.582	-89.851	-97.924	-97.631	-89.684	-73.742	-63.668	-74.579	-45.671	-21.126	20	16	8.631	21	18	-10.123
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	-5.2	-5.8	-5.7	-7.0	-8.5	-8.2	-7.1	-7.6	-6.3	-6.0	-6.6	-6.4	-6.1	-5.1	-6.9	-9.2	-6.1	-2.9	3.0	2.8	1.7	4.7	4.9	-3.0
Percentage of Assets	-3.1	-3.4	-3.3	-4.0	-4.8	-4.7	-4.2	-4.4	-3.6	-3.4	-3.7	-3.7	-3.5	-2.8	-3.7	-5.0	-4.3	-2.0	2.0	2.1	1.3	3.4	0.0	0.0
Percentage of Assets us-gaap:AccumulatedOtherComprehensiveIncome	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

us-gaap:AccumulatedTranslationAdjustment

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2017-12-30
Value	-57.216	-62.341	-57.016	-79.477	-95.895	-104.317	-88.777	-102.898	-85.735	-79.843	-87.965	-87.443	-62.627
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	-3.3	-3.8	-3.5	-5.2	-6.6	-7.1	-5.9	-7.0	-5.7	-5.3	-6.0	-5.8	-6.8
Percentage of Assets	-2.0	-2.2	-2.1	-3.0	-3.7	-4.0	-3.5	-4.0	-3.3	-3.0	-3.4	-3.3	-3.6
Percentage of Assets us-gaap:AccumulatedTranslationAdjustment	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

us-gaap:AdditionalPaidInCapital

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31	2011-01-01	2010-01-02	2008-12-27
Value	930	918	907	891	885	874	867	860	855	842	835	830	815	800	310	291	259	243	223	195	174	150	130	124
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	53.4	55.3	56.4	58.3	60.5	59.2	58.0	58.5	56.6	55.9	56.5	54.7	55.5	55.5	33.4	35.7	34.9	33.5	32.5	33.3	34.8	33.3	34.6	37.3
Percentage of Assets	31.8	33.0	33.0	33.6	33.9	33.5	33.9	33.7	32.6	32.1	32.0	31.2	31.5	30.5	17.8	19.5	24.4	22.8	21.8	25.2	25.7	24.2	0.0	0.0
Percentage of Assets us-gaap:AdditionalPaidInCapital	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

us-gaap:CommonStock

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31	2011-01-01	2010-01-02	2008-12-27
Value	0.26	0.259	0.259	0.258	0.257	0.256	0.256	0.256	0.255	0.254	0.254	0.254	0.253	0.251	0.229	0.228	0.224	0.226	0.225	0.22	0.216	0.218	0.218	0.217
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.1	0.1
Percentage of Assets	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
Percentage of Assets us-gaap:CommonStock	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

us-gaap:NoncontrollingInterest

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31	2011-01-01	2010-01-02	2008-12-27
Value	0.131	0.131	0.131	0.131	0.131	0.131	0.131	0.131	0.131	0.131	0.131	0.13	0.13	0.137	0.137	0.143	0.143	0.143	0.143	0.143	0.143	0.143	0.143	0.143
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
Percentage of Assets	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
Percentage of Assets us-gaap:NoncontrollingInterest	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

us-gaap:RetainedEarnings

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31	2011-01-01	2010-01-02	2008-12-27
Value	1150	1079	1034	986	943	963	950	939	916	882	856	834	791	758	722	634	562	523	445	435	376	304	228	219
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	66.0	65.0	64.3	64.5	64.5	65.3	63.6	63.8	60.7	58.6	57.9	54.9	53.9	52.6	77.9	77.8	75.6	71.9	64.8	74.1	75.1	67.2	60.4	65.7
Percentage of Assets	39.3	38.8	37.6	37.2	36.1	36.9	37.1	36.8	34.9	33.6	32.8	31.3	30.6	28.9	41.5	42.5	52.8	48.9	43.4	56.0	55.5	49.0	0.0	0.0
Percentage of Assets us-gaap:RetainedEarnings	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

us-gaap:TreasuryStock

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31	2011-01-01
Value	-247.963	-242.366	-242.366	-242.323	-242.192	-239.817	-216.447	-216.384	-166.068	-130.103	-116.454	-48.546	-48.336	-44.052	-41.294	-36.51	-32.766	-18.724	-2.353	-60.496	-58.834	-23.546
Percentage of StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	-14.2	-14.6	-15.1	-15.8	-16.6	-16.2	-14.5	-14.7	-11.0	-8.6	-7.9	-3.2	-3.3	-3.1	-4.5	-4.5	-4.4	-2.6	-0.3	-10.3	-11.7	-5.2
Percentage of Assets	-8.5	-8.7	-8.8	-9.1	-9.3	-9.2	-8.5	-8.5	-6.3	-5.0	-4.5	-1.8	-1.9	-1.7	-2.4	-2.4	-3.1	-1.7	-0.2	-7.8	-8.7	-3.8
Percentage of Assets us-gaap:TreasuryStock	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

Common Stock Value

us-gaap:CommonStockValue

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31	2011-01-01
Value	260000.0	259000.0	259000.0	258000.0	257000.0	256000.0	256000.0	256000.0	255000.0	254000.0	254000.0	254000.0	253000.0	251000.0	229000.0	229000.0	245000.0	228000.0	228000.0	224000.0	226000.0	225000.0	220000.0	216000.0	218000.0
Percentage of CommonStockValue	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

Additional Paid In Capital

us-gaap:AdditionalPaidInCapital

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31
Value	930	918	907	891	885	874	867	860	855	842	835	830	815	800	310	306	302	295	291	259	243	223	195	174
Percentage of AdditionalPaidInCapital	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	31.8	33.0	33.0	33.6	33.9	33.5	33.9	33.7	32.6	32.1	32.0	31.2	31.5	30.5	17.8	18.0	18.6	19.1	19.5	24.4	22.8	21.8	25.2	25.7

Retained Earnings Accumulated Deficit

us-gaap:RetainedEarningsAccumulatedDeficit

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31	2011-01-01
Value	1150	1079	1034	986	943	963	950	939	916	882	856	834	791	758	722	741	706	665	634	562	523	445	435	376	304
Percentage of RetainedEarningsAccumulatedDeficit	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	39.3	38.8	37.6	37.2	36.1	36.9	37.1	36.8	34.9	33.6	32.8	31.3	30.6	28.9	41.5	43.6	43.6	43.1	42.5	52.8	48.9	43.4	56.0	55.5	49.0

Accumulated Other Comprehensive Income Loss Net Of Tax

us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2011-12-31	2011-01-01
Value	-90.574	-96.028	-91.157	-107.238	-124.219	-121.802	-106.823	-112.608	-95.582	-89.851	-97.924	-97.631	-89.684	-73.742	-63.668	-73.343	-73.104	-68.952	-74.579	-55.152	-50.238	-34.985	-45.671	-35.233	-26.096	-32.084	-21.126	6.954	23	14	20	13	4.03	12	16	19	9.492	8.631	21
Percentage of AccumulatedOtherComprehensiveIncomeLossNetOfTax	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	-3.1	-3.4	-3.3	-4.0	-4.8	-4.7	-4.2	-4.4	-3.6	-3.4	-3.7	-3.7	-3.5	-2.8	-3.7	-4.3	-4.5	-4.5	-5.0	-3.8	-3.7	-2.5	-4.3	-3.2	-2.4	-3.0	-2.0	0.6	2.1	1.3	2.0	1.4	0.4	1.6	2.1	2.6	1.3	1.3	3.4

Treasury Stock Value

us-gaap:TreasuryStockValue

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31	2011-01-01
Value	247	242	242	242	242	239	216	216	166	130	116	48	48	44	41	41	41	36	36	32	18	2.353	60	58	23
Percentage of TreasuryStockValue	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	8.5	8.7	8.8	9.1	9.3	9.2	8.5	8.5	6.3	5.0	4.5	1.8	1.9	1.7	2.4	2.4	2.5	2.4	2.4	3.1	1.7	0.2	7.8	8.7	3.8

Minority Interest

us-gaap:MinorityInterest

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31	2011-01-01
Value	131000.0	131000.0	131000.0	131000.0	131000.0	131000.0	131000.0	131000.0	131000.0	131000.0	131000.0	130000.0	130000.0	137000.0	137000.0	137000.0	143000.0	143000.0	143000.0	143000.0	143000.0	143000.0	143000.0	143000.0	143000.0
Percentage of MinorityInterest	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue

Period End	2021-06-26	2021-03-27	2020-09-26	2020-06-27	2020-03-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	8.843	3.395	3.692	7.887	2.965	3.488	8.284	3.966	4.278	7.27	7.169	8.714
Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

us-gaap:AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital

Period End	2021-06-26	2021-03-27	2020-09-26	2020-06-27	2020-03-28	2019-09-28	2019-06-29	2019-03-30	2018-09-29	2018-06-30	2018-03-31
Value	8.843	3.395	3.692	7.887	2.965	3.488	8.284	3.966	7.27	7.169	8.714
Percentage of AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of Assets	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
Percentage of Assets us-gaap:AdditionalPaidInCapital	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-04-02	2011-01-01	2010-10-02
Value	76	50	93	62	56	45	84	80	49	30	79	111	71	69	87	87	70	22	80	64	25	9.492	51	38	23	49	61	31	11	31	46	22	16	40	43	24	7.864	36	37	13	29	48
Percentage of NetCashProvidedByUsedInOperatingActivities	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	14.6	10.8	23.4	16.1	18.2	13.1	25.0	22.3	12.4	7.6	19.8	25.3	15.6	16.6	28.8	27.6	22.5	8.0	28.2	23.1	9.5	4.3	24.0	17.4	11.0	23.9	28.2	14.0	5.6	15.9	23.3	12.2	9.4	25.3	25.2	14.1	4.9	25.0	21.8	8.2	20.4	29.9

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-04-02	2011-01-01	2010-10-02
Value	-17920000.0	-122020000.0	-10045000.0	-11998000.0	-12854000.0	-16536000.0	-23497000.0	-13148000.0	-5568000.0	-14244000.0	-13685000.0	-17829000.0	-26357000.0	-324380000.0	-16936000.0	-43084000.0	-14019000.0	-22098000.0	-12762000.0	-124280000.0	-100980000.0	-273220000.0	-6227000.0	-10548000.0	-12273000.0	-38645000.0	515000.0	-7455000.0	-58408000.0	-6945000.0	-10781000.0	-153940000.0	-13922000.0	-8563000.0	-11087000.0	-24203000.0	-7839000.0	-22759000.0	-15628000.0	-4447000.0	-54736000.0	-8551000.0
Percentage of NetCashProvidedByUsedInInvestingActivities	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	-3.4	-26.3	-2.5	-3.1	-4.2	-4.8	-6.9	-3.6	-1.4	-3.5	-3.4	-4.1	-5.7	-77.6	-5.6	-13.6	-4.5	-7.7	-4.5	-44.3	-37.1	-124.5	-2.9	-4.8	-5.8	-18.7	0.2	-3.4	-28.2	-3.5	-5.4	-82.0	-8.1	-5.4	-6.4	-13.8	-4.9	-15.5	-9.0	-2.7	-38.4	-5.2

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-04-02	2011-01-01	2010-10-02
Value	-14.91	-34.273	-49.432	-68.902	-15.278	65	-10.811	-59.841	-44.291	-31.333	-73.362	-0.948	-44.101	240	-18.19	3.588	-13.017	2.938	21	73	-14.946	203	-7.543	-11.164	-8.445	-84.716	-23.056	-0.912	65	-10.768	-5.222	146	11	-5.702	1.814	-7.666	12	-10.231	-16.858	8.689	17	-15.194
Percentage of NetCashProvidedByUsedInFinancingActivities	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	-2.8	-7.4	-12.3	-17.6	-5.0	19.0	-3.2	-16.5	-11.1	-7.7	-18.2	-0.2	-9.6	57.5	-6.0	1.1	-4.2	1.0	7.7	26.3	-5.5	92.9	-3.5	-5.0	-4.0	-41.0	-10.6	-0.4	31.6	-5.4	-2.6	78.2	6.6	-3.6	1.1	-4.4	7.7	-7.0	-9.7	5.2	12.3	-9.3

Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect

us-gaap:CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29
Value	44	-110.228	45	-9.977	31	89	55	1.276	-1.833	-13.119	-8.482
Percentage of CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	8.5	-23.8	11.4	-2.5	10.2	25.8	16.3	0.4	-0.5	-3.2	-2.1

Deferred Income Tax Expense Benefit

us-gaap:DeferredIncomeTaxExpenseBenefit

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01
Value	-2.55	0.378	-4.781	-0.945	1.896	0.616	-0.944	0.429	-0.56	-0.072	6.3	-13.413	1.592	0.842	15	0.349	0.898	0.616
Percentage of DeferredIncomeTaxExpenseBenefit	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

Depreciation Depletion And Amortization

us-gaap:DepreciationDepletionAndAmortization

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02
Value	24	24	24	24	23	23	23	23	22	23	27	26	26	23	16	15	15	15	14	13	14	11	10	10	10	10	10	10	10	8.628	9.601	8.447	7.804	7.947	7.947	7.969	7.566	7.949	8.442	8.305	7.915
Percentage of DepreciationDepletionAndAmortization	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:DepreciationDepletionAndAmortization us-gaap:StatementBusinessSegments

lfus:Automotive

Period End	2020-09-26	2020-06-27	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02
Value	7.37	7.071	7.074	7.067	6.904	6.877	5.503	5.891	5.969	5.97	5.887	5.622	5.58	5.371	5.226	4.627	4.988	3.266	3.244	3.303	3.336	3.595	3.435	3.646	3.528	2.745	2.88	2.319	1.984	1.96	1.96	1.911	1.502	1.449	1.511	1.442	1.624
Percentage of DepreciationDepletionAndAmortization	30.3	29.8	30.2	30.6	30.4	29.5	20.3	22.4	22.8	25.3	35.9	35.3	35.7	35.6	35.0	35.3	35.4	29.6	31.4	31.8	32.0	33.6	32.9	34.4	34.7	31.8	30.0	27.5	25.4	24.7	24.7	24.0	19.9	18.2	17.9	17.4	20.5

lfus:AutomotiveSegment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	6.946	7.073	7.071	7.187
Percentage of DepreciationDepletionAndAmortization	28.7	29.2	29.8	30.2

lfus:Electronics

Period End	2020-09-26	2020-06-27	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02
Value	15	15	15	14	14	15	16	15	15	13	9.135	8.986	8.707	8.387	8.358	7.694	7.717	5.372	5.811	5.775	5.798	5.695	5.582	5.53	5.37	4.959	5.784	5.131	4.861	5.028	5.028	5.115	5.112	5.486	5.708	5.94	5.394
Percentage of DepreciationDepletionAndAmortization	65.0	65.8	65.3	64.8	64.9	65.9	61.0	60.5	59.8	57.9	55.8	56.4	55.8	55.6	56.0	58.7	54.8	48.7	56.3	55.7	55.7	53.3	53.5	52.2	52.8	57.5	60.2	60.7	62.3	63.3	63.3	64.2	67.6	69.0	67.6	71.5	68.1

lfus:ElectronicsSegment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	15	15	15	15
Percentage of DepreciationDepletionAndAmortization	62.4	63.6	65.8	65.3

lfus:Industrial

Period End	2020-09-26	2020-06-27	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28
Value	1.14	1.046	1.059	1.061	1.056	1.06	1.37	1.364	1.467	1.46	1.355	1.338	1.33	1.314	1.328	1.733	1.376	1.451	1.26	1.295	1.284
Percentage of DepreciationDepletionAndAmortization	4.7	4.4	4.5	4.6	4.7	4.6	5.0	5.2	5.6	6.2	8.3	8.4	8.5	8.7	8.9	13.2	9.8	13.2	12.2	12.5	12.3

lfus:IndustrialSegment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	2.155	1.744	1.046	1.084
Percentage of DepreciationDepletionAndAmortization	8.9	7.2	4.4	4.6

