Recent Accounting Pronouncements - Summary of Reclassification of Tax Effects to Retained Earnings from AOCI (Detail) - USD ($) $ in Thousands		4 Months Ended
	Dec. 31, 2017	Apr. 21, 2018	Apr. 22, 2017
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Pension and postretirement plans		$ 4,309	$ (1,612)
Retained Earnings
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Pension and postretirement plans	$ (17,097)
Hedged financial instruments	(1,709)
Total reclassification of stranded income tax effects to retained earnings from AOCI	(18,806)
AOCI
New Accounting Pronouncements Or Change In Accounting Principle [Line Items]
Pension and postretirement plans	17,097
Hedged financial instruments	1,709
Total reclassification of stranded income tax effects to retained earnings from AOCI	$ 18,806