Consolidated Statements of Comprehensive Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Oct. 01, 2016	Sep. 30, 2017	Oct. 01, 2016
Net (loss) income	$ 82,075	$ 61,106	$ 79,055	$ 40,077
Other comprehensive income (loss):
Postretirement liability adjustment			413
Foreign currency translation adjustment	4,374	(1,311)	8,498	3,966
Income (loss) on cash flow hedges	212	60	384	(3,232)
Other comprehensive income (loss)	4,586	(1,251)	9,295	734
Comprehensive income	86,661	59,855	88,350	40,811
Less comprehensive income (loss) attributable to the noncontrolling interest in consolidated subsidiaries	59	92	(27)	57
Less comprehensive income (loss) attributable Summit Holdings	3,135	15,827	2,832	3,751
Comprehensive income attributable to Summit Materials, Inc. / Summit Materials, LLC	83,467	43,936	85,545	37,003
Summit Materials, LLC
Net (loss) income	82,633	61,360	81,606	40,876
Other comprehensive income (loss):
Postretirement liability adjustment			413
Foreign currency translation adjustment	4,374	(1,311)	8,498	3,966
Income (loss) on cash flow hedges	212	60	384	(3,232)
Other comprehensive income (loss)	4,586	(1,251)	9,295	734
Comprehensive income	87,219	60,109	90,901	41,610
Less comprehensive income (loss) attributable to noncontrolling interest	59	92	(27)	57
Comprehensive income attributable to Summit Materials, Inc. / Summit Materials, LLC	$ 87,160	$ 60,017	$ 90,928	$ 41,553