Unaudited Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Apr. 02, 2022	Apr. 03, 2021
Revenue:
Revenue	$ 420,947	$ 427,844
Cost of revenue (excluding items shown separately below):
Net cost of revenue	353,380	346,694
General and administrative expenses	51,924	51,642
Depreciation, depletion, amortization and accretion	51,193	56,336
Gain on sale of property, plant and equipment	(1,255)	(1,769)
Operating (loss) income	(34,295)	(25,059)
Interest expense	20,149	24,186
Gain on sale of businesses	(14,205)	(15,668)
Other income, net	(696)	(4,889)
Loss from operations before taxes	(39,543)	(28,688)
Income tax benefit	(4,743)	(5,443)
Net loss	(34,800)	(23,245)
Net loss attributable to Summit Holdings	(508)	(728)
Net income (loss) attributable to Summit Inc/LLC	(34,292)	(22,517)
Summit Materials, LLC
Revenue:
Revenue	420,947	427,844
Cost of revenue (excluding items shown separately below):
Net cost of revenue	353,380	346,694
General and administrative expenses	51,924	51,642
Depreciation, depletion, amortization and accretion	51,193	56,336
Gain on sale of property, plant and equipment	(1,255)	(1,769)
Operating (loss) income	(34,295)	(25,059)
Interest expense	20,149	24,124
Gain on sale of businesses	(14,205)	(15,668)
Other income, net	(696)	(4,889)
Loss from operations before taxes	(39,543)	(28,626)
Income tax benefit	6,844	(836)
Net loss	(46,387)	(27,790)
Net income (loss) attributable to Summit Inc/LLC	$ (46,387)	$ (27,790)
Common Class A
Loss per share of Class A common stock:
Basic (usd per share)	$ (0.29)	$ (0.19)
Diluted (usd per share)	$ (0.29)	$ (0.20)
Weighted average shares of Class A common stock:
Basic (in shares)	118,777,341	115,411,204
Diluted (in shares)	118,937,466	115,411,204
Common Class A And Restricted Stock
Loss per share of Class A common stock:
Basic (usd per share)	$ (0.29)	$ (0.19)
Weighted average shares of Class A common stock:
Basic (in shares)	118,937,466	115,664,725
Excluding delivery and subcontract revenue
Revenue:
Revenue	$ 392,495	$ 398,481
Cost of revenue (excluding items shown separately below):
Net cost of revenue	324,928	317,331
Excluding delivery and subcontract revenue | Summit Materials, LLC
Revenue:
Revenue	392,495	398,481
Cost of revenue (excluding items shown separately below):
Net cost of revenue	324,928	317,331
Product
Revenue:
Revenue	355,669	354,234
Cost of revenue (excluding items shown separately below):
Net cost of revenue	290,345	277,134
Product | Summit Materials, LLC
Revenue:
Revenue	355,669	354,234
Cost of revenue (excluding items shown separately below):
Net cost of revenue	290,345	277,134
Service
Revenue:
Revenue	36,826	44,247
Cost of revenue (excluding items shown separately below):
Net cost of revenue	34,583	40,197
Service | Summit Materials, LLC
Revenue:
Revenue	36,826	44,247
Cost of revenue (excluding items shown separately below):
Net cost of revenue	34,583	40,197
Delivery and subcontract revenue
Revenue:
Revenue	28,452	29,363
Cost of revenue (excluding items shown separately below):
Net cost of revenue	28,452	29,363
Delivery and subcontract revenue | Summit Materials, LLC
Revenue:
Revenue	28,452	29,363
Cost of revenue (excluding items shown separately below):
Net cost of revenue	$ 28,452	$ 29,363