Condensed Consolidated Statements of Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Income Statement [Abstract]
Net sales	$ 93,870	$ 112,258	$ 186,521	$ 215,433
Cost of sales	65,384	78,328	126,106	149,917
Gross profit	28,486	33,930	60,415	65,516
Selling and administrative expenses	21,476	20,131	44,732	41,076
Acquisition and integration expenses		324		361
Amortization and earn-out (income) expenses, net	(2,245)	4,914	5,078	9,711
Income from operations	9,255	8,561	10,605	14,368
Other income (expense), net	360	(399)	251	381
Interest expense	(1,645)	(1,980)	(3,356)	(4,082)
Income before income taxes	7,970	6,182	7,500	10,667
Income tax expense	2,484	2,145	1,976	3,575
Net income	5,486	4,037	5,524	7,092
Net loss attributable to noncontrolling interest		(13)		(58)
Net income attributable to CECO Environmental Corp.	$ 5,486	$ 4,050	$ 5,524	$ 7,150
Earnings per share:
Basic	$ 0.16	$ 0.12	$ 0.16	$ 0.21
Diluted	$ 0.16	$ 0.12	$ 0.16	$ 0.21
Weighted average number of common shares outstanding:
Basic	34,473,688	33,946,117	34,345,317	33,937,128
Diluted	34,806,808	34,161,543	34,685,687	34,139,087