Sales by Product Category in Each Reportable Segment (Detail) - USD ($) $ in Thousands	4 Months Ended
	Apr. 21, 2018	Apr. 22, 2017
Segment Reporting Information [Line Items]
Sales	$ 1,206,453	$ 1,187,649
DSD Segment
Segment Reporting Information [Line Items]
Sales	1,015,484	999,860
Warehouse Segment
Segment Reporting Information [Line Items]
Sales	190,969	187,789
Branded Retail
Segment Reporting Information [Line Items]
Sales	711,180	694,743
Branded Retail | DSD Segment
Segment Reporting Information [Line Items]
Sales	664,134	645,943
Branded Retail | Warehouse Segment
Segment Reporting Information [Line Items]
Sales	47,046	48,800
Store Branded Retail
Segment Reporting Information [Line Items]
Sales	172,576	172,224
Store Branded Retail | DSD Segment
Segment Reporting Information [Line Items]
Sales	136,684	137,533
Store Branded Retail | Warehouse Segment
Segment Reporting Information [Line Items]
Sales	35,892	34,691
Non-Retail and Other
Segment Reporting Information [Line Items]
Sales	322,697	320,682
Non-Retail and Other | DSD Segment
Segment Reporting Information [Line Items]
Sales	214,666	216,384
Non-Retail and Other | Warehouse Segment
Segment Reporting Information [Line Items]
Sales	$ 108,031	$ 104,298