Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Net sales	$ 417,011	$ 367,422	$ 263,217
Cost of sales	282,152	258,251	178,394
Gross profit	134,859	109,171	84,823
Selling and administrative expenses	81,743	67,329	51,440
Acquisition and integration expenses	524	7,940	1,269
Amortization and earn out expenses	20,231	25,613	10,151
Intangible asset and goodwill impairment	57,923	3,340
Legal reserves			300
(Loss) income from operations	(25,562)	4,949	21,663
Other income (expense), net	310	(2,081)	(2,311)
Interest expense	(7,712)	(5,964)	(3,138)
(Loss) income before income taxes	(32,964)	(3,096)	16,214
Income tax expense	5,290	2,638	3,137
Net (loss) income	(38,254)	(5,734)	13,077
Less net loss attributable to noncontrolling interest	(36)	(132)
Net (loss) income attributable to CECO Environmental Corp.	$ (38,218)	$ (5,602)	$ 13,077
(Loss) earnings per share:
Basic	$ (1.12)	$ (0.19)	$ 0.51
Diluted	$ (1.12)	$ (0.19)	$ 0.50
Weighted average number of common shares outstanding:
Basic	33,979,549	28,791,662	25,750,972
Diluted	33,979,549	28,791,662	26,196,901