Acquisitions - (PMFG) - Additional Information (Detail) - PMFG, Inc. [Member] $ / shares in Units, $ in Millions		12 Months Ended
	Sep. 03, 2015 USD ($) $ / shares shares	Dec. 31, 2015 USD ($) $ / shares
Business Acquisition [Line Items]
Purchase price of acquisition	$ 136.7
Stock consideration per share | $ / shares	$ 6.85
Trading day period	15 days
Percentage of common stock converted into cash	44.50%
Cash consideration per share | $ / shares	$ 6.85	$ 9.49
Value of shares transferred for cash	$ 64.6
Trading price | $ / shares	$ 9.6655
Exchange ratio	0.6456
Shares of common stock in aggregate stock consideration | shares	7,602,166
Percentage of cash consideration		58.05%
Percentage of stock consideration		41.95%
Value of stock recorded for purchase accounting		$ 72.1
Revenue from acquired entity		40.8
Income from acquired entity		$ 2.2
Maximum [Member]
Business Acquisition [Line Items]
Common stock shares exchange ratio per share	0.6456
Minimum [Member]
Business Acquisition [Line Items]
Common stock shares exchange ratio per share	0.5282