ENTRY INTO MERGER AGREEMENT (Details) (CECO Environmental Corp [Member], USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended
	Apr. 30, 2013
Business Acquisition [Line Items]
Share price (in dollars per share)	$ 13.75
Period considered for volume weighted average trading price	15 days
Exchange ratio for volume weighted average price 10.17 (in shares)	1.3520
Exchange ratio for volume weighted average price 13.75 (in shares)	1.0000
Percentage of common stock to be exchanged for cash (in hundredths)	53.00%
Capped amount for common stock exchanged for cash	$ 110.2
Percentage of common stock to be exchanged for shares (in hundredths)	47.00%
Termination fees to be paid under agreement	6.7
Reverse termination fee to be received under agreement	$ 10.4
Percentage of voting stock entered into voting agreement (in hundredths)	26.00%
Minimum [Member]
Business Acquisition [Line Items]
Volume weighted average trading price for exchange ratio of 1.0000 shares (in dollars per share)	$ 13.75
Maximum [Member]
Business Acquisition [Line Items]
Volume weighted average trading price for exchange ratio of 1.3520 shares (in dollars per share)	$ 10.17