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]
Provisions for (benefit from) income taxes	$ (2,756)	$ 2,047	$ 97	$ 8,025
Pretax net income on tax provisions	7,501	6,852	23,308	29,824
Provisions for income taxes before discrete items	$ 3,500	4,200	$ 7,600	13,200
U.S. statutory income tax rate	35.00%		35.00%
Tax benefit related to the increased valuation of intangible assets resulting from merger of subsidiaries				3,100
Previously unrecognized tax benefits from result of expiration of U.S. federal statute of limitations	$ 4,400	$ 2,300	$ 4,900	$ 2,400
Unrecognized tax benefits that would affect the effective tax rate if recognized	31,300		31,300		$ 32,100
Gross unrecognized tax benefits decrease in next 12 months	4,200		4,200
Offset to deferred tax assets for unrecognized tax benefits			20,500
Estimated unrecognized tax benefits	10,800		10,800
Accrued interest and penalties related to unrecognized tax benefits	$ 500		$ 500		$ 900