FRESH START ACCOUNTING (Narrative) (Details) - USD ($) $ in Thousands  | 
May 17, 2021  | 
May 16, 2021  | 
|---|---|---|
| Reorganization, Chapter 11 [Line Items] | ||
| Reorganization value of Successor assets | $ 2,252,990 | $ 2,300,000 | 
| Liabilities subject to compromise allowed claims | $ 3,100,000 | |
| Enterprise Value | 1,600,000 | |
| Minimum | ||
| Reorganization, Chapter 11 [Line Items] | ||
| Enterprise Value | 1,300,000 | |
| Maximum | ||
| Reorganization, Chapter 11 [Line Items] | ||
| Enterprise Value | 1,900,000 | |
| Investment in Grizzly Oil Sands ULC | Fresh Start Adjustments | ||
| Reorganization, Chapter 11 [Line Items] | ||
| Reduction in equity method investment | $ 27,000 | 
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- Definition Enterprise Value No definition available. 
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- Definition Increase (Decrease) In Equity Method Investments No definition available. 
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- Definition Reorganization, Post-Petition Liabilities And Allowed Claims No definition available. 
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available. 
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- Definition Amount attributed to the reconstituted entity, as well as the expected net realizable value of those assets that will be disposed before reconstitution occurs. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef 
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