Increase Decrease In Accounts Payable

us-gaap:IncreaseDecreaseInAccountsPayable

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-04-02	2011-01-01	2010-10-02
Value	21	17	22	3.222	7.403	-3.964	6.879	-11.526	-9.428	-8.499	-3.325	3.349	10	2.99	-2.954	1.463	11	-3.295	11	4.871	-0.742	3.716	0.776	6.403	-2.963	14	0.491	-0.523	3.056	-4.659	2.004	2.203	2.452	-0.287	-1.533	-1.379	8.552	-6.295	-4.828	3.904	-4.815	-1.921
Percentage of IncreaseDecreaseInAccountsPayable	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

Increase Decrease In Accounts Receivable

us-gaap:IncreaseDecreaseInAccountsReceivable

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-04-02	2011-01-01	2010-10-02
Value	36	32	-3.774	43	-23.371	9.457	-25.716	-16.023	7.442	5.8	-17.049	-12.893	25	8.417	-15.705	-5.247	20	11	0.373	4.016	10	10	-2.992	17	3.91	3.334	-8.143	11	6.503	0.335	-3.898	10	9.745	-11.169	34	-7.662	-14.017	17	6.62	-11.279	15	2.182
Percentage of IncreaseDecreaseInAccountsReceivable	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

Increase Decrease In Inventories

us-gaap:IncreaseDecreaseInInventories

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-04-02	2011-01-01	2010-10-02
Value	32	6.152	10	-9.15	17	-6.667	-3.992	-11.872	-9.48	3.25	16	16	1.233	0.269	3.021	8.42	5.443	3.296	-4.034	-5.787	-2.202	3.484	3.004	1.348	-0.149	-1.86	4.528	-1.184	0.774	0.949	7.891	0.278	-3.632	-5.381	2.092	-0.437	-1.713	6.982	-2.895	0.675	-2.288	-3.679
Percentage of IncreaseDecreaseInInventories	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

Net Cash Provided By Used In Operating Activities

us-gaap:NetCashProvidedByUsedInOperatingActivities

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-04-02	2011-01-01	2010-10-02
Value	76	50	93	62	56	45	84	80	49	30	79	111	71	69	87	87	70	22	80	64	25	9.492	51	38	23	49	61	31	11	31	46	22	16	40	43	24	7.864	36	37	13	29	48
Percentage of NetCashProvidedByUsedInOperatingActivities	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	14.6	10.8	23.4	16.1	18.2	13.1	25.0	22.3	12.4	7.6	19.8	25.3	15.6	16.6	28.8	27.6	22.5	8.0	28.2	23.1	9.5	4.3	24.0	17.4	11.0	23.9	28.2	14.0	5.6	15.9	23.3	12.2	9.4	25.3	25.2	14.1	4.9	25.0	21.8	8.2	20.4	29.9

Profit Loss

us-gaap:ProfitLoss

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-04-02	2011-01-01	2010-10-02	2010-07-03
Value	82	57	58	55	-8.991	24	22	35	43	36	32	53	42	36	-10.819	42	48	38	27	30	27	19	22	11	28	19	19	29	24	25	23	26	26	14	9.841	23	23	17	15	24	25	21	19	23	20
Percentage of ProfitLoss	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	15.7	12.4	14.7	14.1	-2.9	7.1	6.7	9.8	11.0	9.1	8.1	12.2	9.2	8.6	-3.5	13.5	15.5	13.6	9.6	11.0	10.0	8.8	10.2	5.3	12.9	9.5	9.4	13.8	11.1	12.3	11.9	13.4	14.2	8.7	6.2	13.9	13.4	11.1	10.4	14.3	14.3	12.9	13.7	14.3	12.9

us-gaap:ProfitLoss us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings

Period End	2021-06-26	2021-03-27	2020-09-26	2020-06-27	2020-03-28	2019-09-28	2019-06-29	2019-03-30	2018-09-29	2018-06-30	2018-03-31
Value	82	57	55	-8.991	24	35	43	36	53	42	36
Percentage of ProfitLoss	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	15.7	12.4	14.1	-2.9	7.1	9.8	11.0	9.1	12.2	9.2	8.6
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax us-gaap:RetainedEarnings	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0

Share Based Compensation

us-gaap:ShareBasedCompensation

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-04-02	2011-01-01	2010-10-02
Value	8.843	3.395	3.585	3.692	7.887	2.965	3.308	3.488	8.284	3.966	4.278	7.27	7.169	8.714	3.878	3.847	5.007	3.583	2.821	3.042	3.92	2.204	2.233	3.962	1.802	1.901	1.939	3.764	1.465	1.579	2.468	2.783	1.779	1.774	1.849	2.36	1.365	1.304	1.461	1.182	1.2	1.263
Percentage of ShareBasedCompensation	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

Net Cash Provided By Used In Investing Activities

us-gaap:NetCashProvidedByUsedInInvestingActivities

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-04-02	2011-01-01	2010-10-02
Value	-17920000.0	-122020000.0	-10045000.0	-11998000.0	-12854000.0	-16536000.0	-23497000.0	-13148000.0	-5568000.0	-14244000.0	-13685000.0	-17829000.0	-26357000.0	-324380000.0	-16936000.0	-43084000.0	-14019000.0	-22098000.0	-12762000.0	-124280000.0	-100980000.0	-273220000.0	-6227000.0	-10548000.0	-12273000.0	-38645000.0	515000.0	-7455000.0	-58408000.0	-6945000.0	-10781000.0	-153940000.0	-13922000.0	-8563000.0	-11087000.0	-24203000.0	-7839000.0	-22759000.0	-15628000.0	-4447000.0	-54736000.0	-8551000.0
Percentage of NetCashProvidedByUsedInInvestingActivities	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	-3.4	-26.3	-2.5	-3.1	-4.2	-4.8	-6.9	-3.6	-1.4	-3.5	-3.4	-4.1	-5.7	-77.6	-5.6	-13.6	-4.5	-7.7	-4.5	-44.3	-37.1	-124.5	-2.9	-4.8	-5.8	-18.7	0.2	-3.4	-28.2	-3.5	-5.4	-82.0	-8.1	-5.4	-6.4	-13.8	-4.9	-15.5	-9.0	-2.7	-38.4	-5.2

Payments To Acquire Property Plant And Equipment

us-gaap:PaymentsToAcquirePropertyPlantAndEquipment

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-04-02	2011-01-01	2010-10-02
Value	17	14	14	12	12	16	23	13	11	14	18	15	22	17	17	20	15	12	11	14	11	9.139	8.628	14	12	12	6.29	6.709	6.423	9.625	10	8.992	5.453	9.732	6.05	3.503	3.244	5.174	1.822	4.614	6.693	8.585
Percentage of PaymentsToAcquirePropertyPlantAndEquipment	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

Net Cash Provided By Used In Financing Activities

us-gaap:NetCashProvidedByUsedInFinancingActivities

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-04-02	2011-01-01	2010-10-02
Value	-14.91	-34.273	-49.432	-68.902	-15.278	65	-10.811	-59.841	-44.291	-31.333	-73.362	-0.948	-44.101	240	-18.19	3.588	-13.017	2.938	21	73	-14.946	203	-7.543	-11.164	-8.445	-84.716	-23.056	-0.912	65	-10.768	-5.222	146	11	-5.702	1.814	-7.666	12	-10.231	-16.858	8.689	17	-15.194
Percentage of NetCashProvidedByUsedInFinancingActivities	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0
Percentage of RevenueFromContractWithCustomerIncludingAssessedTax	-2.8	-7.4	-12.3	-17.6	-5.0	19.0	-3.2	-16.5	-11.1	-7.7	-18.2	-0.2	-9.6	57.5	-6.0	1.1	-4.2	1.0	7.7	26.3	-5.5	92.9	-3.5	-5.0	-4.0	-41.0	-10.6	-0.4	31.6	-5.4	-2.6	78.2	6.6	-3.6	1.1	-4.4	7.7	-7.0	-9.7	5.2	12.3	-9.3

Repayments Of Long Term Debt

us-gaap:RepaymentsOfLongTermDebt us-gaap:CreditFacility, us-gaap:DebtInstrument

us-gaap:RepaymentsOfLongTermDebt

lfus:TermLoanCreditFacility, lfus:CreditAgreement

Period End	2020-09-26	2020-04-03	2020-06-27	2019-06-29
Value	0.0	5.0	2.5	2.5
Percentage of RepaymentsOfLongTermDebt	0.0	100.0	100.0	100.0

Payments Of Dividends

us-gaap:PaymentsOfDividends

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-04-02
Value	11	11	11	11	11	11	11	11	10	10	10	10	9.26	9.198	8.403	8.404	7.491	7.472	7.461	7.41	6.512	6.483	6.568	5.661	5.635	5.632	5.622	4.977	4.944	4.933	4.924	4.455	4.41	4.383	4.375	3.918	3.888	3.875	4.02	3.284
Percentage of PaymentsOfDividends	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

Effective Income Tax Rate Continuing Operations

us-gaap:EffectiveIncomeTaxRateContinuingOperations

Period End	2021-06-26	2021-03-27	2020-09-26	2020-06-27	2020-03-28	2019-09-28	2019-06-29	2019-03-30	2018-09-29	2018-06-30	2018-03-31	2017-09-30	2017-07-01	2017-04-01	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-09-27	2014-06-28	2014-03-29	2013-09-28	2013-06-29	2013-03-30	2012-09-29	2012-06-30	2012-03-31	2011-10-01	2011-07-02
Value	13.8	20.6	17.9	0.151	0.306	0.139	0.182	0.203	0.215	0.191	0.193	0.229	0.152	0.18	-0.012	0.202	0.288	0.104	0.239	0.243	0.273	0.221	0.249	0.261	0.247	0.177	0.226	0.272	0.293	0.197	0.274
Percentage of EffectiveIncomeTaxRateContinuingOperations	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31
Value	148.01	131.32	116.29	110.04	98.65	80.53	67.88	51.93	40.53	34.42
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

Deferred Tax Liabilities

us-gaap:DeferredTaxLiabilities

Period End	2020-12-26	2019-12-28	2018-12-29	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31
Value	38	41	44	25	22	21	21	17	12
Percentage of DeferredTaxLiabilities	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

Deferred Tax Assets Net

us-gaap:DeferredTaxAssetsNet

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31
Value	61	45	42	28	38	23	33	25	37	28
Percentage of DeferredTaxAssetsNet	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

Unrecognized Tax Benefits

us-gaap:UnrecognizedTaxBenefits

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31	2011-01-01	2010-01-02
Value	17	16	18	7.66	8.617	0.102	0.112	0.112	0.112	0.112	0.112	0.496
Percentage of UnrecognizedTaxBenefits	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

Deferred Tax Assets Valuation Allowance

us-gaap:DeferredTaxAssetsValuationAllowance

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31
Value	13	5.957	4.794	6.203	6.738	4.557	4.557	6.25	0.784	0.708
Percentage of DeferredTaxAssetsValuationAllowance	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

lfus:BusinessAcquisitionProFormaIncomeLossFromContinuingOperationsBeforeTax

Period End	2021-06-26	2020-06-27	2018-06-30	2018-03-31	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02
Value	98	-10.392	52	81	40	11	32	32	44
Percentage of BusinessAcquisitionProFormaIncomeLossFromContinuingOperationsBeforeTax	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

lfus:BusinessAcquisitionProFormaIncomeLossfromContinuingOperationsbeforeTax

Period End	2021-03-27	2020-03-28	2018-12-29	2018-09-29	2018-06-30	2017-12-30	2017-09-30
Value	77	31	44	71	74	39	50
Percentage of BusinessAcquisitionProFormaIncomeLossfromContinuingOperationsbeforeTax	100.0	100.0	100.0	100.0	100.0	100.0	100.0

lfus:BusinessCombinationAcquisitionRelatedCostsandIntegrationCostsLegalAccountingandOtherExpenses us-gaap:IncomeStatementLocation, us-gaap:StatementBusinessSegments

lfus:BusinessCombinationAcquisitionRelatedCostsandIntegrationCostsLegalAccountingandOtherExpenses

us-gaap:OperatingIncomeLoss, us-gaap:AllOtherSegments

Period End	2020-09-26	2020-06-27	2019-09-28	2019-06-29	2019-03-30	2018-09-29	2018-06-30	2018-03-31	2017-09-30
Value	0.3	0.1	3.2	1.5	2.4	2.5	2.0	11	4.8
Percentage of BusinessCombinationAcquisitionRelatedCostsandIntegrationCostsLegalAccountingandOtherExpenses	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

lfus:BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentCurrentLiabilities us-gaap:BusinessAcquisition

lfus:BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentCurrentLiabilities

lfus:HartlandControls

Period End	2021-06-26
Value	-300000.0
Percentage of BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentCurrentLiabilities	100.0

lfus:BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentTradeReceivables us-gaap:BusinessAcquisition

lfus:BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentTradeReceivables

lfus:HartlandControls

Period End	2021-06-26
Value	-1300000.0
Percentage of BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentTradeReceivables	100.0

lfus:NonCashInventoryCharges

Period End	2021-06-26	2021-03-27
Value	3.318	3.489
Percentage of NonCashInventoryCharges	100.0	100.0

lfus:NumberofCustomers

Period End	2021-03-27
Value	100000.0
Percentage of NumberofCustomers	100.0

lfus:RepaymentsOfEntrustedLoans

Period End	2020-09-26	2020-06-27	2020-03-28	2019-09-28	2019-06-29	2019-03-30	2018-09-29	2018-06-30	2018-03-31	2017-09-30	2017-07-01	2017-04-01	2015-09-26
Value	0.0	0.0	22	49	31	17	0.0	0.0	0.0	1.183	1.761	0.655	2.411
Percentage of RepaymentsOfEntrustedLoans	0.0	0.0	100.0	100.0	100.0	100.0	0.0	0.0	0.0	100.0	100.0	100.0	100.0

us-gaap:AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation

Period End	2021-06-26	2020-09-26	2020-06-27	2020-03-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	5597000.0	131000.0	2375000.0	443000.0	790000.0	4010000.0	94000.0	0	210000.0	4284000.0	2758000.0
Percentage of AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation	100.0	100.0	100.0	100.0	100.0	100.0	100.0	0.0	100.0	100.0	100.0

us-gaap:AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation us-gaap:StatementEquityComponents

us-gaap:TreasuryStock

Period End	2021-06-26	2020-09-26	2020-06-27	2020-03-28	2019-09-28	2019-06-29	2019-03-30	2018-09-29	2018-06-30	2018-03-31
Value	5597000.0	131000.0	2375000.0	443000.0	790000.0	4010000.0	94000.0	210000.0	4284000.0	2758000.0
Percentage of AdjustmentsRelatedToTaxWithholdingForShareBasedCompensation	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:AssetImpairmentCharges

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2017-12-30	2016-10-01	2014-12-27	2012-12-29	2012-09-29	2011-12-31	2011-10-01	2011-01-01
Value	0.0	0.1	33	2.237	4.2	0.322	0.2	2.8	1.093	0.0	0.0	14	0.3	7.3	0.5	0.0	2.3	0.0
Percentage of AssetImpairmentCharges	0.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	0.0	0.0	100.0	100.0	100.0	100.0	0.0	100.0	0.0

us-gaap:AssetImpairmentCharges us-gaap:IncomeStatementLocation

lfus:OtherExpenseIncome

Period End	2020-09-26	2019-12-28	2019-09-28	2019-06-29	2019-03-30
Value	0.1	4.5	0.0	0.0	2.8
Percentage of AssetImpairmentCharges	100.0	107.1	0.0	0.0	100.0

us-gaap:AssetImpairmentCharges us-gaap:StatementBusinessSegments

lfus:Automotive

Period End	2020-12-26	2020-09-26	2020-06-27	2019-12-28	2019-09-28	2019-06-29
Value	0.0	0.0	33	0.0	0.322	0.0
Percentage of AssetImpairmentCharges	0.0	0.0	100.0	0.0	100.0	0.0

us-gaap:BusinessAcquisitionProFormaEarningsPerShareBasic

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02
Value	3.45	2.5	-0.36	0.88	1.44	2.23	2.37	2.57	-0.79	1.61	1.5	0.7	1.21	1.47	1.61
Percentage of BusinessAcquisitionProFormaEarningsPerShareBasic	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:BusinessAcquisitionProFormaEarningsPerShareDiluted

