| **Consolidated Statement of Cash Flows Supplemental Disclosures ( Non-cash investing and financing activities) (Details) (USD $)In Thousands, unless otherwise specified** | 6 Months Ended |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------|
||
| **Supplemental Cash Flow Elements [Abstract]**                                                                                                                             |           |   |
| Non-cash additions for purchases of property and equipment                                                                                                                 | $ 25,114       | $ 13,740 |
| Net capital lease obligation                                                                                                                                               | 9,386          | 0 |
| Distribution to non-controlling interest                                                                                                                                   | 4,167          | 0 |
| Asset retirement obligation additions to property and equipment                                                                                                            | 361            | 1,066 |
| Deferred compensation distribution denominated in shares                                                                                                                   | $ 617          | $ 621 |

| X                                                                                                                                                                                                                                                                      |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Distribution to Non-controlling Interest
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of asset retirement obligations incurred during the period.
+ References
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Future cash outflow to pay for purchases of fixed assets that have occurred.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The increase during the period in capital lease obligations due to entering into new capital leases.
+ References
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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The value of the noncash (or part noncash) consideration given (for example, liability, equity) in a transaction. Noncash is defined as transactions during a period that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of a transaction not resulting in cash receipts or cash payments in the period.
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