Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jul. 17, 2021	Jul. 11, 2020	Jul. 17, 2021	Jul. 11, 2020
Statement Of Income And Comprehensive Income [Abstract]
Net income		$ 56,358	$ 57,919	$ 128,013	$ 52,147
Pension and postretirement plans:
Settlement and curtailment loss					86,865
Net loss for the period					15,693
Amortization of prior service cost included in net income		9	9	22	64
Amortization of actuarial loss included in net income		92	43	215	996
Pension and postretirement plans, net of tax		101	52	237	103,618
Derivative instruments:
Net change in fair value of derivatives	[1]	(4,342)	(3,358)	403	(7,207)
(Gain) loss reclassified to net income		(594)	664	(374)	1,075
Derivative instruments, net of tax		(4,936)	(2,694)	29	(6,132)
Other comprehensive (loss) income, net of tax		(4,835)	(2,642)	266	97,486
Comprehensive income		$ 51,523	$ 55,277	$ 128,279	$ 149,633

[1] Amounts in parentheses indicate debits to determine net income.