Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 29, 2018	Dec. 30, 2017	Dec. 31, 2016
Cash flow from operating activities:
Net income	$ 36,330	$ 125,777	$ 46,126
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion, amortization and accretion	208,772	193,107	160,633
Share-based compensation expense	25,378	21,140	49,940
Net gain on asset disposals	(30,093)	(7,638)	(3,102)
Non-cash loss on debt financings	0	3,856	0
Change in deferred tax asset, net	57,490	(289,219)	(4,263)
Other	2,018	(2,359)	(1,282)
(Increase) decrease in operating assets, net of acquisitions and dispositions:
Accounts receivable, net	(5,796)	(3,720)	2,511
Inventories	(11,598)	(18,609)	(10,297)
Costs and estimated earnings in excess of billings	(8,702)	(1,825)	(2,684)
Other current assets	(7,159)	8,703	(5,518)
Other assets	(106)	(3,103)	(2,350)
(Decrease) increase in operating liabilities, net of acquisitions and dispositions:
Accounts payable	(13,403)	6,192	(5,751)
Accrued expenses	(16,544)	(7,006)	13,196
Billings in excess of costs and estimated earnings	(5,052)	109	700
Tax receivable agreement liability	(21,666)	273,194	58,145
Other liabilities	(501)	(6,416)	(51,141)
Net cash provided by operating activities	209,368	292,183	244,863
Cash flow from investing activities:
Acquisitions, net of cash acquired	(246,017)	(374,930)	(336,958)
Purchases of property, plant and equipment	(220,685)	(194,146)	(153,483)
Proceeds from the sale of property, plant and equipment	21,635	17,072	16,868
Proceeds from sale of business	21,564	0	0
Other	3,804	(471)	2,921
Net cash used for investing activities	(419,699)	(552,475)	(470,652)
Cash flow from financing activities:
Proceeds from equity offerings	0	237,600	0
Capital issuance costs	0	(627)	(136)
Proceeds from debt issuances	64,500	302,000	354,000
Debt issuance costs	(550)	(6,416)	(5,801)
Payments on debt	(85,042)	(16,438)	(120,702)
Purchase of noncontrolling interests	0	(532)	0
Payments on acquisition-related liabilities	(36,504)	(34,650)	(32,040)
Distributions from partnership	(69)	(1,974)	(13,034)
Proceeds from stock option exercises	15,615	21,661	440
Other	(1,943)	(869)	(20)
Net cash (used in) provided by financing activities	(43,993)	499,755	182,707
Impact of foreign currency on cash	(724)	701	69
Net (decrease) increase in cash	(255,048)	240,164	(43,013)
Cash and cash equivalents—beginning of period	383,556	143,392	186,405
Cash and cash equivalents—end of period	128,508	383,556	143,392
Summit Materials, LLC
Cash flow from operating activities:
Net income	63,837	134,041	62,087
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion, amortization and accretion	208,055	192,213	159,579
Share-based compensation expense	25,378	21,140	49,940
Net gain on asset disposals	(30,093)	(7,638)	(3,102)
Non-cash loss on debt financings	0	3,856	0
Change in deferred tax asset, net	9,729	(23,070)	(8,572)
Other	2,018	(2,359)	(1,282)
(Increase) decrease in operating assets, net of acquisitions and dispositions:
Accounts receivable, net	(5,796)	(3,720)	2,511
Inventories	(11,598)	(18,609)	(10,297)
Costs and estimated earnings in excess of billings	(8,702)	(1,825)	(2,684)
Other current assets	(7,159)	8,703	(5,518)
Other assets	(106)	(3,103)	1,976
(Decrease) increase in operating liabilities, net of acquisitions and dispositions:
Accounts payable	(13,989)	8,040	(5,706)
Accrued expenses	(16,653)	(6,230)	12,064
Billings in excess of costs and estimated earnings	(5,052)	109	700
Other liabilities	(501)	(6,416)	(6,819)
Net cash provided by operating activities	209,368	295,132	244,877
Cash flow from investing activities:
Acquisitions, net of cash acquired	(246,017)	(374,930)	(336,958)
Purchases of property, plant and equipment	(220,685)	(194,146)	(153,483)
Proceeds from the sale of property, plant and equipment	21,635	17,072	16,868
Proceeds from sale of business	21,564	0	0
Other	3,804	(471)	2,921
Net cash used for investing activities	(419,699)	(552,475)	(470,652)
Cash flow from financing activities:
Capital contributions by member	15,615	304,541	27,377
Capital issuance costs	0	(627)	(136)
Proceeds from debt issuances	64,500	302,000	354,000
Debt issuance costs	(550)	(6,416)	(5,801)
Payments on debt	(85,042)	(16,438)	(120,702)
Purchase of noncontrolling interests	0	(532)	0
Payments on acquisition-related liabilities	(34,004)	(32,150)	(29,540)
Distributions from partnership	(2,569)	(51,986)	(42,192)
Other	(1,943)	(866)	(16)
Net cash (used in) provided by financing activities	(43,993)	497,526	182,990
Impact of foreign currency on cash	(724)	701	69
Net (decrease) increase in cash	(255,048)	240,884	(42,716)
Cash and cash equivalents—beginning of period	383,556	142,672	185,388
Cash and cash equivalents—end of period	$ 128,508	$ 383,556	$ 142,672