Annual report pursuant to Section 13 and 15(d)

Income Taxes - Additional Information (Details)

v3.10.0.1
Income Taxes - Additional Information (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Income Tax Expense (Benefit), Continuing Operations [Abstract]        
Federal statutory income tax rate   21.00% 35.00% 35.00%
Cash paid for income taxes   $ 138 $ 185 $ 310
Income tax refund received   11,126 11,906 7,796
Current income taxes receivable $ 13,006 54,076 13,006  
Increase and (decrease) in valuation allowance (105,900) (53,800) (118,600)  
Income tax expense (benefit) adjustment $ 500      
Minimum        
Income Tax Expense (Benefit), Continuing Operations [Abstract]        
Estimated recognized tax benefits   11,500    
Maximum        
Income Tax Expense (Benefit), Continuing Operations [Abstract]        
Estimated recognized tax benefits   12,000    
Tax Year 2016, 2017 and 2018        
Income Tax Expense (Benefit), Continuing Operations [Abstract]        
Income tax refund received related to NOL claim   $ 11,100 $ 11,900 $ 7,800
Earliest Tax Year        
Income Tax Expense (Benefit), Continuing Operations [Abstract]        
Tax years under examination   2013    
Latest Tax Year        
Income Tax Expense (Benefit), Continuing Operations [Abstract]        
Tax years under examination   2018