Acquisition - Additional Information (Detail) (USD $)	0 Months Ended	3 Months Ended				6 Months Ended
	Feb. 20, 2014	Jun. 30, 2014		Jun. 30, 2013		Jun. 30, 2014		Jun. 30, 2013		Feb. 20, 2014
Business Acquisition [Line Items]
Cash Acquired										$ 7,493,000
Business Combination Purchase Price Borrowings										60,000,000
Line of credit facility, maximum borrowing capacity		100,000,000				100,000,000				100,000,000
Net sales		148,793,000		101,051,000		274,019,000		200,080,000
Operating Income (Loss)		12,573,000	[1]	9,521,000	[1]	20,199,000	[1]	16,038,000	[1]
Cost of Goods Sold, Direct Materials	2,100,000
Acquisition-related Costs [Member]
Business Acquisition [Line Items]
Revenues		200,000		200,000		2,600,000		2,600,000
Amortization of Acquired Intangible Assets [Member]
Business Acquisition [Line Items]
Revenues				100,000
Interest Expense Associated with Borrowings Under the Company's Amended Credit Facility [Member]
Business Acquisition [Line Items]
Revenues				200,000				400,000
Fair Value Adjustment to Inventory [Member]
Business Acquisition [Line Items]
Revenues		500,000				1,800,000		2,300,000
Industrial Filtration [Member]
Business Acquisition [Line Items]
Net sales		34,100,000				51,800,000
Operating Income (Loss)		2,198,000	[1]	0	[1]	2,984,000	[1]	0	[1]
Cost of Goods Sold, Direct Materials		500,000				1,800,000
Andrew Industries Limited [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	86,700,000
Andrew Industries Limited [Member]
Business Acquisition [Line Items]
Business Combination, Acquisition Related Costs		$ 200,000				$ 2,600,000

[1] Industrial Filtration segment reports results for the period following the date of acquisition of February 20, 2014 through June 30, 2014.