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02
Value	3.41	2.46	-0.36	0.87	1.37	2.18	2.33	2.53	-0.78	1.59	1.48	0.69	1.2	1.46	1.6
Percentage of BusinessAcquisitionProFormaEarningsPerShareDiluted	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:BusinessAcquisitionsProFormaNetIncomeLoss

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02
Value	84	61	-8.873	21	35	56	59	63	-19.443	40	37	17	27	33	36
Percentage of BusinessAcquisitionsProFormaNetIncomeLoss	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:BusinessAcquisitionsProFormaNetIncomeLoss us-gaap:NonrecurringAdjustment

lfus:AdjustmentToAmortization

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01
Value	-0.001	-0.279	-0.837	-0.834	3.72	3.104	5.185	1.902	-6.298	-6.304	-6.305	-6.276
Percentage of BusinessAcquisitionsProFormaNetIncomeLoss	-0.0	-0.5	9.4	-3.9	10.3	5.5	8.7	3.0	32.4	-15.8	-16.8	-35.9

lfus:AdjustmentToDepreciation

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28	2018-12-29	2018-09-29	2017-12-30	2017-09-30	2017-07-01	2017-04-01
Value	0.0	0.007	0.047	0.048	0.0	0.0	0.139	0.139	0.139	-0.094
Percentage of BusinessAcquisitionsProFormaNetIncomeLoss	0.0	0.0	-0.5	0.2	0.0	0.0	-0.7	0.3	0.4	-0.5

lfus:AdjustmentToIncomeTax

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01
Value	-0.724	-0.831	0.541	1.398	-1.156	-1.011	-13.329	-7.701	3.534	2.906	7.596	15
Percentage of BusinessAcquisitionsProFormaNetIncomeLoss	-0.9	-1.4	-6.1	6.5	-3.2	-1.8	-22.5	-12.0	-18.2	7.3	20.3	88.0

lfus:AmortizationOfInventoryStepUp

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01
Value	3.319	3.49	-1.659	-5.137	0.0	0.0	36	17	0.0	0.0	-14.771	-22.156
Percentage of BusinessAcquisitionsProFormaNetIncomeLoss	3.9	5.7	18.7	-24.0	0.0	0.0	62.3	28.0	-0.0	0.0	-39.5	-126.9

us-gaap:AcquisitionRelatedCosts

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01
Value	0.128	0.707	-0.128	-0.707	0.0	0.0	9.976	9.976	0.0	0.0	0.0	-9.976
Percentage of BusinessAcquisitionsProFormaNetIncomeLoss	0.2	1.2	1.4	-3.3	0.0	0.0	16.8	15.6	-0.0	0.0	0.0	-57.1

us-gaap:BusinessAcquisitionsProFormaRevenue

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02
Value	523	470	323	363	402	439	459	434	393	405	396	368	284	290	286
Percentage of BusinessAcquisitionsProFormaRevenue	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:BusinessCombinationAcquisitionRelatedCosts

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-27	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2012-12-29	2012-09-29	2011-12-31
Value	0.1	0.7	0.7	0.3	0.1	1.2	1.9	3.2	1.5	2.4	3.2	2.9	2.4	11	1.4	4.8	0.3	1.5	3.2	5.9	6.1	6.2	4.0	0.3	0.3	0.2	0.2	0.3	0.4	0.6	0.0
Percentage of BusinessCombinationAcquisitionRelatedCosts	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	0.0

us-gaap:BusinessCombinationAcquisitionRelatedCosts us-gaap:BusinessAcquisition, us-gaap:IncomeStatementLocation, us-gaap:StatementBusinessSegments

lfus:HartlandControls, us-gaap:OperatingIncomeLoss, us-gaap:AllOtherSegments

Period End	2021-06-26	2021-03-27
Value	0.5	0.8
Percentage of BusinessCombinationAcquisitionRelatedCosts	500.0	114.3

us-gaap:BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual us-gaap:BusinessAcquisition

us-gaap:BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual

lfus:HartlandControls

Period End	2021-06-26	2021-03-27
Value	0.3	2.2
Percentage of BusinessCombinationProFormaInformationEarningsOrLossOfAcquireeSinceAcquisitionDateActual	100.0	100.0

us-gaap:BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual us-gaap:BusinessAcquisition

us-gaap:BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual

lfus:HartlandControls

Period End	2021-06-26	2021-03-27
Value	26	16
Percentage of BusinessCombinationProFormaInformationRevenueOfAcquireeSinceAcquisitionDateActual	100.0	100.0

us-gaap:BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentInventory us-gaap:BusinessAcquisition

us-gaap:BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentInventory

lfus:HartlandControls

Period End	2021-06-26	2021-01-28	2021-03-27
Value	-0.5	6.8	3.5
Percentage of BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentInventory	100.0	100.0	100.0

us-gaap:BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentInventory us-gaap:ConsolidationItems, us-gaap:BusinessAcquisition, us-gaap:IncomeStatementLocation

us-gaap:CorporateNonSegment, lfus:HartlandControls, us-gaap:OperatingIncomeLoss

Period End	2021-06-26	2021-03-27
Value	3.3	3.5
Percentage of BusinessCombinationProvisionalInformationInitialAccountingIncompleteAdjustmentInventory	-660.0	100.0

us-gaap:CapitalExpendituresIncurredButNotYetPaid

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29
Value	2.685	4.141	-0.141	1.602	-1.167	5.832	2.132	8.978	0.0	0.0	0.0
Percentage of CapitalExpendituresIncurredButNotYetPaid	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	0.0	0.0	0.0

us-gaap:CashAcquiredFromAcquisition us-gaap:BusinessAcquisition

us-gaap:CashAcquiredFromAcquisition

lfus:HartlandControls

Period End	2021-01-28
Value	112
Percentage of CashAcquiredFromAcquisition	100.0

us-gaap:CashAcquiredFromAcquisition us-gaap:BusinessAcquisition, us-gaap:SubsequentEventType

lfus:HartlandControls, us-gaap:SubsequentEvent

Period End	2021-01-28
Value	113
Percentage of CashAcquiredFromAcquisition	100.6

us-gaap:DefinedBenefitPlanAmortizationOfGainsLosses

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01
Value	-334000.0	-331000.0	-275000.0	-279000.0	-264000.0	-145000.0	-59000.0	-60000.0	-62000.0	-62000.0	-69000.0	-74000.0	-74000.0	-74000.0	-85000.0	-84000.0	-84000.0	-84000.0
Percentage of DefinedBenefitPlanAmortizationOfGainsLosses	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:DefinedBenefitPlanExpectedReturnOnPlanAssets

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-02	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02
Value	371000.0	367000.0	421000.0	422000.0	402000.0	727000.0	803000.0	773000.0	821000.0	790000.0	1602000.0	540000.0	540000.0	540000.0	562000.0	476000.0	476000.0	476000.0	476000.0	375000.0	520000.0	520000.0	520000.0
Percentage of DefinedBenefitPlanExpectedReturnOnPlanAssets	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:DefinedBenefitPlanInterestCost

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-02	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02
Value	443000.0	440000.0	518000.0	511000.0	486000.0	658000.0	795000.0	777000.0	813000.0	784000.0	1601000.0	501000.0	501000.0	501000.0	807000.0	360000.0	360000.0	360000.0	360000.0	173000.0	496000.0	496000.0	497000.0
Percentage of DefinedBenefitPlanInterestCost	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-02	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02
Value	1106000.0	1106000.0	1009000.0	983000.0	940000.0	694000.0	568000.0	573000.0	568000.0	556000.0	735000.0	568000.0	568000.0	568000.0	1143000.0	376000.0	376000.0	376000.0	376000.0	396000.0	382000.0	382000.0	382000.0
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:DefinedBenefitPlanNetPeriodicBenefitCost us-gaap:RetirementPlanSponsorLocation

us-gaap:ForeignPlan

Period End	2021-06-26	2021-03-27	2020-09-26	2020-06-27	2020-03-28	2019-09-28	2019-06-29	2019-03-30
Value	500000.0	500000.0	500000.0	500000.0	500000.0	200000.0	200000.0	200000.0
Percentage of DefinedBenefitPlanNetPeriodicBenefitCost	45.2	45.2	50.9	53.2	72.0	34.9	35.2	36.0

us-gaap:DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1 us-gaap:Range, us-gaap:StatementScenario

us-gaap:DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1

srt:Maximum, srt:ScenarioForecast

Period End	2021-12-31
Value	-22.0
Percentage of DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1	100.0

srt:Minimum, srt:ScenarioForecast

Period End	2021-12-31
Value	-18.0
Percentage of DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1	81.8

us-gaap:DefinedBenefitPlanServiceCost

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-02	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02
Value	700000.0	702000.0	637000.0	615000.0	592000.0	618000.0	517000.0	509000.0	514000.0	500000.0	667000.0	533000.0	533000.0	533000.0	813000.0	408000.0	408000.0	408000.0	408000.0	512000.0	332000.0	333000.0	332000.0
Percentage of DefinedBenefitPlanServiceCost	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:Depreciation

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-04-02	2011-01-01	2010-10-02
Value	13	13	14	14	13	13	13	13	12	13	13	13	12	11	10	9.653	9.447	9.128	8.959	8.685	8.926	7.23	7.393	7.396	7.365	7.638	7.277	7.452	7.007	5.598	6.855	6.516	6.232	6.315	6.37	6.178	6.481	6.611	6.719	5.995	6.274	6.308
Percentage of Depreciation	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:DividendsCommonStockCash

Period End	2021-06-26	2021-03-27	2020-09-26	2020-06-27	2020-03-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	11	11	11	11	11	11	10	10	10	10	9.261	9.198
Percentage of DividendsCommonStockCash	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:DividendsCommonStockCash us-gaap:StatementEquityComponents

us-gaap:RetainedEarnings

Period End	2021-06-26	2021-03-27	2020-09-26	2020-06-27	2020-03-28	2019-09-28	2019-06-29	2019-03-30	2018-09-29	2018-06-30	2018-03-31
Value	11	11	11	11	11	11	10	10	10	9.261	9.198
Percentage of DividendsCommonStockCash	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29
Value	1.207	-4.101	11	7.953	3.417	-5.111	4.925	-6.506	-1.147	1.539	-1.147
Percentage of EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:FinitelivedIntangibleAssetsAcquired1

Period End	2021-03-27	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	39	0.0	0.0	1.12	211
Percentage of FinitelivedIntangibleAssetsAcquired1	100.0	0.0	0.0	100.0	100.0

us-gaap:FinitelivedIntangibleAssetsAcquired1 us-gaap:FiniteLivedIntangibleAssetsByMajorClass

lfus:CustomerListsTrademarksAndTradeNames

Period End	2021-03-27	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	32	0.0	0.0	1.1	147
Percentage of FinitelivedIntangibleAssetsAcquired1	80.9	0.0	0.0	98.2	69.8

lfus:PatentsLicensesAndSoftware

Period End	2021-03-27	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	7.559	0.0	0.0	0.0	51
Percentage of FinitelivedIntangibleAssetsAcquired1	19.1	0.0	0.0	0.0	24.3

us-gaap:ForeignCurrencyTransactionGainLossBeforeTax

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-31	2012-12-29	2012-09-29
Value	1.676	-6.837	5.275	6.174	6.01	-2.584	0.412	-4.968	3.575	-4.243	-5.509	-0.982	-3.2	10	-3.859	-0.632	0.558	1.557	-7.586	4.7	6.237	-3.823	3.549	1.292	-3.117	-1.903	0.101	-2.375	0.252	1.374	-1.476	3.724	-0.319	-1.276	-1.276	-0.834
Percentage of ForeignCurrencyTransactionGainLossBeforeTax	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:GainLossOnSaleOfProperties us-gaap:BusinessAcquisition, us-gaap:StatementBusinessSegments

us-gaap:GainLossOnSaleOfProperties

lfus:HartlandControls, lfus:ElectronicsSegment

Period End	2021-06-26
Value	1000000.0
Percentage of GainLossOnSaleOfProperties	100.0

us-gaap:GainLossOnSaleOfProperties us-gaap:StatementBusinessSegments

lfus:ElectronicsSegment

Period End	2021-03-27
Value	1900000.0
Percentage of GainLossOnSaleOfProperties	0.0

us-gaap:GoodwillAcquiredDuringPeriod

Period End	2021-03-27	2018-03-31
Value	38	381
Percentage of GoodwillAcquiredDuringPeriod	100.0	100.0

us-gaap:GoodwillAcquiredDuringPeriod us-gaap:BusinessAcquisition

lfus:HartlandControls

Period End	2021-03-27
Value	39
Percentage of GoodwillAcquiredDuringPeriod	102.0

us-gaap:GoodwillAcquiredDuringPeriod us-gaap:StatementBusinessSegments

lfus:IndustrialSegment

Period End	2021-03-27
Value	38
Percentage of GoodwillAcquiredDuringPeriod	100.0

us-gaap:GoodwillAndIntangibleAssetImpairment us-gaap:FairValueByMeasurementFrequency

us-gaap:GoodwillAndIntangibleAssetImpairment

us-gaap:FairValueMeasurementsNonrecurring

Period End	2020-12-26
Value	0.0
Percentage of GoodwillAndIntangibleAssetImpairment	0.0

us-gaap:GoodwillForeignCurrencyTranslationGainLoss

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	3.971	-10.155	17	12	8.679	-7.826	6.936	-12.755	0.941	-1.248	-6.343	0.245	-9.065	5.561
Percentage of GoodwillForeignCurrencyTranslationGainLoss	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:GoodwillForeignCurrencyTranslationGainLoss us-gaap:StatementBusinessSegments

lfus:Automotive

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	2.463	1.86	1.821	-1.693	1.519	-2.619	-0.013	0.102	-1.457	-0.292	-4.943	3.195
Percentage of GoodwillForeignCurrencyTranslationGainLoss	14.5	15.3	21.0	21.6	21.9	20.5	-1.4	-8.2	23.0	-119.2	54.5	57.5

lfus:AutomotiveSegment

Period End	2021-06-26	2021-03-27
Value	0.47	-2.012
Percentage of GoodwillForeignCurrencyTranslationGainLoss	11.8	19.8

lfus:Electronics

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	14	10	6.733	-5.873	5.384	-10.098	0.871	-1.4	-4.733	0.468	-4.013	2.455
Percentage of GoodwillForeignCurrencyTranslationGainLoss	84.6	84.2	77.6	75.0	77.6	79.2	92.6	112.2	74.6	191.0	44.3	44.1

lfus:ElectronicsSegment

Period End	2021-06-26	2021-03-27
Value	3.345	-8.124
Percentage of GoodwillForeignCurrencyTranslationGainLoss	84.2	80.0

lfus:Industrial

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	0.151	0.068	0.125	-0.26	0.033	-0.038	0.083	0.05	-0.153	0.069	-0.109	-0.089
Percentage of GoodwillForeignCurrencyTranslationGainLoss	0.9	0.6	1.4	3.3	0.5	0.3	8.8	-4.0	2.4	28.2	1.2	-1.6

lfus:IndustrialSegment

Period End	2021-06-26	2021-03-27
Value	0.156	-0.019
Percentage of GoodwillForeignCurrencyTranslationGainLoss	3.9	0.2

us-gaap:GoodwillImpairmentLoss

Period End	2020-12-26	2020-09-26	2020-06-27	2019-06-29
Value	0.0	0.0	33	0.0
Percentage of GoodwillImpairmentLoss	0.0	0.0	100.0	0.0

us-gaap:GoodwillPurchaseAccountingAdjustments us-gaap:BusinessAcquisition

us-gaap:GoodwillPurchaseAccountingAdjustments

lfus:HartlandControls

Period End	2021-06-26
Value	1500000.0
Percentage of GoodwillPurchaseAccountingAdjustments	100.0

us-gaap:ImpairmentOfInvestments

Period End	2021-06-26
Value	0.5
Percentage of ImpairmentOfInvestments	100.0

us-gaap:IncreaseDecreaseInAccruedLiabilities

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-04-02	2011-01-01	2010-10-02
Value	19	-15.427	8.86	17	-12.132	-7.012	-10.001	-7.528	-9.543	-27.17	17	7.75	-8.8	12	5.884	-2.155	-0.228	4.14	-4.21	0.782	2.215	3.5	-4.552	8.44	2.689	5.503	0.498	-1.123	-6.455	2.837	-0.266	-6.858	-4.619	-4.336	1.696	-1.387	-5.543	-0.393	-0.609	-0.557	-8.779	0.488
Percentage of IncreaseDecreaseInAccruedLiabilities	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:IncreaseDecreaseInContractWithCustomerLiability

