Income Taxes - Components of Net Deferred Income Tax Assets and Liabilities (Detail) - USD ($) $ in Thousands	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Deferred tax assets (liabilities):
Net intangible assets	$ 275,412	$ 316,950
Accelerated depreciation	(185,020)	(147,943)
Net operating loss	143,234	94,751
Investment in limited partnership	(29,981)	(14,467)
Mining reclamation reserve	1,600	1,239
Inventory purchase accounting adjustments	0	0
Working capital (e.g., accrued compensation, prepaid assets)	(36,932)	(35,237)
Interest expense limitation carryforward	2,586	0
Less valuation allowance	(19,366)	(1,675)	$ (502,839)
Deferred tax assets	225,397	284,092
Less foreign deferred tax liability (included in other noncurrent liabilities)	(5,133)	(3,992)
Net deferred tax asset	220,264	280,100
Summit Materials, LLC
Deferred tax assets (liabilities):
Net intangible assets	(1,734)	(1,256)
Accelerated depreciation	(57,437)	(47,920)
Net operating loss	22,915	20,671
Investment in limited partnership	(16,591)	(10,800)
Mining reclamation reserve	570	488
Working capital (e.g., accrued compensation, prepaid assets)	(1,059)	(1,267)
Interest expense limitation carryforward	2,586	0
Less valuation allowance	(4,261)	(1,675)
Deferred tax liabilities, net	(48,632)	(37,550)
Net deferred tax liability, net	$ (52,893)	$ (39,225)