Acquisition and Divestiture - Acquisitions (Detail) - USD ($)		3 Months Ended	9 Months Ended
	Feb. 20, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2015	May. 05, 2015	May. 04, 2015
Business Acquisition [Line Items]
Cash acquired	$ 7,493,000
Borrowings for acquisition of business, amended credit facility	60,000,000
Line of credit facility, maximum borrowing capacity	100,000,000			$ 100,000,000	$ 100,000,000	$ 35,000,000
Acquisition-related Costs [Member]
Business Acquisition [Line Items]
Revenues			$ 2,600,000
Amortization of Acquired Intangible Assets [Member]
Business Acquisition [Line Items]
Revenues		$ 200,000	$ 2,100,000
Andrew Industries Limited [Member]
Business Acquisition [Line Items]
Payments to acquire business	86,900,000
Cash acquired	7,500,000
Post closing adjustment payment	$ 200,000