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2017-12-30
Value	-159000.0	-157000.0	-155000.0	-149000.0	-144000.0	-145000.0	-90000.0	-228000.0	0	0	0	2044000.0	0
Percentage of IncreaseDecreaseInContractWithCustomerLiability	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	0.0	0.0	0.0	100.0	0.0

us-gaap:IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-04-02	2011-01-01	2010-10-02
Value	10	2.23	-1.001	-3.611	-3.401	1.225	-6.838	-4.825	4.363	-3.273	-2.567	4.52	2.173	3.143	-4.217	-11.22	-6.328	2.011	-17.948	6.379	9.429	2.395	2.145	1.157	-3.579	-5.733	-0.137	-1.458	3.647	-0.846	-0.57	0.302	-1.026	-0.706	1.269	-0.42	-0.101	3.26	-0.765	-2.559	-3.333	6.356
Percentage of IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30
Value	5.125	-5.325	22	16	8.422	-15.54	14	-17.163	-5.892	8.122	-0.522	-7.832	-16.708	-0.276	7.826	1.531	-3.582	4.962	-15.881	-5.771	-14.935	11	-26.377	3.821	-13.974	-15.193	-14.962	6.85	-7.161	1.602	10	-8.021	-5.25
Percentage of OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:OtherComprehensiveIncomeLossBeforeTax

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30
Value	18	16	-4.676	-14.985	4.03	-17.008	-5.691	8.044	-0.228	-7.947	-15.905	-0.344	10	-0.328
Percentage of OtherComprehensiveIncomeLossBeforeTax	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:OtherComprehensiveIncomeLossBeforeTax us-gaap:StatementEquityComponents

us-gaap:AccumulatedDefinedBenefitPlansAdjustment

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29
Value	-7.243	0.273	-13.098	0.555	-9.427	0.155	0.201	-0.078	0.294	-0.115
Percentage of OtherComprehensiveIncomeLossBeforeTax	-39.9	1.6	280.1	-3.7	-233.9	-0.9	-3.5	-1.0	-128.9	1.4

us-gaap:AccumulatedTranslationAdjustment

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29
Value	25	16	8.422	-15.54	13	-17.163	-5.892	8.122	-0.522	-7.832
Percentage of OtherComprehensiveIncomeLossBeforeTax	139.9	98.4	-180.1	103.7	333.9	100.9	103.5	101.0	228.9	98.6

us-gaap:OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	5497000.0	-4819000.0	-4676000.0	-14985000.0
Percentage of OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	100.0	100.0	100.0	100.0

us-gaap:OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent us-gaap:StatementEquityComponents

us-gaap:AccumulatedDefinedBenefitPlansAdjustment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	372000.0	506000.0	-13098000.0	555000.0
Percentage of OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	6.8	-10.5	280.1	-3.7

us-gaap:AccumulatedTranslationAdjustment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	5125000.0	-5325000.0	8422000.0	-15540000.0
Percentage of OtherComprehensiveIncomeLossBeforeTaxPortionAttributableToParent	93.2	110.5	-180.1	103.7

us-gaap:OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	5454000.0	-4871000.0	-2417000.0	-14979000.0
Percentage of OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	100.0	100.0	100.0	100.0

us-gaap:OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent us-gaap:StatementEquityComponents

us-gaap:AccumulatedDefinedBenefitPlansAdjustment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	329000.0	454000.0	-10839000.0	561000.0
Percentage of OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	6.0	-9.3	448.4	-3.7

us-gaap:AccumulatedOtherComprehensiveIncome

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	5454000.0	-4871000.0	-2417000.0	-14979000.0
Percentage of OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	100.0	100.0	100.0	100.0

us-gaap:AccumulatedTranslationAdjustment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	5125000.0	-5325000.0	8422000.0	-15540000.0
Percentage of OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParent	94.0	109.3	-348.4	103.7

us-gaap:OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30
Value	-0.329	-0.454	6.38	-0.563	10	-0.561	8.336	-0.137	-0.161	0.049	-0.229	0.115	-0.766	0.003	-1.588	0.06
Percentage of OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:OtherComprehensiveIncomeLossTax

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30
Value	3027000.0	-290000.0	-2259000.0	-6000.0	-1755000.0	18000.0	40000.0	-29000.0	65000.0	0	37000.0	-65000.0	241000.0	89000.0
Percentage of OtherComprehensiveIncomeLossTax	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	0.0	100.0	100.0	100.0	100.0

us-gaap:OtherComprehensiveIncomeLossTax us-gaap:StatementEquityComponents

us-gaap:AccumulatedDefinedBenefitPlansAdjustment

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29
Value	5973000.0	-290000.0	-2259000.0	-6000.0	1033000.0	18000.0	40000.0	-29000.0	-29000.0	0
Percentage of OtherComprehensiveIncomeLossTax	197.3	100.0	100.0	100.0	-58.9	100.0	100.0	100.0	-44.6	0.0

us-gaap:OtherComprehensiveIncomeLossTaxPortionAttributableToParent1

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	43000.0	52000.0	-2259000.0	-6000.0
Percentage of OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	100.0	100.0	100.0	100.0

us-gaap:OtherComprehensiveIncomeLossTaxPortionAttributableToParent1 us-gaap:StatementEquityComponents

us-gaap:AccumulatedDefinedBenefitPlansAdjustment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	43000.0	52000.0	-2259000.0	-6000.0
Percentage of OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	100.0	100.0	100.0	100.0

us-gaap:OtherNoncashIncomeExpense

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30
Value	0.695	-8.537	9.681	7.327	4.769	-3.547	1.629	-6.258	3.384	-5.393
Percentage of OtherNoncashIncomeExpense	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:PaymentsOfDebtIssuanceCosts

Period End	2020-12-26	2020-09-26	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2014-12-27	2014-09-27	2013-12-28	2013-09-28
Value	0	0	0	0	0	25000.0	0	0	878000.0	1624000.0	1000.0	-70000.0	71000.0	1882000.0	0	1000.0	1700000.0	0	-1000.0	0	0	1000.0
Percentage of PaymentsOfDebtIssuanceCosts	0.0	0.0	0.0	0.0	0.0	100.0	0.0	0.0	100.0	100.0	100.0	100.0	100.0	100.0	0.0	100.0	100.0	0.0	100.0	0.0	0.0	100.0

us-gaap:PaymentsToAcquireBusinessesNetOfCashAcquired

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2012-12-29	2012-09-29	2011-12-31	2011-10-01
Value	0.0	109	0.0	0.0	0.0	0.0	0.0	0.775	4.999	2.988	4.0	306	-0.098	24	0.0	14	472	-1.06	-0.304	-0.027	-0.224	-0.105	3.6	0.0	0.768	52	-0.618	0.0	0.0	10	-0.05	11
Percentage of PaymentsToAcquireBusinessesNetOfCashAcquired	0.0	100.0	0.0	0.0	0.0	0.0	0.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	0.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	0.0	100.0	100.0	100.0	0.0	0.0	100.0	100.0	100.0

us-gaap:PaymentsToAcquireBusinessesNetOfCashAcquired us-gaap:BusinessAcquisition

lfus:HartlandControls

Period End	2021-01-28
Value	109
Percentage of PaymentsToAcquireBusinessesNetOfCashAcquired	0.0

us-gaap:ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28
Value	-3.096	7.509	12	2.795	0.686	2.956	3.388	1.401
Percentage of ProceedsFromIssuanceOfSharesUnderIncentiveAndShareBasedCompensationPlansIncludingStockOptions	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:ProceedsFromLongTermLinesOfCredit

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-25	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30
Value	0.0	0.0	140	100	100	0.0	0.0	0.0	0.0	0.0	0.0	10.0	50	0.0
Percentage of ProceedsFromLongTermLinesOfCredit	0.0	0.0	100.0	100.0	100.0	0.0	0.0	0.0	0.0	0.0	0.0	100.0	100.0	0.0

us-gaap:ProceedsFromSaleOfPropertyPlantAndEquipment

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-04-02	2011-01-01	2010-10-02
Value	0.016	2.553	4.61	0.059	0.039	0.05	0.001	0.0	5.605	0.607	8.714	0.79	0.049	0.019	0.421	0.363	0.121	0.057	-233.752	109	0.0	125	-0.01	0.042	0.006	0.053	0.035	0.022	0.015	0.018	0.102	0.047	0.009	3.169	0.054	0.42	0.021	-0.357	0.321	0.167	0.249	0.034
Percentage of ProceedsFromSaleOfPropertyPlantAndEquipment	100.0	100.0	100.0	100.0	100.0	100.0	100.0	0.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	0.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:PropertyPlantAndEquipmentAdditions

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29
Value	20	12	14	13	11	11	18	17	15	14	18	15	22	17	17	19	16	12	11	9.139	8.738	14	12	12	6.29	6.709	6.423
Percentage of PropertyPlantAndEquipmentAdditions	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:PropertyPlantAndEquipmentAdditions us-gaap:StatementGeographical

country:CN

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29
Value	4.985	2.142	3.66	1.898	2.859	1.657	-2.018	7.46	3.733	1.225	10	4.332	9.567	5.144	10	12	7.808	2.341	2.801	1.046	1.079	3.413	0.667	3.804	0.955	1.821	0.685
Percentage of PropertyPlantAndEquipmentAdditions	24.2	16.8	25.2	13.9	24.4	14.7	-10.6	42.6	23.7	8.7	54.5	27.7	42.7	28.7	60.8	61.3	47.3	18.9	25.3	11.4	12.3	24.2	5.4	29.6	15.2	27.1	10.7

country:DE

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-04-01
Value	1.94	0.593	1.807	1.284	1.756	0.753	-0.318	0.623	3.114	0.598	-0.709	0.735	2.144	3.038	0.026	0.045
Percentage of PropertyPlantAndEquipmentAdditions	9.4	4.7	12.4	9.4	15.0	6.7	-1.7	3.6	19.7	4.2	-3.8	4.7	9.6	17.0	0.1	0.4

country:MX

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-07-02	2016-04-02	2015-09-26	2014-09-27
Value	7.11	6.121	2.686	3.031	1.668	2.592	1.177	3.923	3.243	5.484	4.634	5.215	5.564	3.31	4.354	4.116	3.947	6.978	3.511	4.653	2.328	1.09
Percentage of PropertyPlantAndEquipmentAdditions	34.5	48.1	18.5	22.2	14.2	22.9	6.2	22.4	20.5	39.0	24.6	33.4	24.8	18.5	24.9	21.0	23.9	56.4	31.7	50.9	26.6	17.3

country:PH

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-07-02	2016-04-02
Value	4.498	2.443	4.281	6.292	5.821	3.218	13	2.917	1.4	5.229	1.472	1.892	2.079	2.162	0.961	0.673	0.49	0.855	1.824	1.101
Percentage of PropertyPlantAndEquipmentAdditions	21.8	19.2	29.5	46.1	49.6	28.5	70.5	16.7	8.9	37.1	7.8	12.1	9.3	12.1	5.5	3.4	3.0	6.9	16.5	12.0

country:US

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29
Value	1.049	0.683	1.458	0.686	1.446	0.58	0.892	1.518	2.549	0.905	-0.069	1.402	1.325	2.909	0.766	1.603	0.817	0.332	1.165	1.618	1.752	3.428	3.187	3.919	1.906	1.684	1.625
Percentage of PropertyPlantAndEquipmentAdditions	5.1	5.4	10.0	5.0	12.3	5.1	4.7	8.7	16.2	6.4	-0.4	9.0	5.9	16.2	4.4	8.2	5.0	2.7	10.5	17.7	20.1	24.3	26.0	30.5	30.3	25.1	25.3

lfus:OtherCountries

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29
Value	1.039	0.754	0.623	0.465	-1.821	2.508	5.86	1.076	1.743	0.635	3.236	2.055	1.727	1.346	0.764	1.184	3.439	1.871	7.044	6.406	3.579	3.616	7.887	10	2.339	-1.345	3.968
Percentage of PropertyPlantAndEquipmentAdditions	5.0	5.9	4.3	3.4	-15.5	22.2	30.9	6.1	11.0	4.5	17.2	13.1	7.7	7.5	4.4	6.0	20.8	15.1	63.6	70.1	41.0	25.6	64.2	80.6	37.2	-20.0	61.8

us-gaap:RelatedPartyTransactionPurchasesFromRelatedParty us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:RelatedPartyTransactionPurchasesFromRelatedParty

lfus:ATEC

Period End	2020-09-26	2020-06-27	2020-03-28	2019-09-28	2019-06-29	2019-03-30
Value	2400000.0	1600000.0	1800000.0	1700000.0	2300000.0	1500000.0
Percentage of RelatedPartyTransactionPurchasesFromRelatedParty	100.0	100.0	100.0	100.0	100.0	100.0

lfus:Powersem

Period End	2020-09-26	2020-06-27	2020-03-28	2019-09-28	2019-06-29	2019-03-30
Value	800000.0	800000.0	200000.0	800000.0	900000.0	800000.0
Percentage of RelatedPartyTransactionPurchasesFromRelatedParty	33.3	50.0	11.1	47.1	39.1	53.3

us-gaap:RelatedPartyTransactionPurchasesFromRelatedParty us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

lfus:ATEC, us-gaap:EquityMethodInvestee

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	2800000.0	3000000.0	1600000.0	1800000.0
Percentage of RelatedPartyTransactionPurchasesFromRelatedParty	0.0	0.0	100.0	100.0

lfus:Powersem, us-gaap:EquityMethodInvestee

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	700000.0	1100000.0	800000.0	200000.0
Percentage of RelatedPartyTransactionPurchasesFromRelatedParty	0.0	0.0	50.0	11.1

us-gaap:RepaymentsOfLongTermLinesOfCredit

Period End	2021-06-26	2021-03-27	2020-12-26	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01
Value	0.0	30	50	0.0	0.0	0.0	0.0	0.0	0.0	13	47	15	0.0	0.0	112
Percentage of RepaymentsOfLongTermLinesOfCredit	0.0	100.0	100.0	0.0	0.0	0.0	0.0	0.0	0.0	100.0	100.0	100.0	0.0	0.0	100.0

us-gaap:RepaymentsOfUnsecuredDebt

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01
Value	0.0	0.0	142	2.5	2.5	0.0	2.5	5.0	-0.025	2.5	37	2.5	2.501	1.562	1.562	1.563
Percentage of RepaymentsOfUnsecuredDebt	0.0	0.0	100.0	100.0	100.0	0.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:RestructuringCharges

