Income Taxes - Temporary Differences and Carryforwards that Comprised Deferred Income Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 30, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Acquisition related contingent consideration	$ 94,323	$ 94,055
Deferred compensation	26,154	27,097
Deferred revenue	25,027	18,704
Accrued liabilities	18,485	15,523
Postretirement benefits	13,843	16,443
Net operating loss carryforwards	7,628	1,923
Charitable contribution carryover	5,723	3,770
Pension (nonunion)	5,307	8,303
Transactional costs	5,291	5,733
Capital lease agreements	2,871	3,377
Pension (union)	1,724	1,922
Other	4,198	1,669
Deferred income tax assets	210,574	198,519
Less: Valuation allowance for deferred tax assets	5,899	4,337
Net deferred income tax asset	204,675	194,182
Intangible assets	(154,974)	(154,425)
Depreciation	(131,856)	(105,685)
Investment in Piedmont	(24,540)	(25,895)
Inventory	(10,553)	(9,781)
Prepaid expenses	(8,680)	(8,399)
Patronage dividend	(1,246)	(2,361)
Deferred income tax liabilities	(331,849)	(306,546)
Net deferred income tax liability	$ (127,174)	$ (112,364)