Information Regarding Operations in Reportable Segments (Detail) - USD ($) $ in Thousands			3 Months Ended			4 Months Ended		6 Months Ended	9 Months Ended
		Jan. 14, 2017	Oct. 06, 2018	Jul. 14, 2018	Oct. 07, 2017	Apr. 21, 2018	Apr. 22, 2017	Jul. 14, 2018	Oct. 06, 2018	Oct. 07, 2017
Segment Reporting Information [Line Items]
Sales			$ 923,449		$ 932,822				$ 3,071,185	$ 3,047,110
Gain on divestiture		$ 28,875					$ 28,900			28,875
Multi-employer pension plan withdrawal costs					18,268				2,322	18,268
Loss (recovery) on inferior ingredients			(1,891)					$ 3,884	1,993
Restructuring charges			497		100,549				2,557	100,549
Impairment of assets						$ 2,500			2,483
Depreciation and amortization			32,662		32,972				111,949	114,288
Income from operations			53,450		(52,057)				182,329	114,868
Interest expense			(8,180)		(8,194)				(27,390)	(28,255)
Interest income			6,615		5,464				21,176	17,199
Pension plan settlement loss			(930)	$ (1,035)	(3,030)	$ (4,668)			(6,633)	(3,030)
Other components of net periodic pension and postretirement benefits credit			171		1,321				1,204	4,687
Income before income taxes			51,126		(56,496)				170,686	105,469
Operating Segments
Segment Reporting Information [Line Items]
Gain on divestiture										28,875
Unallocated Corporate Costs
Segment Reporting Information [Line Items]
Restructuring charges			33		3,833				119	3,833
Depreciation and amortization	[1]		70		(83)				233	(256)
Income from operations	[2]		(11,235)		(22,637)				(46,959)	(78,722)
DSD Segment
Segment Reporting Information [Line Items]
Sales			780,253		787,255				2,592,363	2,580,007
Loss (recovery) on inferior ingredients								$ 3,884	898
DSD Segment | Operating Segments
Segment Reporting Information [Line Items]
Sales			799,271		803,153				2,659,639	2,628,365
Multi-employer pension plan withdrawal costs					18,268				2,322	18,268
Loss (recovery) on inferior ingredients			(2,986)						898
Restructuring charges			289		76,625				2,187	76,625
Impairment of assets									2,483
Depreciation and amortization			27,676		28,286				95,273	98,703
Income from operations			58,819		(20,338)				197,725	146,388
DSD Segment | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales			(19,018)		(15,898)				(67,276)	(48,358)
Warehouse Segment
Segment Reporting Information [Line Items]
Sales			143,196		145,567				478,822	467,103
Loss (recovery) on inferior ingredients			1,095						1,095
Warehouse Segment | Operating Segments
Segment Reporting Information [Line Items]
Sales			182,639		185,219				615,530	596,740
Restructuring charges			175		20,091				251	20,091
Depreciation and amortization			4,916		4,769				16,443	15,841
Income from operations			5,866		(9,082)				31,563	47,202
Warehouse Segment | Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales			$ (39,443)		$ (39,652)				$ (136,708)	$ (129,637)

[1] Represents costs allocated to the company’s corporate head office.

[2] Represents costs allocated to the company’s corporate head office and pension plan settlement loss.