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2016-07-02	2015-06-27	2014-12-27	2014-09-27	2013-03-30	2012-09-29	2012-06-30	2012-03-31
Value	0.789	0.437	0.812	1.277	1.824	1.725	2.078	2.215	5.683	2.735	1.47	4.982	3.134	0.779	0.1	1.7	2.2	1.1	0.013	0.061	53	0.059
Percentage of RestructuringCharges	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:RestructuringCharges us-gaap:BusinessAcquisition, us-gaap:IncomeStatementLocation, us-gaap:StatementBusinessSegments

lfus:HartlandControls, us-gaap:OperatingIncomeLoss, us-gaap:AllOtherSegments

Period End	2021-06-26
Value	0.8
Percentage of RestructuringCharges	101.4

us-gaap:RestructuringCharges us-gaap:IncomeStatementLocation

us-gaap:OperatingIncomeLoss

Period End	2020-12-26	2020-09-26
Value	0.9	1.2
Percentage of RestructuringCharges	110.8	94.0

us-gaap:RestructuringCharges us-gaap:IncomeStatementLocation, us-gaap:StatementBusinessSegments

us-gaap:OperatingIncomeLoss, us-gaap:AllOtherSegments

Period End	2021-03-27	2020-09-26	2020-06-27	2020-03-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2017-09-30	2016-04-02
Value	0.4	1.3	35	4.0	2.5	5.7	2.7	-1.1	4.6	3.2	1.5	1.4
Percentage of RestructuringCharges	91.5	101.8	1951.8	231.9	112.9	100.3	98.7	-74.8	92.3	102.1	0.0	0.0

us-gaap:RestructuringCharges us-gaap:RestructuringCostAndReserve

us-gaap:EmployeeSeverance

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-04-30	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	0.717	0.42	0.839	1.198	1.815	1.601	1.481	0.813	1.7	5.613	2.452	1.444	4.816	2.464	0.779
Percentage of RestructuringCharges	90.9	96.1	103.3	93.8	99.5	92.8	71.3	36.7	98.8	0.0	89.7	98.2	96.7	78.6	100.0

us-gaap:OtherRestructuring

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-04-30	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30
Value	0.072	0.017	-0.027	0.079	0.009	0.124	0.597	1.402	1.1	0.07	0.283	0.026	0.166	0.67
Percentage of RestructuringCharges	9.1	3.9	-3.3	6.2	0.5	7.2	28.7	63.3	1.2	0.0	10.3	1.8	3.3	21.4

us-gaap:RestructuringCharges us-gaap:RestructuringCostAndReserve, us-gaap:StatementBusinessSegments

us-gaap:EmployeeSeverance, lfus:Automotive

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	-0.088	0.162	0.209	0.399	0.296	0.109	3.241	0.605	0.333	0.202	0.0	0.099
Percentage of RestructuringCharges	-10.8	12.7	11.5	23.1	14.2	4.9	57.0	22.1	22.7	4.1	0.0	12.7

us-gaap:EmployeeSeverance, lfus:AutomotiveSegment

Period End	2021-06-26	2020-06-27	2020-03-28
Value	0.416	0.209	0.399
Percentage of RestructuringCharges	52.7	11.5	23.1

us-gaap:EmployeeSeverance, lfus:Electronics

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	0.415	0.388	0.856	0.881	1.16	0.655	1.698	1.8	1.049	4.614	2.402	0.677
Percentage of RestructuringCharges	51.1	30.4	46.9	51.1	55.8	29.6	29.9	65.8	71.4	92.6	76.6	86.9

us-gaap:EmployeeSeverance, lfus:ElectronicsSegment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	0.295	0.257	0.856	0.881
Percentage of RestructuringCharges	37.4	58.8	46.9	51.1

us-gaap:EmployeeSeverance, lfus:Industrial

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	0.512	0.648	0.75	0.321	0.025	0.049	0.674	0.047	0.062	0.0	0.062	0.003
Percentage of RestructuringCharges	63.1	50.7	41.1	18.6	1.2	2.2	11.9	1.7	4.2	0.0	2.0	0.4

us-gaap:EmployeeSeverance, lfus:IndustrialSegment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	0.006	0.163	0.75	0.321
Percentage of RestructuringCharges	0.8	37.3	41.1	18.6

us-gaap:OtherRestructuring, lfus:Automotive

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30
Value	0.067	0.0	-0.012	0.12	0.474	1.15	0.07	0.02	0.026	0.166	0.0
Percentage of RestructuringCharges	8.3	0.0	-0.7	7.0	22.8	51.9	1.2	0.7	1.8	3.3	0.0

us-gaap:OtherRestructuring, lfus:AutomotiveSegment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	0.072	0.017	-0.012	0.12
Percentage of RestructuringCharges	9.1	3.9	-0.7	7.0

us-gaap:OtherRestructuring, lfus:Industrial

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30
Value	-0.094	0.079	0.022	0.003	0.076	0.124	0.0	0.25	0.0	0.0	0.0
Percentage of RestructuringCharges	-11.6	6.2	1.2	0.2	3.7	5.6	0.0	9.1	0.0	0.0	0.0

us-gaap:RestructuringCharges us-gaap:StatementBusinessSegments

lfus:Automotive

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	-0.021	0.162	0.197	0.519	0.77	1.259	3.311	0.625	0.359	0.368	0.0	0.099
Percentage of RestructuringCharges	-2.6	12.7	10.8	30.1	37.1	56.8	58.3	22.9	24.4	7.4	0.0	12.7

lfus:AutomotiveSegment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	0.488	0.017	0.197	0.519
Percentage of RestructuringCharges	61.9	3.9	10.8	30.1

lfus:Electronics

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	0.415	0.388	0.855	0.882	1.207	0.783	1.698	1.813	1.049	4.614	3.072	0.677
Percentage of RestructuringCharges	51.1	30.4	46.9	51.1	58.1	35.3	29.9	66.3	71.4	92.6	98.0	86.9

lfus:ElectronicsSegment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	0.295	0.257	0.855	0.882
Percentage of RestructuringCharges	37.4	58.8	46.9	51.1

lfus:Industrial

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	0.418	0.727	0.772	0.324	0.101	0.173	0.674	0.297	0.062	0.0	0.062	0.003
Percentage of RestructuringCharges	51.5	56.9	42.3	18.8	4.9	7.8	11.9	10.9	4.2	0.0	2.0	0.4

lfus:IndustrialSegment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	0.006	0.163	0.772	0.324
Percentage of RestructuringCharges	0.8	37.3	42.3	18.8

us-gaap:RestructuringCostsAndAssetImpairmentCharges

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30
Value	0.789	0.437	0.8	1.277	35	3.962	2.1	2.537	5.683	2.735	2.4	5.2	4.2
Percentage of RestructuringCostsAndAssetImpairmentCharges	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:RestructuringCostsAndAssetImpairmentCharges us-gaap:StatementBusinessSegments

lfus:Automotive

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30
Value	-0.021	0.162	34	0.519	0.77	1.581	3.311	0.625	0.359	0.368	0.088
Percentage of RestructuringCostsAndAssetImpairmentCharges	-2.6	12.7	95.4	13.1	36.7	62.3	58.3	22.9	15.0	7.1	2.1

lfus:AutomotiveSegment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	0.488	0.017	34	0.519
Percentage of RestructuringCostsAndAssetImpairmentCharges	61.9	3.9	95.4	13.1

lfus:Electronics

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30
Value	0.415	0.388	0.855	0.882	1.207	0.783	1.698	1.813	1.049	4.614	3.072
Percentage of RestructuringCostsAndAssetImpairmentCharges	51.9	30.4	2.4	22.3	57.5	30.9	29.9	66.3	43.7	88.7	73.1

lfus:ElectronicsSegment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	0.295	0.257	0.855	0.882
Percentage of RestructuringCostsAndAssetImpairmentCharges	37.4	58.8	2.4	22.3

lfus:Industrial

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30
Value	0.418	0.727	0.772	2.561	0.101	0.173	0.674	0.297	1.155	0.0	1.099
Percentage of RestructuringCostsAndAssetImpairmentCharges	52.2	56.9	2.2	64.6	4.8	6.8	11.9	10.9	48.1	0.0	26.2

lfus:IndustrialSegment

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	0.006	0.163	0.772	2.561
Percentage of RestructuringCostsAndAssetImpairmentCharges	0.8	37.3	2.2	64.6

us-gaap:RestructuringSettlementAndImpairmentProvisions

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	0.789	0.437	35	3.962
Percentage of RestructuringSettlementAndImpairmentProvisions	100.0	100.0	100.0	100.0

us-gaap:RevenueFromRelatedParties us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:RevenueFromRelatedParties

lfus:Powersem

Period End	2020-09-26	2020-06-27	2020-03-28	2019-09-28	2019-06-29	2019-03-30
Value	400000.0	300000.0	400000.0	200000.0	100000.0	100000.0
Percentage of RevenueFromRelatedParties	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:RevenueFromRelatedParties us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

lfus:Powersem, us-gaap:EquityMethodInvestee

Period End	2021-06-26	2021-03-27	2020-06-27	2020-03-28
Value	0	200000.0	300000.0	400000.0
Percentage of RevenueFromRelatedParties	0.0	0.0	100.0	100.0

us-gaap:StockIssuedDuringPeriodValueStockOptionsExercised

Period End	2021-06-26	2021-03-27	2020-09-26	2020-06-27	2020-03-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	2.502	7.509	2.927	3.06	3.399	2.192	4.823	2.292	0.938	7.517	8.045	9.609
Percentage of StockIssuedDuringPeriodValueStockOptionsExercised	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:StockIssuedDuringPeriodValueStockOptionsExercised us-gaap:StatementEquityComponents

us-gaap:AdditionalPaidInCapital

Period End	2021-06-26	2021-03-27	2020-09-26	2020-06-27	2020-03-28	2019-09-28	2019-06-29	2019-03-30	2018-09-29	2018-06-30	2018-03-31
Value	2.501	7.509	2.926	3.059	3.399	2.191	4.822	2.292	7.516	8.043	9.609
Percentage of StockIssuedDuringPeriodValueStockOptionsExercised	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:CommonStock

Period End	2021-06-26	2020-09-26	2020-06-27	2019-09-28	2019-06-29	2018-09-29	2018-06-30
Value	0.001	0.001	0.001	0.001	0.001	0.001	0.002
Percentage of StockIssuedDuringPeriodValueStockOptionsExercised	0.0	0.0	0.0	0.0	0.0	0.0	0.0

us-gaap:TreasuryStockValueAcquiredCostMethod

Period End	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30
Value	0.027	0.0	-0.027	22	0.036	49	31	13
Percentage of TreasuryStockValueAcquiredCostMethod	100.0	0.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:UnrealizedGainLossOnInvestments

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	1190000.0	7675000.0	3463000.0	1742000.0	2062000.0	-2604000.0	-4295000.0	1899000.0	352000.0	-2810000.0	320000.0	-2961000.0	1447000.0	1864000.0
Percentage of UnrealizedGainLossOnInvestments	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:WeightedAverageNumberDilutedSharesOutstandingAdjustment

Period End	2021-06-26	2021-03-27	2020-09-26	2020-06-27	2020-03-28	2019-09-28	2019-06-29	2019-03-30	2018-09-29	2018-06-30	2018-03-31	2017-09-30	2017-07-01	2017-04-01	2016-10-01	2016-07-02	2016-04-02	2015-09-26	2015-06-27	2015-03-28	2014-09-27	2014-06-28	2014-03-29	2013-09-28	2013-06-29	2013-03-30	2012-09-29	2012-06-30	2012-03-31	2011-10-01	2011-07-02
Value	308000.0	360000.0	216000.0	0	185000.0	202000.0	243000.0	292000.0	362000.0	397000.0	436000.0	240000.0	201000.0	241000.0	156000.0	146000.0	183000.0	112000.0	144000.0	181000.0	153000.0	171000.0	225000.0	197000.0	203000.0	271000.0	239000.0	296000.0	321000.0	287000.0	399000.0
Percentage of WeightedAverageNumberDilutedSharesOutstandingAdjustment	100.0	100.0	100.0	0.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

lfus:AnnualizedSales dei:LegalEntity

lfus:AnnualizedSales

lfus:HartlandControls

Period End	2021-01-28
Value	70
Percentage of AnnualizedSales	100.0

lfus:AnnualizedSales dei:LegalEntity, us-gaap:SubsequentEventType

lfus:HartlandControls, us-gaap:SubsequentEvent

Period End	2021-01-28
Value	70
Percentage of AnnualizedSales	100.0

lfus:DeferredTaxAssetsCapitalizedExpense

Period End	2020-12-26	2019-12-28	2018-12-29
Value	4178000.0	2400000.0	0
Percentage of DeferredTaxAssetsCapitalizedExpense	100.0	100.0	0.0

lfus:DeferredTaxLiabilitiesRecognizedonUndistributedForeignEarnings

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	14	13	12	12
Percentage of DeferredTaxLiabilitiesRecognizedonUndistributedForeignEarnings	100.0	100.0	100.0	100.0

lfus:DeferredTaxLiabilitiesRecognizedonUndistributedForeignEarnings us-gaap:IncomeTaxAuthority

us-gaap:DomesticCountry

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	0.3	0.4	0.2	0.2
Percentage of DeferredTaxLiabilitiesRecognizedonUndistributedForeignEarnings	2.1	3.1	1.6	1.7

us-gaap:ForeignCountry

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	13	12	12	11
Percentage of DeferredTaxLiabilitiesRecognizedonUndistributedForeignEarnings	97.9	96.9	98.4	98.3

lfus:DefinedContributionPlanPlanAssets us-gaap:BalanceSheetLocation

lfus:DefinedContributionPlanPlanAssets

lfus:OtherLongtermLiabilities

Period End	2020-12-26
Value	13
Percentage of DefinedContributionPlanPlanAssets	100.0

lfus:FiniteLivedIntangibleAssetExpectedAmortizationAfterYearFour

Period End	2021-06-26	2021-03-27	2020-09-26
Value	143	143	146
Percentage of FiniteLivedIntangibleAssetExpectedAmortizationAfterYearFour	100.0	100.0	100.0

lfus:FinitelivedIntangibleAssetsTotalEstimatedAmortizationExpense

Period End	2021-06-26	2021-03-27	2020-09-26
Value	328	327	326
Percentage of FinitelivedIntangibleAssetsTotalEstimatedAmortizationExpense	100.0	100.0	100.0

lfus:OtherCustomerReserves

Period End	2020-12-26	2019-12-28
Value	3858000.0	1143000.0
Percentage of OtherCustomerReserves	100.0	100.0

lfus:PotentialTaxCharges us-gaap:IncomeTaxAuthorityName

lfus:PotentialTaxCharges

us-gaap:CanadaRevenueAgency

Period End	2020-12-26
Value	3000000.0
Percentage of PotentialTaxCharges	100.0

us-gaap:AccountsPayableRelatedPartiesCurrentAndNoncurrent us-gaap:CounterpartyName, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:AccountsPayableRelatedPartiesCurrentAndNoncurrent

lfus:ATEC, us-gaap:EquityMethodInvestee

Period End	2020-12-26	2019-12-28
Value	200000.0	100000.0
Percentage of AccountsPayableRelatedPartiesCurrentAndNoncurrent	100.0	100.0

lfus:Powersem, us-gaap:EquityMethodInvestee

Period End	2020-12-26	2019-12-28
Value	100000.0	200000.0
Percentage of AccountsPayableRelatedPartiesCurrentAndNoncurrent	50.0	200.0

us-gaap:AccountsPayableRelatedPartiesCurrentAndNoncurrent us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

lfus:ATEC

Period End	2020-09-26	2020-06-27	2020-03-28	2019-12-28
Value	100000.0	100000.0	0	100000.0
Percentage of AccountsPayableRelatedPartiesCurrentAndNoncurrent	0.0	0.0	0.0	100.0

lfus:Powersem

Period End	2020-09-26	2020-06-27	2020-03-28	2019-12-28
Value	100000.0	200000.0	100000.0	200000.0
Percentage of AccountsPayableRelatedPartiesCurrentAndNoncurrent	0.0	0.0	0.0	200.0

us-gaap:AccountsPayableRelatedPartiesCurrentAndNoncurrent us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

lfus:ATEC, us-gaap:EquityMethodInvestee

Period End	2021-06-26	2021-03-27	2020-12-26
Value	1800000.0	300000.0	200000.0
Percentage of AccountsPayableRelatedPartiesCurrentAndNoncurrent	0.0	0.0	100.0

lfus:Powersem, us-gaap:EquityMethodInvestee

Period End	2021-06-26	2021-03-27	2020-12-26
Value	100000.0	200000.0	100000.0
Percentage of AccountsPayableRelatedPartiesCurrentAndNoncurrent	0.0	0.0	50.0

us-gaap:AccountsReceivableRelatedParties us-gaap:CounterpartyName, us-gaap:RelatedPartyTransactionsByRelatedParty

us-gaap:AccountsReceivableRelatedParties

lfus:Powersem, us-gaap:EquityMethodInvestee

Period End	2020-12-26
Value	100000.0
Percentage of AccountsReceivableRelatedParties	100.0

us-gaap:AccountsReceivableRelatedParties us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

lfus:Powersem

Period End	2020-09-26	2020-06-27	2020-03-28	2019-12-28
Value	100000.0	100000.0	100000.0	0
Percentage of AccountsReceivableRelatedParties	0.0	0.0	0.0	0.0

us-gaap:AccountsReceivableRelatedParties us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName, us-gaap:RelatedPartyTransactionsByRelatedParty

lfus:Powersem, us-gaap:EquityMethodInvestee

Period End	2020-12-26
Value	100000.0
Percentage of AccountsReceivableRelatedParties	100.0

us-gaap:AccrualForTaxesOtherThanIncomeTaxesCurrent

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2017-12-30
Value	8.815	1.903	2.126	3.509	2.075	2.058	1.94	32	30	25	21	15
Percentage of AccrualForTaxesOtherThanIncomeTaxesCurrent	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:AccruedProfessionalFeesCurrent

