Unaudited Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2020	Mar. 30, 2019
Revenue:
Revenue	$ 367,190	$ 332,639
Cost of revenue (excluding items shown separately below):
Net cost of revenue	286,155	267,004
General and administrative expenses	70,224	67,610
Depreciation, depletion, amortization and accretion	51,778	55,388
Transaction costs	753	308
Operating loss	(41,720)	(57,671)
Interest expense	27,818	30,105
Loss on debt financings	0	14,565
Other loss (income), net	89	(2,803)
Loss from operations before taxes	(69,627)	(99,538)
Income tax benefit	(22,901)	(28,037)
Net loss	(46,726)	(71,501)
Net loss attributable to Summit Holdings	(1,747)	(2,729)
Net loss attributable to Summit Inc.	(44,979)	(68,772)
Summit Materials, LLC
Revenue:
Revenue	367,190	332,639
Cost of revenue (excluding items shown separately below):
Net cost of revenue	286,155	267,004
General and administrative expenses	70,224	67,610
Depreciation, depletion, amortization and accretion	51,778	55,388
Transaction costs	753	308
Operating loss	(41,720)	(57,671)
Interest expense	27,700	29,937
Loss on debt financings	0	14,565
Other loss (income), net	89	(2,803)
Loss from operations before taxes	(69,509)	(99,370)
Income tax benefit	(5,884)	(7,806)
Net loss	(63,625)	(91,564)
Net loss attributable to Summit Inc.	$ (63,625)	$ (91,564)
Class A Common Stock
Loss per share of Class A common stock:
Basic (usd per share)	$ (0.40)	$ (0.62)
Diluted (usd per share)	$ (0.40)	$ (0.62)
Weighted average shares of Class A common stock:
Basic (in shares)	113,602,110	111,811,679
Diluted (in shares)	113,602,110	111,811,679
Product
Revenue:
Revenue	$ 305,307	$ 271,641
Cost of revenue (excluding items shown separately below):
Net cost of revenue	232,504	213,726
Product | Summit Materials, LLC
Revenue:
Revenue	305,307	271,641
Cost of revenue (excluding items shown separately below):
Net cost of revenue	232,504	213,726
Service
Revenue:
Revenue	37,099	34,309
Cost of revenue (excluding items shown separately below):
Net cost of revenue	28,867	26,589
Service | Summit Materials, LLC
Revenue:
Revenue	37,099	34,309
Cost of revenue (excluding items shown separately below):
Net cost of revenue	28,867	26,589
Excluding delivery and subcontract revenue
Revenue:
Revenue	342,406	305,950
Cost of revenue (excluding items shown separately below):
Net cost of revenue	261,371	240,315
Excluding delivery and subcontract revenue | Summit Materials, LLC
Revenue:
Revenue	342,406	305,950
Cost of revenue (excluding items shown separately below):
Net cost of revenue	261,371	240,315
Delivery and subcontract revenue
Revenue:
Revenue	24,784	26,689
Cost of revenue (excluding items shown separately below):
Net cost of revenue	24,784	26,689
Delivery and subcontract revenue | Summit Materials, LLC
Revenue:
Revenue	24,784	26,689
Cost of revenue (excluding items shown separately below):
Net cost of revenue	$ 24,784	$ 26,689