Annual report pursuant to Section 13 and 15(d)

Long-term Debt - Secured and Unsecured Notes (Details)

v3.20.4
Long-term Debt - Secured and Unsecured Notes (Details) - USD ($)
1 Months Ended 12 Months Ended
Dec. 11, 2017
Mar. 31, 2019
Dec. 31, 2020
Dec. 31, 2019
May 04, 2016
Senior Notes | 6.75% Senior Secured Notes due 2022          
Debt Instrument [Line Items]          
Debt instrument face amount         $ 625,000,000
Debt instrument stated interest rate         6.75%
Senior Notes | 6.75% Senior Secured Notes due 2022 | Debt Instrument, Redemption, Period Two          
Debt Instrument [Line Items]          
Debt instrument, redemption price percentage     101.688%    
Senior Notes | 6.75% Senior Secured Notes due 2022 | Debt Instrument, Redemption, Period Three          
Debt Instrument [Line Items]          
Debt instrument, redemption price percentage     100.00%    
Unsecured Notes | 5.75% Senior Unsecured Notes due 2025          
Debt Instrument [Line Items]          
Debt instrument face amount $ 300,000,000        
Debt instrument stated interest rate 5.75%        
Debt instrument, redemption price percentage 105.75%   100.00%    
Repayment of note   $ 10,550,000      
Write off of deferred financing costs     $ 2,085,000    
Write-off of original issue discount     $ 1,186,000    
Debt instrument, call premium 1.00%        
Unsecured Notes | 5.75% Senior Unsecured Notes due 2025 | Change of Control          
Debt Instrument [Line Items]          
Debt instrument, redemption price percentage     101.00%    
Unsecured Notes | 5.75% Senior Unsecured Notes due 2025 | Debt Instrument, Redemption, Period One          
Debt Instrument [Line Items]          
Debt instrument, redemption price percentage     102.875%    
Unsecured Notes | 5.75% Senior Unsecured Notes due 2025 | Debt Instrument, Redemption, Period Two          
Debt Instrument [Line Items]          
Debt instrument, redemption price percentage     101.438%    
Unsecured Notes | 5.75% Senior Unsecured Notes due 2025 | Debt Instrument, Redemption, Period Three          
Debt Instrument [Line Items]          
Debt instrument, redemption price percentage     100.00%    
Unsecured Notes | 5.75% Senior Unsecured Notes due 2025 | Minimum | Event of Default          
Debt Instrument [Line Items]          
Potential percentage of principal redeemed       30.00%  
Unsecured Notes | 5.75% Senior Unsecured Notes due 2025 | Maximum | Exercise of Call Option          
Debt Instrument [Line Items]          
Potential percentage of principal redeemed 40.00%        
United States Treasury [Member] | Unsecured Notes | 5.75% Senior Unsecured Notes due 2025          
Debt Instrument [Line Items]          
Variable rate on spread 0.50%