Acquisitions - Schedule of Unaudited Pro Forma Financial Information (Details) - Environmental Integrated Solutions [Member] - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
Mar. 31, 2025	Mar. 31, 2024
Business Acquisition [Line Items]
Net sales	$ 176,697	$ 163,957
Net income attributable to CECO Environmental Corp.	$ 35,984	$ 310
Earnings per share:
Basic	$ 1.03	$ 0.01
Diluted	$ 0.98	$ 0.01

The amount of net income (loss) from continuing operations per each share of common stock or unit outstanding during the reporting period.

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- Definition

The amount of net income (loss) derived from continuing operations during the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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