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2017-12-30
Value	2962000.0	3010000.0	3321000.0	2869000.0	3130000.0	3359000.0	3986000.0	4117000.0	4595000.0	5395000.0	6169000.0	2214000.0
Percentage of AccruedProfessionalFeesCurrent	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:AllowanceForDoubtfulAccountsReceivableCurrent

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31	2011-01-01
Value	46	42	45	42	39	37	42	39	34	33	36	36	34	33	27	0.030658	25	17	19	16	13	12	13
Percentage of AllowanceForDoubtfulAccountsReceivableCurrent	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:AllowanceForDoubtfulAccountsReceivableNoncurrent

Period End	2020-12-26	2019-12-28
Value	1400000.0	1300000.0
Percentage of AllowanceForDoubtfulAccountsReceivableNoncurrent	100.0	100.0

us-gaap:AssetsFairValueDisclosure

Period End	2021-06-26	2021-03-27	2020-12-26	2019-12-28	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2011-12-31
Value	67	105	105	142	11	14	12	12	13	15	13	12	11	11	11	18	10	16	22
Percentage of AssetsFairValueDisclosure	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:AssetsFairValueDisclosure us-gaap:FairValueByFairValueHierarchyLevel

us-gaap:FairValueInputsLevel1

Period End	2021-06-26	2021-03-27	2020-12-26	2019-12-28	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2011-12-31
Value	67	105	105	142	11	14	12	12	13	15	13	12	11	11	11	10	10	16	22
Percentage of AssetsFairValueDisclosure	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	54.4	100.0	100.0	100.0

us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets us-gaap:BusinessAcquisition

us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets

lfus:HartlandControls

Period End	2021-01-28
Value	2.384
Percentage of BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets	100.0

us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables us-gaap:BusinessAcquisition

us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables

lfus:HartlandControls

Period End	2021-01-28
Value	14
Percentage of BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables	100.0

us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities us-gaap:BusinessAcquisition

us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities

lfus:HartlandControls

Period End	2021-01-28
Value	25
Percentage of BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities	100.0

us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill us-gaap:BusinessAcquisition

us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill

lfus:HartlandControls

Period End	2021-01-28
Value	39
Percentage of BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill	100.0

us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory us-gaap:BusinessAcquisition

us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory

lfus:HartlandControls

Period End	2021-01-28
Value	36
Percentage of BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory	100.0

us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities us-gaap:BusinessAcquisition

us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities

lfus:HartlandControls

Period End	2021-01-28
Value	6.546
Percentage of BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities	100.0

us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentAssets us-gaap:BusinessAcquisition

us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentAssets

lfus:HartlandControls

Period End	2021-01-28
Value	3.542
Percentage of BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentAssets	100.0

us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment us-gaap:BusinessAcquisition

us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment

lfus:HartlandControls

Period End	2021-01-28
Value	6.296
Percentage of BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment	100.0

us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet us-gaap:BusinessAcquisition

us-gaap:BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet

lfus:HartlandControls

Period End	2021-01-28
Value	109
Percentage of BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet	100.0

us-gaap:CashAndCashEquivalentsFairValueDisclosure

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2016-12-31	2016-01-02	2014-12-27
Value	25	66	73	92	148	198	118	1.428	2.061	9.247
Percentage of CashAndCashEquivalentsFairValueDisclosure	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:CashAndCashEquivalentsFairValueDisclosure us-gaap:FairValueByFairValueHierarchyLevel

us-gaap:FairValueInputsLevel1

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2016-12-31	2016-01-02	2014-12-27
Value	25	66	73	92	148	198	118	0.476	2.061	9.247
Percentage of CashAndCashEquivalentsFairValueDisclosure	100.0	100.0	100.0	100.0	100.0	100.0	100.0	33.3	100.0	100.0

us-gaap:DebtInstrumentCarryingAmount

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	691	682	699	500
Percentage of DebtInstrumentCarryingAmount	100.0	100.0	100.0	100.0

us-gaap:DebtInstrumentCarryingAmount us-gaap:DebtInstrument, us-gaap:LongtermDebtType

lfus:EuroSeniorNotesSeriesA, us-gaap:SeniorNotes

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2019-12-28
Value	139	138	142	136	129
Percentage of DebtInstrumentCarryingAmount	0.0	0.0	20.6	0.0	19.0

lfus:EuroSeniorNotesSeriesB, us-gaap:SeniorNotes

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2019-12-28
Value	113	112	115	110	105
Percentage of DebtInstrumentCarryingAmount	0.0	0.0	16.8	0.0	15.4

us-gaap:DebtInstrumentCarryingAmount us-gaap:LongtermDebtType

us-gaap:LineOfCredit

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2018-03-31	2016-12-31
Value	100	100	130	180	240	100	0.0	3.0	112
Percentage of DebtInstrumentCarryingAmount	0.0	0.0	18.8	0.0	0.0	0.0	0.0	0.0	0.0

us-gaap:NotesPayableOtherPayables

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30
Value	2.619	2.619	2.619	2.619	2.619	2.619	2.619	2.619	2.619	2.619	2.619	2.694	0.06	0.111	0.0
Percentage of DebtInstrumentCarryingAmount	0.0	0.0	0.4	0.0	0.0	0.0	0.4	0.0	0.0	0.0	0.4	0.0	0.0	0.0	0.0

us-gaap:DeferredCompensationArrangementWithIndividualRecordedLiability us-gaap:BalanceSheetLocation

us-gaap:DeferredCompensationArrangementWithIndividualRecordedLiability

us-gaap:OtherAssets

Period End	2020-12-26
Value	13
Percentage of DeferredCompensationArrangementWithIndividualRecordedLiability	100.0

us-gaap:DeferredFinanceCostsNet

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02
Value	3671000.0	3876000.0	4114000.0	4295000.0	4467000.0	3429000.0	3669000.0	3893000.0	4155000.0	4380000.0	4636000.0	4892000.0	5184000.0	5560000.0	4881000.0	3432000.0	3567000.0	3742000.0	3820000.0	2092000.0	2212000.0	1673000.0	721000.0
Percentage of DeferredFinanceCostsNet	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:DeferredIncomeTaxAssetsNet

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2018-12-29	2017-12-30
Value	9.837	9.854	11	7.173	7.555	7.608	8.069	7.485	9.2	7.33	11
Percentage of DeferredIncomeTaxAssetsNet	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:DeferredIncomeTaxLiabilities

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31
Value	100	87	87	33	25
Percentage of DeferredIncomeTaxLiabilities	100.0	100.0	100.0	100.0	100.0

us-gaap:DeferredRevenue

Period End	2021-06-26	2021-03-27	2020-12-26	2019-12-28
Value	2444000.0	2713000.0	2959000.0	828000.0
Percentage of DeferredRevenue	100.0	100.0	100.0	100.0

us-gaap:DeferredTaxAssetInterestCarryforward

Period End	2020-12-26	2019-12-28	2018-12-29
Value	10	5.324	0.885
Percentage of DeferredTaxAssetInterestCarryforward	100.0	100.0	100.0

us-gaap:DeferredTaxAssetsGross

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31
Value	75	51	47	34	45	27	37	31	37	29
Percentage of DeferredTaxAssetsGross	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:DeferredTaxAssetsOperatingLossCarryforwards

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31
Value	24	10	8.613	5.778	2.223	0.684	0.525	0.89	2.33	1.608
Percentage of DeferredTaxAssetsOperatingLossCarryforwards	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:DeferredTaxAssetsTaxCreditCarryforwardsForeign

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31
Value	772000.0	1320000.0	1506000.0	1053000.0	6472000.0	1529000.0	5299000.0	6263000.0	9638000.0	9627000.0
Percentage of DeferredTaxAssetsTaxCreditCarryforwardsForeign	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:DeferredTaxAssetsTaxCreditCarryforwardsOther

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	117000.0	1261000.0	1539000.0	0
Percentage of DeferredTaxAssetsTaxCreditCarryforwardsOther	100.0	100.0	100.0	0.0

us-gaap:DeferredTaxAssetsTaxCreditCarryforwardsResearch

Period End	2020-12-26	2019-12-28	2018-12-29	2013-12-28	2012-12-29	2011-12-31
Value	3724000.0	2581000.0	1245000.0	147000.0	147000.0	1013000.0
Percentage of DeferredTaxAssetsTaxCreditCarryforwardsResearch	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31
Value	31	28	35	24	31	19	27	16	21	15
Percentage of DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAccruedLiabilities	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:DeferredTaxLiabilitiesGoodwillAndIntangibleAssets

Period End	2020-12-26	2019-12-28
Value	76	71
Percentage of DeferredTaxLiabilitiesGoodwillAndIntangibleAssets	100.0	100.0

us-gaap:DeferredTaxLiabilitiesPropertyPlantAndEquipment

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31
Value	4.394	74	74	21	23	22	21	21	16	10
Percentage of DeferredTaxLiabilitiesPropertyPlantAndEquipment	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:DeferredTaxLiabilitiesUndistributedForeignEarnings

Period End	2020-12-26	2019-12-28	2018-12-29	2018-03-31	2017-12-30	2016-12-31	2016-12-30
Value	14	12	12	12	12	1.75	1.8
Percentage of DeferredTaxLiabilitiesUndistributedForeignEarnings	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:DeferredTaxLiabilitiesUnrealizedCurrencyTransactionGains

Period End	2020-12-26
Value	5719000.0
Percentage of DeferredTaxLiabilitiesUnrealizedCurrencyTransactionGains	100.0

us-gaap:DefinedBenefitPlanAccumulatedBenefitObligation us-gaap:RetirementPlanSponsorLocation

us-gaap:DefinedBenefitPlanAccumulatedBenefitObligation

us-gaap:ForeignPlan

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	137	111	99	60
Percentage of DefinedBenefitPlanAccumulatedBenefitObligation	100.0	100.0	100.0	100.0

us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31
Value	41	19	11	12	13	9.383	42	23	32	20
Percentage of DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31
Value	-37285000.0	-15635000.0	-9777000.0	-12261000.0	-13107000.0	-9383000.0	-42472000.0	-23689000.0	-32698000.0	-20779000.0
Percentage of DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2011-12-31
Value	3937000.0	4273000.0	1607000.0	0	-15000.0
Percentage of DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax	100.0	100.0	100.0	0.0	100.0

us-gaap:DefinedBenefitPlanAmountsRecognizedInBalanceSheet

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31
Value	-48514000.0	-38419000.0	-32157000.0	-19145000.0	-13398000.0	-5653000.0	-16915000.0	-8528000.0	-21692000.0	-15097000.0
Percentage of DefinedBenefitPlanAmountsRecognizedInBalanceSheet	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	39000.0	885000.0	811000.0	78000.0
Percentage of DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent	100.0	100.0	100.0	100.0

us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31
Value	1.2	0.023	0.031	0.031	0.026
Percentage of DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate	100.0	100.0	100.0	100.0	100.0

us-gaap:DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31
Value	4.9	0.047	0.046	0.05	0.045
Percentage of DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationRateOfCompensationIncrease	100.0	100.0	100.0	100.0	100.0

us-gaap:DefinedBenefitPlanBenefitObligation

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31	2011-01-01
Value	3.5	2.8	102	67	55	50	158	134	110	107	103
Percentage of DefinedBenefitPlanBenefitObligation	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:DefinedBenefitPlanBenefitObligation us-gaap:BalanceSheetLocation

us-gaap:AccountsPayableAndAccruedLiabilities

Period End	2020-12-26	2019-12-28	2018-12-29
Value	1.2	0.9	1.1
Percentage of DefinedBenefitPlanBenefitObligation	34.3	32.1	1.1

us-gaap:OtherNoncurrentLiabilities

Period End	2020-12-26	2019-12-28	2018-12-29
Value	2.3	1.9	1.6
Percentage of DefinedBenefitPlanBenefitObligation	65.7	67.9	1.6

us-gaap:DefinedBenefitPlanBenefitObligation us-gaap:RetirementPlanType

us-gaap:PensionPlansDefinedBenefit

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31	2016-01-02
Value	148	116	102	67	55	50
Percentage of DefinedBenefitPlanBenefitObligation	4256.9	4175.8	100.0	100.0	100.0	100.0

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter

Period End	2020-12-26
Value	31
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter	100.0

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths

Period End	2020-12-26
Value	6.562
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths	100.0

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive

Period End	2020-12-26
Value	5357000.0
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive	100.0

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour

Period End	2020-12-26
Value	4742000.0
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour	100.0

