Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016
Cash flow from operating activities:
Net (loss) income	$ 79,055	$ 40,077
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation, depletion, amortization and accretion	140,634	118,026
Share-based compensation expense	14,148	46,123
Deferred income tax benefit (expense)	4,768	(8,994)
Net gain on asset disposals	(6,063)	(5,844)
Non-cash loss on debt financings	85
Other	(855)	(971)
(Increase) decrease in operating assets, net of acquisitions:
Accounts receivable, net	(98,961)	(81,234)
Inventories	(12,835)	(17,072)
Costs and estimated earnings in excess of billings	(31,606)	(34,349)
Other current assets	6,043	(2,876)
Deferred tax assets, net	(488,852)
Other assets	(3,141)	(217)
Increase (decrease) in operating liabilities, net of acquisitions:
Accounts payable	38,357	23,812
Accrued expenses	3,854	8,948
Billings in excess of costs and estimated earnings	2,386	2,138
Tax receivable agreement liability	490,740
Other liabilities	(5,324)	(3,044)
Net cash used in operating activities	132,433	84,523
Cash flow from investing activities:
Acquisitions, net of cash acquired	(371,479)	(331,463)
Purchases of property, plant and equipment	(147,478)	(121,945)
Proceeds from the sale of property, plant and equipment	13,290	16,222
Other	182	1,500
Net cash used for investing activities	(505,485)	(435,686)
Cash flow from financing activities:
Proceeds from equity offerings	237,600
Capital issuance costs	(627)	(136)
Proceeds from debt issuances	302,000	354,000
Debt issuance costs	(5,317)	(5,675)
Payments on debt	(12,887)	(114,254)
Payments on acquisition-related liabilities	(22,616)	(28,920)
Distributions	(109)	(9,049)
Other	17,964	105
Net cash provided by financing activities	516,008	196,071
Impact of cash on foreign currency	734	330
Net increase (decrease) in cash	143,690	(154,762)
Cash and cash equivalents-beginning of period	143,392	186,405
Cash and cash equivalents-end of period	287,082	31,643
Summit Materials, LLC
Cash flow from operating activities:
Net (loss) income	81,606	40,876
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation, depletion, amortization and accretion	139,953	117,227
Share-based compensation expense	14,148	46,123
Deferred income tax benefit (expense)	4,768	(8,977)
Net gain on asset disposals	(6,063)	(5,844)
Non-cash loss on debt financings	85
Other	(855)	(971)
(Increase) decrease in operating assets, net of acquisitions:
Accounts receivable, net	(98,961)	(81,234)
Inventories	(12,835)	(17,072)
Costs and estimated earnings in excess of billings	(31,606)	(34,349)
Other current assets	6,043	(2,876)
Other assets	(3,141)	(217)
Increase (decrease) in operating liabilities, net of acquisitions:
Accounts payable	37,705	23,812
Accrued expenses	4,986	8,931
Billings in excess of costs and estimated earnings	2,386	2,138
Other liabilities	(5,324)	(3,044)
Net cash used in operating activities	132,895	84,523
Cash flow from investing activities:
Acquisitions, net of cash acquired	(371,479)	(331,463)
Purchases of property, plant and equipment	(147,478)	(121,945)
Proceeds from the sale of property, plant and equipment	13,290	16,222
Other	182	1,500
Net cash used for investing activities	(505,485)	(435,686)
Cash flow from financing activities:
Capital contributions by member	256,667	113
Capital issuance costs	(627)	(136)
Proceeds from debt issuances	302,000	354,000
Debt issuance costs	(5,317)	(5,675)
Payments on debt	(12,887)	(114,254)
Payments on acquisition-related liabilities	(20,116)	(26,420)
Distributions	(2,609)	(27,993)
Other	(845)	(8)
Net cash provided by financing activities	516,266	179,627
Impact of cash on foreign currency	734	330
Net increase (decrease) in cash	144,410	(171,206)
Cash and cash equivalents-beginning of period	142,672	185,388
Cash and cash equivalents-end of period	$ 287,082	$ 14,182