CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME/(LOSS) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 26, 2022	Jun. 30, 2023	Jun. 26, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 46,574	$ 61,777	$ 68,895	$ 66,502
Other comprehensive income/(loss), before tax:
Gain/(Loss) on foreign currency translation adjustments	286	(3,407)	1,134	(5,616)
Pension and postretirement benefits obligation	1,553	5,114	3,106	10,124
Net unrealized gain/(loss) on available-for-sale securities	1,496	(1,911)	4,098	(9,827)
Other comprehensive income/(loss), before tax	3,335	(204)	8,338	(5,319)
Income tax expense/(benefit)	879	(104)	2,173	(1,484)
Other comprehensive income/(loss), net of tax	2,456	(100)	6,165	(3,835)
Comprehensive income attributable to common stockholders	$ 49,030	$ 61,677	$ 75,060	$ 62,667