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree

Period End	2020-12-26
Value	4902000.0
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree	100.0

us-gaap:DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo

Period End	2020-12-26
Value	4718000.0
Percentage of DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo	100.0

us-gaap:DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26
Value	2200000.0	2200000.0	2200000.0	2300000.0
Percentage of DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear	100.0	100.0	100.0	100.0

us-gaap:DefinedBenefitPlanFairValueOfPlanAssets

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31	2011-01-01
Value	100	78	70	48	42	44	141	126	88	92	98
Percentage of DefinedBenefitPlanFairValueOfPlanAssets	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:DefinedBenefitPlanFairValueOfPlanAssets us-gaap:DefinedBenefitPlanByPlanAssetCategories

lfus:BulkAnnuityContract

Period End	2020-12-26
Value	53
Percentage of DefinedBenefitPlanFairValueOfPlanAssets	52.8

lfus:DefinedBenefitPlanInsuranceContractsandOther

Period End	2020-12-26	2019-12-28	2018-12-29
Value	2.565	0.756	1.793
Percentage of DefinedBenefitPlanFairValueOfPlanAssets	2.6	1.0	2.5

us-gaap:DefinedBenefitPlanCashAndCashEquivalents

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	4.522	0.565	1.525	0.404
Percentage of DefinedBenefitPlanFairValueOfPlanAssets	4.5	0.7	2.2	0.8

us-gaap:DefinedBenefitPlanDebtSecurity

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	31	56	46	30
Percentage of DefinedBenefitPlanFairValueOfPlanAssets	31.5	71.6	65.8	63.7

us-gaap:DefinedBenefitPlanEquitySecurities

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	8.623	20	20	17
Percentage of DefinedBenefitPlanFairValueOfPlanAssets	8.6	26.7	29.6	35.5

us-gaap:DefinedBenefitPlanFairValueOfPlanAssets us-gaap:DefinedBenefitPlanByPlanAssetCategories, us-gaap:FairValueByFairValueHierarchyLevel

lfus:BulkAnnuityContract, us-gaap:FairValueInputsLevel3

Period End	2020-12-26
Value	53
Percentage of DefinedBenefitPlanFairValueOfPlanAssets	52.8

lfus:DefinedBenefitPlanInsuranceContractsandOther, us-gaap:FairValueInputsLevel2

Period End	2020-12-26	2019-12-28	2018-12-29
Value	1.88	0.0	0.0
Percentage of DefinedBenefitPlanFairValueOfPlanAssets	1.9	0.0	0.0

lfus:DefinedBenefitPlanInsuranceContractsandOther, us-gaap:FairValueInputsLevel3

Period End	2020-12-26	2019-12-28	2018-12-29
Value	0.685	0.609	0.632
Percentage of DefinedBenefitPlanFairValueOfPlanAssets	0.7	0.8	0.9

us-gaap:DefinedBenefitPlanCashAndCashEquivalents, us-gaap:FairValueInputsLevel1

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	0.654	0.387	0.702	0.173
Percentage of DefinedBenefitPlanFairValueOfPlanAssets	0.7	0.5	1.0	0.4

us-gaap:DefinedBenefitPlanCashAndCashEquivalents, us-gaap:FairValueInputsLevel2

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	3.868	0.0	0.0	0.0
Percentage of DefinedBenefitPlanFairValueOfPlanAssets	3.8	0.0	0.0	0.0

us-gaap:DefinedBenefitPlanDebtSecurity, us-gaap:FairValueInputsLevel1

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	6.164	4.535	3.336	8.088
Percentage of DefinedBenefitPlanFairValueOfPlanAssets	6.1	5.8	4.7	16.8

us-gaap:DefinedBenefitPlanDebtSecurity, us-gaap:FairValueInputsLevel2

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	19	0.0	0.0	0.0
Percentage of DefinedBenefitPlanFairValueOfPlanAssets	19.3	0.0	0.0	0.0

us-gaap:DefinedBenefitPlanDebtSecurity, us-gaap:FairValueMeasuredAtNetAssetValuePerShare

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	6.078	51	43	22
Percentage of DefinedBenefitPlanFairValueOfPlanAssets	6.0	65.9	61.0	46.9

us-gaap:DefinedBenefitPlanEquitySecurities, us-gaap:FairValueInputsLevel1

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	1.719	1.796	1.361	1.031
Percentage of DefinedBenefitPlanFairValueOfPlanAssets	1.7	2.3	1.9	2.1

us-gaap:DefinedBenefitPlanEquitySecurities, us-gaap:FairValueInputsLevel2

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	6.904	0.0	0.0	0.0
Percentage of DefinedBenefitPlanFairValueOfPlanAssets	6.9	0.0	0.0	0.0

us-gaap:DefinedBenefitPlanFairValueOfPlanAssets us-gaap:FairValueByFairValueHierarchyLevel

us-gaap:FairValueInputsLevel1

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31
Value	8.537	6.718	5.399	9.292	8.638	11	20	14	1.143	0.675
Percentage of DefinedBenefitPlanFairValueOfPlanAssets	8.5	8.6	7.6	19.3	20.5	26.2	14.3	11.3	1.3	0.7

us-gaap:FairValueInputsLevel2

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31
Value	32	0.0	0.0	0.0	33	32	121	111	87	91
Percentage of DefinedBenefitPlanFairValueOfPlanAssets	31.9	0.0	0.0	0.0	79.5	73.8	85.7	88.7	98.7	99.3

us-gaap:FairValueInputsLevel3

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	53	0.609	0.632	0.0
Percentage of DefinedBenefitPlanFairValueOfPlanAssets	53.5	0.8	0.9	0.0

us-gaap:FairValueMeasuredAtNetAssetValuePerShare

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	6.078	71	64	38
Percentage of DefinedBenefitPlanFairValueOfPlanAssets	6.0	90.7	91.5	80.7

us-gaap:DefinedBenefitPlanFairValueOfPlanAssets us-gaap:RetirementPlanType

us-gaap:PensionPlansDefinedBenefit

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31	2016-01-02
Value	100	78	70	48	42	44
Percentage of DefinedBenefitPlanFairValueOfPlanAssets	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:DefinedBenefitPlanFundedStatusOfPlan us-gaap:RetirementPlanType

us-gaap:DefinedBenefitPlanFundedStatusOfPlan

us-gaap:PensionPlansDefinedBenefit

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31
Value	-48514000.0	-38419000.0	-32157000.0	-19145000.0	-13398000.0
Percentage of DefinedBenefitPlanFundedStatusOfPlan	100.0	100.0	100.0	100.0	100.0

us-gaap:DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsPlanAssets

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	100	42	37	9.292
Percentage of DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsPlanAssets	100.0	100.0	100.0	100.0

us-gaap:DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsProjectedBenefitObligation

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	148	81	70	28
Percentage of DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsProjectedBenefitObligation	100.0	100.0	100.0	100.0

us-gaap:DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31
Value	130	75	66	18	51
Percentage of DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation	100.0	100.0	100.0	100.0	100.0

us-gaap:DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31
Value	92	42	36	6.003	38
Percentage of DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets	100.0	100.0	100.0	100.0	100.0

us-gaap:DefinedBenefitPlanWeightedAverageAssetAllocations

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	100.0	1.0	1.0	1.0
Percentage of DefinedBenefitPlanWeightedAverageAssetAllocations	100.0	100.0	100.0	100.0

us-gaap:DefinedBenefitPlanWeightedAverageAssetAllocations us-gaap:DefinedBenefitPlanByPlanAssetCategories

lfus:BulkAnnuityContract

Period End	2020-12-26
Value	53.0
Percentage of DefinedBenefitPlanWeightedAverageAssetAllocations	53.0

us-gaap:DefinedBenefitPlanCashAndCashEquivalents

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	7.0	0.01	0.04	0.01
Percentage of DefinedBenefitPlanWeightedAverageAssetAllocations	7.0	1.0	4.0	1.0

us-gaap:DefinedBenefitPlanEquitySecurities

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	9.0	0.27	0.3	0.35
Percentage of DefinedBenefitPlanWeightedAverageAssetAllocations	9.0	27.0	30.0	35.0

us-gaap:FixedIncomeSecurities

Period End	2020-12-26	2019-12-28
Value	31.0	72.0
Percentage of DefinedBenefitPlanWeightedAverageAssetAllocations	31.0	7200.0

us-gaap:EmployeeRelatedLiabilitiesCurrent

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-07-02	2016-04-02	2016-01-02	2015-09-26	2015-06-27	2015-03-28	2014-12-27	2014-09-27	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-10-01	2011-07-02	2011-01-01
Value	64	45	50	49	40	32	40	42	36	38	60	52	43	41	49	42	32	24	42	39	30	28	32	31	25	20	30	28	22	16	29	26	19	13	20	20	21	15	23	21	18	24
Percentage of EmployeeRelatedLiabilitiesCurrent	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized

Period End	2020-12-26
Value	22
Percentage of EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized	100.0

us-gaap:EquityMethodInvestmentOwnershipPercentage us-gaap:ScheduleOfEquityMethodInvestmentEquityMethodInvesteeName

us-gaap:EquityMethodInvestmentOwnershipPercentage

lfus:ATEC

Period End	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	24.0	0.24	0.24	0.24	0.24	0.24	0.24	0.24	0.24	0.24	0.24
Percentage of EquityMethodInvestmentOwnershipPercentage	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

lfus:EBTech

Period End	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	19.0	0.19	0.19	0.19	0.19	0.19	0.2	0.2	0.2	0.2	0.2
Percentage of EquityMethodInvestmentOwnershipPercentage	79.2	79.2	79.2	79.2	79.2	79.2	83.3	83.3	83.3	83.3	83.3

lfus:Powersem

Period End	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31
Value	45.0	0.45	0.45	0.45	0.45	0.45	0.45	0.45	0.45	0.45	0.45
Percentage of EquityMethodInvestmentOwnershipPercentage	187.5	187.5	187.5	187.5	187.5	187.5	187.5	187.5	187.5	187.5	187.5

us-gaap:EquityMethodInvestmentQuotedMarketValue

Period End	2103-03-30	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2011-12-31
Value	9100000.0	8300000.0	8600000.0	9100000.0	7800000.0	8400000.0	9200000.0	6800000.0
Percentage of EquityMethodInvestmentQuotedMarketValue	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:EquityMethodInvestments

Period End	2020-12-26	2019-12-28	2018-12-29
Value	11	11	11
Percentage of EquityMethodInvestments	100.0	100.0	100.0

us-gaap:EquitySecuritiesFvNiCost

Period End	2020-09-26
Value	500000.0
Percentage of EquitySecuritiesFvNiCost	100.0

us-gaap:FiniteLivedIntangibleAssetsAccumulatedAmortization

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-31	2013-12-28	2012-12-31	2012-12-29	2011-12-31
Value	291	279	271	256	243	230	223	226	216	206	196	183	170	159	146	122	100	90	81	81	70	70	65
Percentage of FiniteLivedIntangibleAssetsAccumulatedAmortization	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:FiniteLivedIntangibleAssetsAccumulatedAmortization us-gaap:FiniteLivedIntangibleAssetsByMajorClass

lfus:CustomerListsTrademarksAndTradeNames

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2016-12-31	2016-01-02
Value	151	143	137	128	119	111	106	113	105	99	92	69	63	59	53	40	30
Percentage of FiniteLivedIntangibleAssetsAccumulatedAmortization	52.0	51.4	50.7	50.0	49.3	48.5	47.7	50.2	48.9	48.1	47.0	37.8	37.2	37.4	36.6	33.1	30.3

lfus:PatentsLicensesAndSoftware

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-31	2013-12-28	2012-12-31	2012-12-29	2011-12-31
Value	97	94	92	88	83	80	78	76	75	72	69	71	67	64	59	48	41	38	37	37	32	32	31
Percentage of FiniteLivedIntangibleAssetsAccumulatedAmortization	33.6	33.8	34.2	34.4	34.6	34.9	35.3	33.9	34.7	35.0	35.4	38.9	39.7	40.1	40.7	39.3	40.8	42.6	46.6	46.6	46.4	46.4	47.8

us-gaap:DistributionRights

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-31	2013-12-28	2012-12-31	2012-12-29	2011-12-31
Value	39	39	38	38	37	36	36	36	35	35	34	34	33	33	33	30	29	27	29	24	26	28	25
Percentage of FiniteLivedIntangibleAssetsAccumulatedAmortization	13.7	14.1	14.4	14.9	15.3	15.8	16.2	15.9	16.5	17.0	17.6	18.6	19.7	21.0	22.8	24.7	28.9	30.2	35.8	30.6	37.9	40.0	39.0

us-gaap:UseRights

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2018-12-29
Value	2.177	2.051	2.007	1.895	1.8	1.755	1.73	1.168
Percentage of FiniteLivedIntangibleAssetsAccumulatedAmortization	0.7	0.7	0.7	0.7	0.7	0.8	0.8	0.6

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive

Period End	2020-12-26
Value	122
Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive	100.0

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26
Value	40	40	38	38
Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	100.0	100.0	100.0	100.0

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear

Period End	2021-06-26	2021-03-27	2020-09-26
Value	41	41	41
Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseRemainderOfFiscalYear	100.0	100.0	100.0

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearFive

Period End	2020-12-26
Value	29
Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	100.0

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearFour

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26
Value	32	32	30	29
Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	100.0	100.0	100.0	100.0

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearThree

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26
Value	33	33	33	32
Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	100.0	100.0	100.0	100.0

us-gaap:FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26
Value	36	36	37	37
Percentage of FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	100.0	100.0	100.0	100.0

us-gaap:FiniteLivedIntangibleAssetsGross

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2016-12-31	2012-12-29	2011-12-31
Value	599	596	563	552	544	539	544	552	557	556	557	561	560	564	350	331	119	109
Percentage of FiniteLivedIntangibleAssetsGross	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:FiniteLivedIntangibleAssetsGross us-gaap:FiniteLivedIntangibleAssetsByMajorClass

lfus:CustomerListsTrademarksAndTradeNames

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2016-12-31
Value	401	400	372	365	360	357	360	372	374	374	374	312	311	314	162	150
Percentage of FiniteLivedIntangibleAssetsGross	67.0	67.1	66.0	66.1	66.2	66.2	66.2	67.4	67.1	67.2	67.1	55.7	55.6	55.7	46.4	45.5

lfus:PatentsLicensesAndSoftware

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2016-12-31	2012-12-29	2011-12-31
Value	143	142	137	133	131	129	131	136	139	138	139	192	192	193	141	131	43	41
Percentage of FiniteLivedIntangibleAssetsGross	24.0	23.9	24.4	24.2	24.1	24.0	24.1	24.7	25.0	24.9	25.0	34.3	34.3	34.3	40.4	39.7	36.8	38.2

us-gaap:DistributionRights

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2016-12-31	2012-12-29	2011-12-31
Value	43	43	43	43	43	43	43	43	43	43	43	44	44	44	46	49	47	44
Percentage of FiniteLivedIntangibleAssetsGross	7.3	7.3	7.8	7.9	7.9	8.0	7.9	7.9	7.9	7.9	7.9	7.9	7.9	7.9	13.2	14.8	39.5	40.7

us-gaap:UseRights

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2018-12-29
Value	10	10	10	9.913	9.584	9.545	9.649	6.792
Percentage of FiniteLivedIntangibleAssetsGross	1.7	1.7	1.8	1.8	1.8	1.8	1.8	1.2

us-gaap:GoodwillGross

Period End	2021-06-26	2021-03-27	2020-12-26	2019-12-28	2018-12-29
Value	896	890	862	829	835
Percentage of GoodwillGross	100.0	100.0	100.0	100.0	100.0

us-gaap:GoodwillGross us-gaap:StatementBusinessSegments

lfus:Automotive

Period End	2020-12-26	2019-12-28	2018-12-29
Value	138	131	132
Percentage of GoodwillGross	16.0	15.8	15.8

lfus:AutomotiveSegment

Period End	2021-06-26	2021-03-27	2020-12-26
Value	136	136	138
Percentage of GoodwillGross	15.3	15.3	16.0

lfus:Electronics

Period End	2020-12-26	2019-12-28	2018-12-29
Value	676	650	656
Percentage of GoodwillGross	78.4	78.5	78.5

lfus:ElectronicsSegment

Period End	2021-06-26	2021-03-27	2020-12-26
Value	671	668	676
Percentage of GoodwillGross	74.9	75.0	78.4

lfus:Industrial

Period End	2020-12-26	2019-12-28	2018-12-29
Value	47	47	46
Percentage of GoodwillGross	5.5	5.7	5.6

lfus:IndustrialSegment

Period End	2021-06-26	2021-03-27	2020-12-26
Value	88	86	47
Percentage of GoodwillGross	9.8	9.7	5.5

us-gaap:GoodwillImpairedAccumulatedImpairmentLoss

Period End	2021-06-26	2021-03-27	2020-12-26	2019-12-28	2018-12-29	2016-01-02	2015-09-28	2014-12-27	2013-12-28	2012-12-29	2011-12-31
Value	45	45	45	8.794	8.486	0.0	0.0	0.0	0.0	0.0	0.0
Percentage of GoodwillImpairedAccumulatedImpairmentLoss	100.0	100.0	100.0	100.0	100.0	0.0	0.0	0.0	0.0	0.0	0.0

us-gaap:GoodwillImpairedAccumulatedImpairmentLoss us-gaap:StatementBusinessSegments

lfus:Automotive

Period End	2020-12-26
Value	36
Percentage of GoodwillImpairedAccumulatedImpairmentLoss	80.2

lfus:AutomotiveSegment

Period End	2021-06-26	2021-03-27	2020-12-26
Value	36	36	36
Percentage of GoodwillImpairedAccumulatedImpairmentLoss	80.1	80.1	80.2

lfus:Industrial

Period End	2020-12-26	2019-12-28	2018-12-29
Value	8.995	8.794	8.486
Percentage of GoodwillImpairedAccumulatedImpairmentLoss	19.8	100.0	100.0

us-gaap:IncomeTaxExaminationInterestAccrued

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31	2016-01-02	2014-12-27
Value	8800000.0	7200000.0	5900000.0	3300000.0	2400000.0	1500000.0	1300000.0
Percentage of IncomeTaxExaminationInterestAccrued	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:InterestAndDividendsPayableCurrent

