Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Valuation allowance for deferred tax assets	$ 164,616		$ 164,616
Income tax provision	1,937	$ 1,817	3,338	$ 3,455
Liability for income taxes associated with uncertain tax positions	7,322		7,322
Net amount of unrecognized tax benefit related to uncertain tax positions that would impact, if recognized, effective income tax rate	903		903
Unrecognized tax benefit liabilities decrease	184		184
Increase in gross liability for uncertain tax positions	261		232
Provision expense (benefit) for income taxes related to interest and penalties	54	$ (10)	29	$ (35)
Income tax accrued for payment of interest and penalties	$ 1,089		$ 1,089		$ 1,060