Business Segment Information - Additional Information (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2015 Segment	Mar. 12, 2016 USD ($)
Segment Reporting [Abstract]
Number of reportable segments | Segment	2
ES | Disposal Group Sold | Pittsburgh, Pennsylvania Operations | Subsequent Event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Preliminary sales price		$ 38.5
ES | Disposal Group Sold | Miltec Operations | Subsequent Event
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Preliminary sales price		$ 14.6