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2017-12-30
Value	4506000.0	2636000.0	4517000.0	2747000.0	4781000.0	3159000.0	5058000.0	3239000.0	4366000.0	2487000.0	5137000.0	2477000.0
Percentage of InterestAndDividendsPayableCurrent	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:InventoryRawMaterials

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2011-12-31
Value	111	97	85	81	82	75	76	28	29	28	39	26	21	21	26	25	26
Percentage of InventoryRawMaterials	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:InventoryValuationReserves

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28
Value	35	35	34	33	33	32	34
Percentage of InventoryValuationReserves	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:InventoryWorkInProcess

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2014-06-28	2014-03-29	2013-12-28	2013-09-28	2013-06-29	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2011-12-31
Value	106	102	92	90	92	84	84	18	18	17	17	15	12	11	13	16	10
Percentage of InventoryWorkInProcess	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths

Period End	2020-12-26
Value	7660000.0
Percentage of LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	100.0

us-gaap:LineOfCreditFacilityRemainingBorrowingCapacity us-gaap:CreditFacility, us-gaap:DebtInstrument

us-gaap:LineOfCreditFacilityRemainingBorrowingCapacity

us-gaap:RevolvingCreditFacility, lfus:CreditAgreement

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2016-12-31
Value	600	571	383	245	462
Percentage of LineOfCreditFacilityRemainingBorrowingCapacity	100.0	100.0	100.0	100.0	100.0

us-gaap:LongTermDebtFairValue us-gaap:DebtInstrument, us-gaap:FairValueByMeasurementBasis, us-gaap:LongtermDebtType

us-gaap:LongTermDebtFairValue

lfus:EuroSeniorNotesSeriesA, us-gaap:CarryingReportedAmountFairValueDisclosure, us-gaap:SeniorNotes

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2019-12-28
Value	139	138	142	136	129
Percentage of LongTermDebtFairValue	100.0	100.0	100.0	100.0	100.0

lfus:EuroSeniorNotesSeriesA, us-gaap:EstimateOfFairValueFairValueDisclosure, us-gaap:SeniorNotes

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2019-12-28
Value	141	140	144	136	131
Percentage of LongTermDebtFairValue	101.5	101.5	101.2	100.2	101.5

lfus:EuroSeniorNotesSeriesB, us-gaap:CarryingReportedAmountFairValueDisclosure, us-gaap:SeniorNotes

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2019-12-28
Value	113	112	115	110	105
Percentage of LongTermDebtFairValue	81.2	81.2	81.2	81.2	81.2

lfus:EuroSeniorNotesSeriesB, us-gaap:EstimateOfFairValueFairValueDisclosure, us-gaap:SeniorNotes

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2019-12-28
Value	119	117	123	114	110
Percentage of LongTermDebtFairValue	85.6	85.3	86.6	84.3	85.0

lfus:USSeniorNotesSeriesADue2022, us-gaap:EstimateOfFairValueFairValueDisclosure, us-gaap:SeniorNotes

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2019-12-28
Value	25	25	25	25	25
Percentage of LongTermDebtFairValue	18.1	18.4	17.8	18.7	19.3

lfus:USSeniorNotesSeriesADue2025, us-gaap:EstimateOfFairValueFairValueDisclosure, us-gaap:SeniorNotes

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2019-12-28
Value	52	52	53	53	50
Percentage of LongTermDebtFairValue	37.9	38.3	37.5	39.1	39.1

lfus:USSeniorNotesSeriesBDue2027, us-gaap:EstimateOfFairValueFairValueDisclosure, us-gaap:SeniorNotes

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2019-12-28
Value	107	106	109	109	102
Percentage of LongTermDebtFairValue	76.9	76.9	76.8	80.2	79.0

lfus:USSeniorNotesSeriesBDue2030, us-gaap:EstimateOfFairValueFairValueDisclosure, us-gaap:SeniorNotes

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2019-12-28
Value	134	130	138	138	127
Percentage of LongTermDebtFairValue	96.1	94.7	96.7	101.4	98.4

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive

Period End	2020-12-26
Value	340
Percentage of LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive	100.0

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive

Period End	2020-12-26
Value	180
Percentage of LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive	100.0

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree

Period End	2020-12-26
Value	142
Percentage of LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree	100.0

us-gaap:LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo

Period End	2020-12-26
Value	27
Percentage of LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo	100.0

us-gaap:LossContingencyAccrualCarryingValueNoncurrent

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31	2016-01-02	2014-12-27	2013-12-28	2012-12-29	2011-12-31
Value	2300000.0	600000.0	1100000.0	900000.0	1400000.0	1800000.0	1900000.0	2200000.0	2400000.0	3100000.0
Percentage of LossContingencyAccrualCarryingValueNoncurrent	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:MarketableSecurities us-gaap:BalanceSheetLocation

us-gaap:MarketableSecurities

us-gaap:OtherNoncurrentAssets

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30
Value	13	10	9.1	8.0
Percentage of MarketableSecurities	100.0	100.0	100.0	100.0

us-gaap:OperatingLeaseWeightedAverageDiscountRatePercent

Period End	2020-12-26	2019-12-28
Value	5.06	5.11
Percentage of OperatingLeaseWeightedAverageDiscountRatePercent	100.0	100.0

us-gaap:PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2015-06-27	2015-03-28	2014-12-27
Value	2.751	1.106	1.094	0.481	11	11	11
Percentage of PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:PrepaidTaxes

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2017-09-30	2017-07-01	2017-04-01	2016-12-31	2016-10-01	2016-01-02
Value	3.961	4.146	3.029	1.218	1.529	4.253	4.831	2.73	1.374	0.758	2.339	6.802	4.648	3.899	1.689	6.658	6.72	12	11	14	1.51
Percentage of PrepaidTaxes	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount us-gaap:ReportingUnit

us-gaap:ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount

lfus:CommercialVehicleProducts

Period End	2020-09-27
Value	137.0
Percentage of ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount	100.0

lfus:ElectronicsNonSiliconUnit

Period End	2020-09-27
Value	218.0
Percentage of ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount	159.1

lfus:ElectronicsSiliconUnit

Period End	2020-09-27
Value	44.0
Percentage of ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount	32.1

lfus:FuseUnit

Period End	2020-09-27
Value	210.0
Percentage of ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount	153.3

lfus:PassengerCar

Period End	2020-09-27
Value	160.0
Percentage of ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount	116.8

lfus:RelayUnit

Period End	2020-09-27
Value	139.0
Percentage of ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount	101.5

lfus:Sensors

Period End	2020-09-27
Value	59.0
Percentage of ReportingUnitPercentageOfFairValueInExcessOfCarryingAmount	43.1

us-gaap:RestrictedCashAndCashEquivalentsAtCarryingValue

Period End	2021-06-26	2021-03-27
Value	3790000.0	3462000.0
Percentage of RestrictedCashAndCashEquivalentsAtCarryingValue	100.0	100.0

us-gaap:RestrictedCashNoncurrent

Period End	2021-06-26	2021-03-27
Value	1734000.0	1064000.0
Percentage of RestrictedCashNoncurrent	100.0	100.0

us-gaap:RestructuringReserve

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2017-12-30	2013-03-30	2012-12-29	2012-09-29	2012-06-30	2012-03-31	2011-12-31	2011-01-01	2010-01-02
Value	2.9	2.6	4.2	4.5	4.5	3.3	2.7	2.3	4.8	2.1	3.9	1.5	0.523	0.645	0.981	1.303	1.516	1.441	3.765	10
Percentage of RestructuringReserve	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:RestructuringReserveCurrent

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30	2016-12-31
Value	1109000.0	2588000.0	4195000.0	4542000.0	4463000.0	3336000.0	2679000.0	2302000.0	4753000.0	2144000.0	3887000.0	901000.0	1049000.0	1367000.0	1459000.0	2785000.0
Percentage of RestructuringReserveCurrent	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:RestructuringReserveNoncurrent

Period End	2021-06-26
Value	1800000.0
Percentage of RestructuringReserveNoncurrent	100.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice

Period End	2020-12-26
Value	133.0
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice	100.0

us-gaap:ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue

Period End	2020-12-26
Value	69
Percentage of ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue	100.0

us-gaap:SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1

Period End	2020-12-26
Value	35
Percentage of SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1	100.0

us-gaap:TradingSecuritiesDebt

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30
Value	14	13	13	11	10	8.769	10	9.717	9.619	9.806	9.112	10	9.95	9.852	7.962
Percentage of TradingSecuritiesDebt	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:TradingSecuritiesDebt us-gaap:FairValueByFairValueHierarchyLevel

us-gaap:FairValueInputsLevel1

Period End	2021-06-26	2021-03-27	2020-12-26	2020-09-26	2020-06-27	2020-03-28	2019-12-28	2019-09-28	2019-06-29	2019-03-30	2018-12-29	2018-09-29	2018-06-30	2018-03-31	2017-12-30
Value	14	13	13	11	10	8.769	10	9.717	9.619	9.806	9.112	10	9.95	9.852	7.962
Percentage of TradingSecuritiesDebt	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:UndistributedEarningsOfForeignSubsidiaries

Period End	2020-12-26
Value	767
Percentage of UndistributedEarningsOfForeignSubsidiaries	100.0

us-gaap:ValuationAllowancesAndReservesBalance us-gaap:ValuationAllowancesAndReservesType

us-gaap:ValuationAllowancesAndReservesBalance

lfus:SECSchedule1209ReserveSalesDiscountsandAllowances

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31	2016-01-02
Value	43	40	34	26	23	17
Percentage of ValuationAllowancesAndReservesBalance	100.0	100.0	100.0	100.0	100.0	100.0

us-gaap:AllowanceForCreditLoss

Period End	2020-12-26	2019-12-28	2018-12-29	2017-12-30	2016-12-31	2016-01-02
Value	1.4	1.31	1.062	1.172	2.079	0.319
Percentage of ValuationAllowancesAndReservesBalance	3.2	3.2	3.0	4.4	8.7	1.9

Line plots across dimensions of each concept

TTM Greenblatt ROC
_
(None,)

us-gaap:OperatingIncomeLoss
us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments
('us-gaap:OperatingSegments', None)

us-gaap:OtherComprehensiveIncomeLossNetOfTax
us-gaap:StatementEquityComponents
(None,)

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax
us-gaap:ProductOrService, us-gaap:StatementBusinessSegments
('lfus:IndustrialProducts', None)

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax
us-gaap:ProductOrService
(None,)

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax
us-gaap:StatementBusinessSegments
(None,)

us-gaap:RevenueFromContractWithCustomerIncludingAssessedTax
us-gaap:StatementGeographical
(None,)

us-gaap:NoncurrentAssets
us-gaap:StatementGeographical
(None,)

us-gaap:PropertyPlantAndEquipmentGross
us-gaap:PropertyPlantAndEquipmentByType
(None,)

us-gaap:Goodwill
us-gaap:StatementBusinessSegments
(None,)

us-gaap:FiniteLivedIntangibleAssetsNet
us-gaap:FiniteLivedIntangibleAssetsByMajorClass
(None,)

us-gaap:StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest
us-gaap:StatementEquityComponents
(None,)

us-gaap:DepreciationDepletionAndAmortization
us-gaap:StatementBusinessSegments
(None,)

LFUS

Table of contents

Plots across concepts

Tables

Common Stock Value

us-gaap:CommonStockValue

us-gaap:CommonStockValue

Weighted Average Number Of Diluted Shares Outstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

us-gaap:WeightedAverageNumberOfDilutedSharesOutstanding

Weighted Average Number Of Shares Outstanding Basic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

us-gaap:WeightedAverageNumberOfSharesOutstandingBasic

Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount

us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount

us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount

us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount us-gaap:AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecurities

us-gaap:EmployeeStockOption

Earnings Per Share Basic

us-gaap:EarningsPerShareBasic

us-gaap:EarningsPerShareBasic

Earnings Per Share Diluted

us-gaap:EarningsPerShareDiluted

us-gaap:EarningsPerShareDiluted

Comprehensive Income Net Of Tax

us-gaap:ComprehensiveIncomeNetOfTax

us-gaap:ComprehensiveIncomeNetOfTax

Cost Of Goods And Services Sold

us-gaap:CostOfGoodsAndServicesSold

us-gaap:CostOfGoodsAndServicesSold

us-gaap:CostOfGoodsAndServicesSold us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceIncludingPortionAttributableToNoncontrollingInterest

Cost Of Revenue

us-gaap:CostOfRevenue

us-gaap:CostOfRevenue

Gross Profit

us-gaap:GrossProfit

us-gaap:GrossProfit

Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

us-gaap:IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest

Income Tax Expense Benefit

us-gaap:IncomeTaxExpenseBenefit

us-gaap:IncomeTaxExpenseBenefit

Interest Expense

us-gaap:InterestExpense

us-gaap:InterestExpense

Interest Expense Debt

us-gaap:InterestExpenseDebt

us-gaap:InterestExpenseDebt

Operating Expenses

us-gaap:OperatingExpenses

us-gaap:OperatingExpenses

Operating Income Loss

us-gaap:OperatingIncomeLoss

us-gaap:OperatingIncomeLoss

us-gaap:OperatingIncomeLoss us-gaap:ConsolidationItems, us-gaap:StatementBusinessSegments

us-gaap:CorporateNonSegment, us-gaap:AllOtherSegments

us-gaap:OperatingSegments, lfus:Automotive

us-gaap:OperatingSegments, lfus:AutomotiveSegment

us-gaap:OperatingSegments, lfus:Electronics

us-gaap:OperatingSegments, lfus:ElectronicsSegment

us-gaap:OperatingSegments, lfus:Industrial

us-gaap:OperatingSegments, lfus:IndustrialSegment

Other Comprehensive Income Loss Net Of Tax

us-gaap:OtherComprehensiveIncomeLossNetOfTax

us-gaap:OtherComprehensiveIncomeLossNetOfTax

us-gaap:OtherComprehensiveIncomeLossNetOfTax us-gaap:StatementEquityComponents

us-gaap:AccumulatedDefinedBenefitPlansAdjustment

us-gaap:AccumulatedOtherComprehensiveIncome

us-gaap:AccumulatedTranslationAdjustment

Other Income

us-gaap:OtherIncome us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:StatementEquityComponents

us-gaap:OtherIncome

us-gaap:ReclassificationOutOfAccumulatedOtherComprehensiveIncome, us-gaap:AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceIncludingPortionAttributableToNoncontrollingInterest

Other Nonoperating Income Expense

us-gaap:OtherNonoperatingIncomeExpense

us-gaap:OtherNonoperatingIncomeExpense

Profit Loss

us-gaap:ProfitLoss