Line of Credit (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Aug. 10, 2012
Line of Credit Facility [Line Items]
Write off of Deferred Debt Issuance Cost	$ 200,000
Other non-current assets [Member]
Line of Credit Facility [Line Items]
Deferred financing costs				$ 200,000
Other Current Assets [Member]
Line of Credit Facility [Line Items]
Deferred financing costs			$ 300,000
Senior Credit Facility [Member]
Line of Credit Facility [Line Items]
Senior Credit Facility					$ 140,000,000.0
Deferred financing costs			$ 1,000,000
Senior Credit Facility, maturity date		Aug. 10, 2017