Income Taxes - Additional Information (Detail) - USD ($)
$ in Thousands
 3 Months Ended 9 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Dec. 31, 2015
Income Tax Disclosure [Abstract]          
Valuation allowance for deferred tax assets $ 164,616   $ 164,616    
Income tax provision 1,294 $ 1,547 4,632 $ 5,002  
Liability for income taxes associated with uncertain tax positions 7,660   7,660    
Net amount of unrecognized tax benefit related to uncertain tax positions that would impact, if recognized, effective income tax rate 920   920    
Unrecognized tax benefit liabilities decrease 181   181    
Increase in gross liability for uncertain tax positions 338   570    
Provision expense (benefit) for income taxes related to interest and penalties 54 $ 35 83 $ 1  
Income tax accrued for payment of interest and penalties $ 1,143   $ 1,143   $ 1,060