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	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income tax expense	$ 3,066	$ 4,763	$ 5,808	$ 9,251
Income tax effective rate	134.60%	99.40%	427.00%	87.30%
Income tax effective rate excluding the impact of discrete charges	63.30%	74.70%	279.20%	68.40%
Gross unrecognized tax benefit	$ 15,500		$ 15,500		$ 15,600
Accrued interest and penalties related to unrecognized tax benefits	$ 500		$ 500		$ 500