| **Consolidated Statement of Cash Flows Supplemental Disclosures ( Non-cash investing and financing activities) (Details) (USD $)In Thousands, unless otherwise specified** | 12 Months Ended |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------|-----------------|
||
| **Supplemental Cash Flow Elements [Abstract]**                                                                                                                             |            |   |   |
| Non-cash additions for purchases of property and equipment                                                                                                                 | $ 17,230        | $ 9,010 | $ 7,233 |
| Asset retirement obligation additions to property and equipment                                                                                                            | 5,292           | 660 | 613 |
| Deferred compensation distribution denominated in shares                                                                                                                   | 621             | 511 | 0 |
| Net assets acquired with equity in AWN                                                                                                                                     | $ 267,642       | $ 0 | $ 0 |

| 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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|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of assets that an Entity acquires in a noncash (or part noncash) acquisition that are not presented as a separate disclosure or not otherwise listed in the existing taxonomy. Noncash is defined as information about all investing and financing activities of an enterprise during a period that affect recognized assets or liabilities but that do not result in cash receipts or cash payments in the period.
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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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