Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Income Tax Disclosure [Abstract]
Income tax expense	$ 1,233	$ 419	$ 2,249	$ 1,059
Valuation allowance	$ 41,300		$ 41,300