Share-based Awards and Cash-based Awards (Tables)
   | 
6 Months Ended | 
Jun. 30, 2021  | 
| Notes Tables | 
 
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| Schedule of Unvested Restricted Stock Units Roll Forward [Table Text Block] | 
  
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Restricted Stock Units  | 
 
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Weighted  | 
 
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      | 
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      | 
Average  | 
 
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  | 
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Grant Date Fair  | 
 
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Units  | 
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Value Per Unit  | 
 
Nonvested, December 31, 2020  | 
  | 
 763,688  | 
  | 
$  | 
 4.51  | 
 
Granted  | 
   | 
 698,301  | 
  | 
   | 
 4.72  | 
 
Vested  | 
   | 
 —  | 
  | 
   | 
 —  | 
 
Forfeited  | 
   | 
 (19,880)  | 
  | 
   | 
 4.51  | 
 
Nonvested, June 30, 2021  | 
   | 
 1,442,109  | 
  | 
  | 
 4.61  | 
 
 
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| Summary Of Nonvested Restricted Stock Units, Vesting Schedule [Table Text Block] | 
  
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  | 
      | 
Restricted  | 
 
  | 
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Shares  | 
 
2021  | 
   | 
 743,808  | 
 
2022  | 
   | 
 232,767  | 
 
2023  | 
  | 
 232,767  | 
 
2024  | 
  | 
 232,767  | 
 
Total  | 
   | 
 1,442,109  | 
 
 
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| Schedule of Nonvested Performance-based Units Activity [Table Text Block] | 
  
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Performance Share Units  | 
 
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Weighted  | 
 
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      | 
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      | 
Average  | 
 
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  | 
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Grant Date Fair  | 
 
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Units  | 
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Value Per Unit  | 
 
Nonvested, December 31, 2020  | 
  | 
 —  | 
  | 
$  | 
 —  | 
 
Granted  | 
   | 
 388,908  | 
  | 
   | 
 5.57  | 
 
Vested  | 
   | 
 —  | 
  | 
   | 
 —  | 
 
Forfeited  | 
   | 
 —  | 
  | 
   | 
 —  | 
 
Nonvested, June 30, 2021  | 
   | 
 388,908  | 
  | 
  | 
 5.57  | 
 
 
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| Share-based Payment Arrangement, Nonemployee Director Award Plan, Activity [Table Text Block] | 
  
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Restricted Shares  | 
 
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  | 
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Weighted  | 
 
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      | 
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      | 
Average  | 
 
  | 
  | 
  | 
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Grant Date Fair  | 
 
  | 
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Units  | 
  | 
Value Per Unit  | 
 
Nonvested, December 31, 2020  | 
  | 
 154,128  | 
  | 
$  | 
 3.64  | 
 
Granted  | 
   | 
 62,502  | 
  | 
   | 
 3.36  | 
 
Vested  | 
   | 
 (146,404)  | 
  | 
   | 
 3.51  | 
 
Nonvested, June 30, 2021  | 
   | 
 70,226  | 
  | 
  | 
 3.67  | 
 
 
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| Share-based Payment Arrangement, Cost by Plan [Table Text Block] | 
  
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Three Months Ended June 30,   | 
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Six Months Ended June 30,   | 
 
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      | 
2021  | 
      | 
2020  | 
      | 
2021  | 
      | 
2020  | 
 
Share-based compensation expense from:  | 
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Restricted stock units  | 
  | 
$  | 
 339  | 
  | 
$  | 
 949  | 
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$  | 
 676  | 
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$  | 
 1,927  | 
 
Restricted Shares  | 
  | 
   | 
 128  | 
  | 
   | 
 70  | 
  | 
   | 
 245  | 
  | 
   | 
 140  | 
 
Total  | 
  | 
$  | 
 467  | 
  | 
$  | 
 1,019  | 
  | 
$  | 
 921  | 
  | 
$  | 
 2,067  | 
 
 
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| Schedule of Incentive Compensation Expense [Table Text Block] | 
  
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Three Months Ended June 30,   | 
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Six Months Ended June 30,   | 
 
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      | 
2021  | 
      | 
2020  | 
      | 
2021  | 
      | 
2020  | 
 
Share-based compensation included in:  | 
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General and administrative expenses  | 
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$  | 
 467  | 
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$  | 
 1,019  | 
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$  | 
 921  | 
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$  | 
 2,067  | 
 
Cash-based incentive compensation included in:  | 
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   | 
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Lease operating expense (1)  | 
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   | 
 816  | 
  | 
   | 
 —  | 
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   | 
 1,655  | 
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   | 
 849  | 
 
General and administrative expenses (1)  | 
  | 
   | 
 2,676  | 
  | 
   | 
 159  | 
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   | 
 5,359  | 
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   | 
 3,790  | 
 
Total charged to operating (loss) income  | 
  | 
$  | 
 3,959  | 
  | 
$  | 
 1,178  | 
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$  | 
 7,935  | 
  | 
$  | 
 6,706  | 
 
 
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(1) | 
Includes adjustments of accruals to actual payments. | 
  
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| Performance Share Units [Member] | 
 
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| Notes Tables | 
 
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| Schedule of Share-based Payment Award, Equity Instrument Other Than Options, Valuation Assumptions [Table Text Block] | 
  
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2021 Grant Date  | 
 
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 June 28  | 
 
Expected term for performance period (in years)  | 
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 0.5  | 
  | 
 
Expected volatility  | 
  | 
 67.9  | 
%  | 
 
Risk-free interest rate  | 
  | 
 0.1  | 
%  | 
 
 
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| Long Term Cash Based Awards [Member] | 
 
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| Notes Tables | 
 
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| Schedule of Share-based Payment Award, Equity Instrument Other Than Options, Valuation Assumptions [Table Text Block] | 
  
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  | 
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2021 Grant Date  | 
 
  | 
  | 
 June 28  | 
 
Expected term for performance period (in years)  | 
  | 
 0.5  | 
  | 
 
Expected volatility  | 
  | 
 67.9  | 
%  | 
 
Risk-free interest rate  | 
  | 
 0.1  | 
%  | 
 
Expected term for cash payment (in years)  | 
  | 
 2.3  | 
  | 
 
Discount rate used to discount expected cash payment  | 
  | 
 12.1  | 
%  | 
 
 
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