XML 58 R43.htm IDEA: XBRL DOCUMENT v3.21.1
Financial Instruments - Schedule of Carrying Amounts and Estimated Fair Values of Financial Instruments (Parenthetical) (Details)
3 Months Ended 12 Months Ended
Mar. 31, 2021
Dec. 31, 2020
Bank Credit Facility – matures May 2022    
Debt Instrument [Line Items]    
Senior notes, maturity date May 10, 2022 May 10, 2022
12.00% Second-Priority Senior Secured Notes – due January 2026    
Debt Instrument [Line Items]    
Debt instrument interest rate 12.00% 12.00%
Senior notes, maturity date Jan. 15, 2026 Jan. 15, 2026
11.00% Second-Priority Senior Secured Notes – due April 2022    
Debt Instrument [Line Items]    
Debt instrument interest rate 11.00% 11.00%
Senior notes, maturity date Apr. 03, 2022 Apr. 03, 2022
7.50% Senior Notes – due May 2022    
Debt Instrument [Line Items]    
Debt instrument interest rate 7.50% 7.50%
Senior notes, maturity date May 31, 2022 May 31, 2022