Supplemental Stockholders' Equity Information - Changes in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 26, 2021	Sep. 27, 2020	Sep. 26, 2021	Sep. 27, 2020
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance, beginning of period	$ 1,418,787	$ 1,231,031	$ 1,328,111	$ 1,173,863
Income tax (benefit)/expense	1,067	2,192	3,532	6,955
Other comprehensive income, net of tax	2,914	6,038	9,651	19,058
Balance, end of period	1,469,532	1,257,254	1,469,532	1,257,254
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance, beginning of period			8,386
Other comprehensive income before reclassifications, before tax			(3,421)
Amounts reclassified from accumulated other comprehensive loss, before tax			0
Income tax (benefit)/expense			(914)
Other comprehensive income, net of tax			(2,507)
Balance, end of period	5,879		5,879
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			19,220
Income tax (benefit)/expense			5,146
Other comprehensive income, net of tax			14,074
Balance, end of period	(407,624)		(407,624)
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			(2,616)
Amounts reclassified from accumulated other comprehensive loss, before tax			0
Income tax (benefit)/expense			(700)
Other comprehensive income, net of tax			(1,916)
Balance, end of period	1,215		1,215
Total Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Balance, beginning of period	(403,444)	(481,956)	(410,181)	(494,976)
Other comprehensive income before reclassifications, before tax			(6,037)
Amounts reclassified from accumulated other comprehensive loss, before tax			19,220
Income tax (benefit)/expense			3,532
Other comprehensive income, net of tax	2,914	6,038	9,651	19,058
Balance, end of period	$ (400,530)	$ (475,918)	$ (400,530)	$ (475,918)