Unaudited Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 02, 2021	Sep. 26, 2020	Oct. 02, 2021	Sep. 26, 2020
Comprehensive income (loss)
Net income	$ 75,378	$ 92,769	$ 109,891	$ 104,930
Other comprehensive income (loss):
Foreign currency translation adjustment	(4,076)	2,018	682	(3,395)
Less tax effect of other comprehensive income (loss) items	823	(494)	(176)	831
Other comprehensive (loss) income	(3,253)	1,524	506	(2,564)
Comprehensive income	72,125	94,293	110,397	102,366
Less comprehensive income attributable to Summit Holdings	1,117	2,091	1,584	2,024
Comprehensive income attributable to Summit Inc./LLC	71,008	92,202	108,813	100,342
Summit Materials, LLC
Comprehensive income (loss)
Net income	88,875	78,324	130,900	84,716
Other comprehensive income (loss):
Foreign currency translation adjustment	(4,076)	2,018	682	(3,395)
Other comprehensive (loss) income	(4,076)	2,018
Comprehensive income attributable to Summit Inc./LLC	$ 84,799	$ 80,342	$ 131,582	$ 81,321