Acquisitions - Fair Values of Assets and Liabilities Assumed at Date of Closing - PMFG (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Sep. 03, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Goodwill	$ 221,717	$ 220,163		$ 165,861
PMFG, Inc. [Member]
Business Acquisition [Line Items]
Current assets (including cash of $27,100)			$ 93,024
Property and equipment			29,982
Other assets			953
Assets held for sale			950
Goodwill			56,785
Intangible – finite life			29,940
Intangible – indefinite life			10,280
Total assets acquired			221,914
Current liabilities assumed			(73,328)
Deferred income tax liability			(1,899)
Long term liabilities assumed			(3,961)
Noncontrolling interest			(6,000)
Net assets acquired			$ 136,726