| SIGNIFICANT ACCOUNTING POLICIES (Tables)
 | 12 Months Ended | 
| Dec. 31, 2022 | 
|---|
| Notes Tables |  | 
| Schedules of Concentration of Risk, by Risk Factor [Table Text Block] |  
|  |  |  |  |  |  |  |  |  
|  |  | Year Ended December 31,  |   |  
|  |      | 2022 |      | 2021 |      | 2020 |   |  
| Customer |   |    |   |    |   |    |  |  
| BP Products North America |   |  31 | % |  34 | % |  39 | % |  
| Chevron - Texaco |  |  13 | % |  14 | % | ** |  |  
| Mercuria Energy America Inc. |   | ** |  | ** |  |  10 | % |  
| Williams Field Services |   | ** |  |  11 | % |  13 | % |        | 
| Accounts Receivable, Allowance for Credit Loss [Table Text Block] | The following table describes the balance and changes to the allowance for credit losses (in thousands): 
|  |  |  |  |  |  |  |  |  |  |  
|  |      | 2022 |      | 2021 |      | 2020 |  
| Allowance for credit losses, beginning of period |  | $ |  10,046 |  | $ |  9,123 |  | $ |  9,898 |  
| Additional provisions for the year |  |   |  3,085 |  |   |  2,192 |  |   |  417 |  
| Uncollectible accounts written off or collected |  |   |  (1,069) |  |   |  (1,269) |  |   |  (1,192) |  
| Allowance for credit losses, end of period |  | $ |  12,062 |  | $ |  10,046 |  | $ |  9,123 |   | 
| Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Table Text Block] |  
|  |  |  |  |  |  |  |  
|  |  | December 31,  |  
|  |      | 2022 |      | 2021 |  
| Derivatives(1) (Note 10) |  | $ |  4,954 |  | $ |  21,086 |  
| Unamortized insurance/bond premiums |  |   |  6,046 |  |   |  5,400 |  
| Prepaid deposits related to royalties |  |   |  9,139 |  |   |  8,441 |  
| Prepayment to vendors |  |   |  1,767 |  |   |  4,522 |  
| Prepayments to joint interest partners |  |  |  1,717 |  |  |  2,808 |  
| Debt issue costs |  |  |  687 |  |  |  1,065 |  
| Other |  |   |  33 |  |   |  57 |  
| Prepaid expenses and other assets |  | $ |  24,343 |  | $ |  43,379 |        
|  | (1) | Includes closed contracts which have not yet settled and the current portion of open contracts. | 
 | 
| Property, Plant and Equipment [Table Text Block] | The following table provides the components of Oil and natural gas properties and other, net (in thousands): 
|  |  |  |  |  |  |  |  
|  |  | December 31,  |  
|  |      | 2022 |      | 2021 |  
| Oil and natural gas properties and equipment |  | $ |  8,813,404 |  | $ |  8,636,408 |  
| Furniture, fixtures and other |  |   |  20,915 |  |   |  20,844 |  
| Total property and equipment |  |   |  8,834,319 |  |   |  8,657,252 |  
| Less: Accumulated depreciation, depletion, amortization and impairment |  |   |  (8,099,104) |  |   |  (7,992,000) |  
| Oil and natural gas properties and other, net |  | $ |  735,215 |  | $ |  665,252 |   | 
| Schedule of Other Assets, Noncurrent [Table Text Block] | The major categories recorded in Other assets are presented in the following table (in thousands): 
|  |  |  |  |  |  |  |  
|  |  | December 31,  |  
|  |      | 2022 |      | 2021 |  
| Right-of-Use assets |  | $ |  10,364 |  | $ |  10,602 |  
| Investment in White Cap, LLC |  |   |  2,453 |  |   |  2,533 |  
| Proportional consolidation of Monza (Note 5) |  |   |  9,321 |  |   |  2,511 |  
| Derivatives(1) (Note 10) |  |   |  23,236 |  |   |  34,435 |  
| Other |  |   |  2,175 |  |   |  1,091 |  
| Total other assets (long-term) |  | $ |  47,549 |  | $ |  51,172 |       
|  | (1) | Includes open contracts. | 
 | 
| Schedule of Accrued Liabilities [Table Text Block] | The major categories recorded in Accrued liabilities are presented in the following table (in thousands): 
|  |  |  |  |  |  |  |  
|  |  | December 31,  |  
|  |      | 2022 |      | 2021 |  
| Accrued interest |  | $ |  8,967 |  | $ |  10,154 |  
| Accrued salaries/payroll taxes/benefits |  |   |  15,097 |  |   |  9,617 |  
| Litigation accruals |  |   |  396 |  |   |  646 |  
| Lease liability |  |   |  1,628 |  |   |  1,115 |  
| Derivatives(1) (Note 10) |  |   |  46,595 |  |   |  81,456 |  
| Other |  |   |  1,358 |  |   |  3,152 |  
| Total accrued liabilities |  | $ |  74,041 |  | $ |  106,140 |        
|  | (1) | Includes closed contracts which have not yet settled. | 
 | 
| Other Noncurrent Liabilities [Table Text Block] | The major categories recorded in Other liabilities are presented in the following table (in thousands):  
|  |  |  |  |  |  |  |  
|  |  | December 31,  |  
|  |      | 2022 |      | 2021 |  
| Dispute related to royalty deductions |  | $ |  4,937 |  | $ |  5,177 |  
| Derivatives (Note 10) |  |   |  43,061 |  |   |  37,989 |  
| Lease liability |  |   |  10,527 |  |   |  11,227 |  
| Other |  |   |  609 |  |   |  996 |  
| Total other liabilities (long-term) |  | $ |  59,134 |  | $ |  55,389 |   |