Changes in Accumulated Other Comprehensive (Loss) Income (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	$ 1,550,673	$ 1,470,228	$ 1,480,158	$ 1,522,354
Other comprehensive income	18,613	8,115	10,354	5,449
Balance	1,744,551	1,479,412	1,744,551	1,479,412
Foreign Currency Translation Reclassification Adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			(23,514)	(12,523)
Other comprehensive loss before reclassifications, net of tax			7,026	983
Amounts reclassified from accumulated other comprehensive income (loss), net of tax			0	0
Other comprehensive income			7,026	983
Balance	(16,488)	(11,540)	(16,488)	(11,540)
Unrealized Gains (Losses) on Marketable Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			3,480	(1,845)
Other comprehensive loss before reclassifications, net of tax			4,830	4,637
Amounts reclassified from accumulated other comprehensive income (loss), net of tax			(1,499)	(97)
Other comprehensive income			3,331	4,540
Balance	6,811	2,695	6,811	2,695
Amortization of Prior Service Credit
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance			1,180	1,328
Other comprehensive loss before reclassifications, net of tax			0	0
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(2)	(37)	(3)	(74)
Other comprehensive income			(3)	(74)
Balance	1,177	1,254	1,177	1,254
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(27,113)	(15,706)	(18,854)	(13,040)
Other comprehensive loss before reclassifications, net of tax			11,856	5,620
Amounts reclassified from accumulated other comprehensive income (loss), net of tax	(985)	(64)	(1,502)	(171)
Other comprehensive income	18,613	8,115	10,354	5,449
Balance	$ (8,500)	$ (7,591)	$ (8,500)	$ (7,591)