Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement Of Income And Comprehensive Income [Abstract]
Net (loss) income	$ (38,254)	$ (5,734)	$ 13,077
Other comprehensive (loss) income, net of tax:
Translation loss	(3,864)	(2,664)	(1,597)
Interest rate swap	312
Minimum pension/postretirement liability adjustment	87	(292)	(4,052)
Comprehensive (loss) income	(41,719)	(8,690)	7,428
Net loss attributable to noncontrolling interest	(36)	(132)
Comprehensive (loss) income attributable to CECO Environmental Corp.	$ (41,683)	$ (8,558)	$ 7,428