CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) (Unaudited) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Oct. 06, 2018	Oct. 07, 2017	Oct. 06, 2018	Oct. 07, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net earnings (loss)	$ 17,465	$ (123,506)	$ 47,580	$ (87,452)
Other comprehensive income, before tax
Pension and postretirement liability adjustment	83	31	278	103
Income tax expense related to items of other comprehensive income	(20)	(12)	(68)	(39)
Total other comprehensive income, after tax	63	19	210	64
Comprehensive income (loss)	$ 17,528	$ (123,487)	$ 47,790	$ (87,388)

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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