Acquisitions - Schedule of Unaudited Pro Forma Financial Information (Details) - General Rubber LLC [Member] - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Business Acquisition [Line Items]
Net sales	$ 136,533	$ 156,503	$ 406,507	$ 420,078
Net income attributable to CECO Environmental Corp.	$ 2,838	$ 4,257	$ 9,910	$ 11,881
Earnings per share:
Basic	$ 0.08	$ 0.12	$ 0.28	$ 0.34
Diluted	$ 0.08	$ 0.12	$ 0.27	$ 0.34