Annual report pursuant to Section 13 and 15(d)

Income Taxes - Narrative (Details)

v3.7.0.1
Income Taxes - Narrative (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Tax Credit Carryforward [Line Items]      
Effective income tax rate reconciliation, at federal statutory income tax rate, percent 35.00%    
Valuation allowance, deferred tax asset, increase (decrease), amount $ 30,574    
Change in valuation allowance affecting tax expense 26,892 $ 24,149 $ 9,322
Increase (decrease) in deferred tax assets valuation allowance related to changes in derivative fair values (1,711)    
Increase (decrease) in other adjustments in deferred tax assets valuation allowance (5,393)    
Operating loss carryforwards, limitation as per IRC 129,521    
Alternative minimum tax credit carryforwards 426    
Accrued interest and penalties related to uncertain tax positions 74    
Expected change in uncertain tax position 0    
Internal Revenue Service (IRS)      
Tax Credit Carryforward [Line Items]      
Operating loss carryforwards 560,585    
State and Local Jurisdiction      
Tax Credit Carryforward [Line Items]      
Operating loss carryforwards 175,611    
Tax credit carryforward $ 983