Unaudited Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 28, 2019	Sep. 29, 2018
Comprehensive income (loss)
Net income	$ 58,237	$ 73,992	$ 24,726	$ 54,957
Other comprehensive income (loss):
Foreign currency translation adjustment	(1,328)	1,970	3,263	(3,179)
Income (loss) on cash flow hedges	155	87	(148)	1,443
Less tax effect of other comprehensive income (loss) items	284	(507)	(766)	428
Other comprehensive (loss) income	(889)	1,550	2,349	(1,308)
Comprehensive income	57,348	75,542	27,075	53,649
Less comprehensive income attributable to Summit Holdings	2,444	2,764	1,423	1,832
Comprehensive income attributable to Summit Inc.	54,904	72,778	25,652	51,817
Summit Materials, LLC
Comprehensive income (loss)
Net income	85,199	90,427	47,136	68,433
Other comprehensive income (loss):
Foreign currency translation adjustment	(1,328)	1,970	3,263	(3,179)
Income (loss) on cash flow hedges	155	87	(148)	1,443
Other comprehensive (loss) income	(1,173)	2,057	3,115	(1,736)
Comprehensive income attributable to Summit Inc.	$ 84,026	$ 92,484	$ 50,251	$ 66,697