Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Income tax provision	$ 1,486	$ 1,294	$ 30,742	$ 4,632
Liability for income taxes associated with uncertain tax positions	9,295		9,295
Net amount of unrecognized tax benefit related to uncertain tax positions that would impact, if recognized, effective income tax rate	1,624		1,624
Unrecognized tax benefit liabilities decrease	426		426
Increase in gross liability for uncertain tax positions	550		1,039
Provision expense (benefit) for income taxes related to interest and penalties	132	$ 54	241	$ 83
Income tax accrued for payment of interest and penalties	$ 1,558		$ 1,558		$ 1,317