Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Income Tax [Line Items]
Income tax expense	$ 1,295	$ 2,009	$ 5,321	$ 4,981
Effective income tax rate			34.80%	40.70%
Loss on liquidation of foreign subsidiary			$ 300
Income tax benefit from new interpretation of tax law	$ 700
U.S. State [Member]
Income Tax [Line Items]
Audit expense					$ 200