Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jul. 14, 2018	Jul. 15, 2017	Jul. 14, 2018	Jul. 15, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 45,442	$ 44,740	$ 96,689	$ 105,158
Pension and postretirement plans:
Settlement loss	773		4,263
Net gain for the period	3,943		12,756
Amortization of prior service cost included in net income	35	25	61	58
Amortization of actuarial loss included in net income	865	833	1,941	1,943
Pension and postretirement plans, net of tax	5,616	858	19,021	2,001
Derivative instruments:
Net change in fair value of derivatives	(8,809)	7,238	1,661	3,720
Loss reclassified to net income	126	320	423	794
Derivative instruments, net of tax	(8,683)	7,558	2,084	4,514
Other comprehensive income (loss), net of tax	(3,067)	8,416	21,105	6,515
Comprehensive income	$ 42,375	$ 53,156	$ 117,794	$ 111,673

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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