Quarterly Financial Information (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended									12 Months Ended
	Jan. 03, 2021		Oct. 04, 2020	Jul. 05, 2020	Apr. 05, 2020	Dec. 29, 2019	Sep. 29, 2019	Jun. 30, 2019	Mar. 31, 2019	Jan. 03, 2021	Dec. 29, 2019	Dec. 30, 2018
Quarterly Financial Data [Abstract]
Revenue	$ 1,354,606		$ 964,025	$ 811,718	$ 652,396	$ 805,496	$ 706,923	$ 722,517	$ 648,737	$ 3,782,745	$ 2,883,673
Gross profit	827,065		527,445	447,344	308,023	398,181	342,275	347,793	307,806	2,109,877	1,396,055
Restructuring and other costs, net	(3,062)		4,059	1,158	5,858	1,560	14,068	6,161	7,639	8,013	29,428	$ 11,144
Operating income from continuing operations	510,254	[1]	248,006	175,639	44,682	138,248	78,660	91,735	53,330	978,581	361,973	323,884
Income from continuing operations before income taxes	473,091	[1]	233,757	164,827	34,689	65,296	63,254	71,827	36,765	906,364	237,142	257,683
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Parent	(73)		(37)	(51)	(50)	(48)	(52)	(54)	(41)	(211)	(195)	452
Operating income from continuing operations	380,434	[1]	176,736	137,213	33,715	64,549	58,610	69,141	35,453	728,098	227,753	237,475
Net income	$ 380,361	[1]	$ 176,699	$ 137,162	$ 33,665	$ 64,501	$ 58,558	$ 69,087	$ 35,412	$ 727,887	$ 227,558	$ 237,927
Basic earnings per share:
Income from continuing operations	$ 3.40	[1]	$ 1.58	$ 1.23	$ 0.30	$ 0.58	$ 0.53	$ 0.62	$ 0.32	$ 6.53	$ 2.06	$ 2.15
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share	(0.00)		(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	0.00
Net income	3.40	[1]	1.58	1.23	0.30	0.58	0.53	0.62	0.32	6.53	2.06	2.15
Diluted earnings per share:
Income from continuing operations	3.38	[1]	1.57	1.23	0.30	0.58	0.53	0.62	0.32	6.50	2.04	2.13
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share	(0.00)		(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	(0.00)	0.00
Net income	3.38	[1]	1.57	1.23	0.30	0.58	0.52	0.62	0.32	6.49	2.04	$ 2.13
Cash dividends per common share	$ 0.07		$ 0.07	$ 0.07	$ 0.07	$ 0.07	$ 0.07	$ 0.07	$ 0.07	$ 0.28	$ 0.28
Defined Benefit Plan, Recognized Net Gain (Loss) on Mark-to-Market										$ 25,400	$ 31,200
Tax Adjustments, Settlements, and Unusual Provisions										10,800	(23,400)	$ (8,100)
Diagnostics [Member]
Quarterly Financial Data [Abstract]
Operating income from continuing operations										$ 874,206	$ 189,330	$ 153,196

[1] The fourth quarter of fiscal year 2020 includes a pre-tax loss of $25.4 million as a result of the mark-to-market adjustment on postretirement benefit plans. The fourth quarter of fiscal year 2019 includes a pre-tax loss of $31.2 million as a result of the mark-to-market adjustment on postretirement benefit plans. See Note 1 for a discussion of this accounting policy