Note 9 - Share-based Compensation and Cash-based Incentive Compensation - Summary of Compensation Expense Related to Share-Based Awards and Cash-Based Awards (Details) - USD ($) $ in Thousands |
3 Months Ended | 9 Months Ended | |||||
|---|---|---|---|---|---|---|---|
Sep. 30, 2019 |
Sep. 30, 2018 |
Sep. 30, 2019 |
Sep. 30, 2018 |
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| Share-based compensation | $ 1,248 | $ 1,373 | $ 2,429 | $ 3,808 | |||
| Total charged to operating income | 3,599 | 3,744 | 8,397 | 11,645 | |||
| General and Administrative Expense [Member] | |||||||
| Share-based compensation | 1,248 | 1,373 | 2,429 | 3,808 | |||
| Lease operating expense (1) | [1] | 1,679 | 1,534 | 5,017 | 5,597 | ||
| Lease Operating Expense [Member] | |||||||
| Lease operating expense (1) | [1] | $ 672 | $ 837 | $ 951 | $ 2,240 | ||
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| X | ||||||||||
- Definition Amount of noncash expense for share-based payment arrangement. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Definition Cash-based incentive compensation charged to operating income (loss). No definition available.
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| X | ||||||||||
- Definition The total amount of share-based and cash-based incentive compensation charged to operating income. No definition available.
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| X | ||||||||||
- Details
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| X | ||||||||||
- Details
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