Supplemental Stockholders' Equity Information - Changes in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2021	Mar. 29, 2020
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance, beginning of period	$ 1,328,111	$ 1,173,863
Income tax (benefit)/expense	709	1,915
Other comprehensive income, net of tax	1,928	4,943
Balance, end of period	1,355,462	1,193,574
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance, beginning of period	8,386
Other comprehensive income before reclassifications, before tax	(2,702)
Amounts reclassified from accumulated other comprehensive loss, before tax	0
Income tax (benefit)/expense	(723)
Other comprehensive income, net of tax	(1,979)
Balance, end of period	6,407
Funded Status of Benefit Plans
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance, beginning of period	(421,698)
Other comprehensive income before reclassifications, before tax	0
Amounts reclassified from accumulated other comprehensive loss, before tax	6,406
Income tax (benefit)/expense	1,718
Other comprehensive income, net of tax	4,688
Balance, end of period	(417,010)
Net Unrealized Gain on Available-For-Sale Securities
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance, beginning of period	3,131
Other comprehensive income before reclassifications, before tax	(1,067)
Amounts reclassified from accumulated other comprehensive loss, before tax	0
Income tax (benefit)/expense	(286)
Other comprehensive income, net of tax	(781)
Balance, end of period	2,350
Total Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance, beginning of period	(410,181)	(494,976)
Other comprehensive income before reclassifications, before tax	(3,769)
Amounts reclassified from accumulated other comprehensive loss, before tax	6,406
Income tax (benefit)/expense	709
Other comprehensive income, net of tax	1,928	4,943
Balance, end of period	$ (408,253)	$ (490,033)