Acquisitions - Fair Values of Assets Acquired and Liabilities Assumed at Date of Closing - Met-Pro Corporation (Parenthetical) (Detail) - Met-Pro [Member] $ in Millions	12 Months Ended
Dec. 31, 2015 USD ($) Property	Dec. 31, 2014 USD ($) Property
Business Acquisition [Line Items]
Number of properties sold \| Property	3	3
Proceeds from properties sold	$ 3.2	$ 6.7
Remaining assets held for sale	$ 0.7

The cash inflow from the sale of formerly productive land held for sale, anything permanently fixed to it, including buildings, structures on it, and so forth.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3179-108585

Name:	us-gaap_ProceedsFromSaleOfPropertyHeldForSale
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration