Annual report pursuant to Section 13 and 15(d)

Income Taxes - Additional Information (Detail)

v3.6.0.2
Income Taxes - Additional Information (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Valuation Allowance [Line Items]      
Deferred tax assets, valuation allowance $ 288,408 $ 662,909  
Liabilities for unrecognized tax benefits 0 0 $ 0
Interest and penalty charges 0 0 $ 0
Federal      
Valuation Allowance [Line Items]      
Operating loss carryforwards $ 120,300    
Federal | Minimum      
Valuation Allowance [Line Items]      
Operating loss carryforward expiration year 2032    
Federal | Maximum      
Valuation Allowance [Line Items]      
Operating loss carryforward expiration year 2036    
State and Local Jurisdiction      
Valuation Allowance [Line Items]      
Operating loss carryforwards $ 69,600    
Operating loss carryforwards, valuation allowance $ 288,400    
State and Local Jurisdiction | Minimum      
Valuation Allowance [Line Items]      
Operating loss carryforward expiration year 2024    
State and Local Jurisdiction | Maximum      
Valuation Allowance [Line Items]      
Operating loss carryforward expiration year 2036    
Federal, State and Local Tax Jurisdictions      
Valuation Allowance [Line Items]      
Deferred tax assets, valuation allowance   $ 662,900  
Federal and state valuation allowance established against net deferred tax assets $ 374,500