| **Income Taxes (Tables)**                                                 | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
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| **Income Taxes [Abstract]**                                               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
| Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] |    Years Ended December 31,   2012 2011 2010 Deferred tax expense:       Federal taxes$ 10,318  6,264  7,846 State taxes  1,770  1,141  1,402  $ 12,088  7,405  9,248                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
| Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]   |    Years Ended December 31,   2012 2011 2010 “Expected” statutory tax expense$ 7,437  4,500  6,215 State income taxes, net of federal  expense   1,770  1,141  1,129 Income tax effect of nondeductible  entertainment expenses  777  737  775 Income tax effect of nondeductible   lobbying expenses  298  327  405 Income tax effect of nondeductible officer  compensation  1,718  758  722 Other, net  88  (58)  2  $ 12,088  7,405  9,248                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
| ScheduleOfDeferredTaxAssetsAndLiabilitiesTableTextBlock                   |     2012 2011 Current deferred tax assets, net of current deferred tax liability:      Net operating loss carryforwards$ 3,952  7,796  Compensated absences, accrued for financial reporting  purposes  2,605  2,664  Workers compensation and self-insurance health reserves,  principally due to accrual for financial reporting purposes  1,357  1,068  Accounts receivable, principally due to allowance for doubtful  receivables  1,319  2,379  Deferred compensation expense for tax purposes in  excess of amounts recognized for financial reporting  purposes  32  131  Deferred revenue for financial reporting purposes  2,734  1,362  Other  898  155  Total current deferred tax assets$ 12,897  15,555        Long-term deferred tax assets:      Net operating loss carryforwards$ 116,034  119,762  Deferred revenue for financial reporting purposes  36,316  18,097  Alternative minimum tax credits  1,895  1,895  Deferred compensation expense for tax purposes in  excess of amounts recognized for financial reporting  purposes  2,543  2,581  Asset retirement obligations in excess of amounts recognized  for tax purposes  6,680  6,248  Share-based compensation expense for financial reporting  purposes in excess of amounts recognized for tax purposes  1,675  4,394  Other  3,353  469  Total long-term deferred tax assets  168,496  153,446        Long-term deferred tax liabilities:      Plant and equipment, principally due to differences in depreciation  233,530  211,172  Intangible assets  58,627  56,508  Total long-term deferred tax liabilities  292,157  267,680  Net long-term deferred tax liabilities$ 123,661  114,234 |
| Summary of Operating Loss Carryforwards [Table Text Block]                |  Years ending December 31, Federal State 2020$ 43,863  42,768 2021  29,614  28,987 2022  14,081  13,788 2023  3,968  3,903 2024  722  - 2025  737  - 2026  150  - 2027  1,010  - 2028  39,879  39,715 2029  48,370  47,558 2031  110,933  109,376 Total tax net operating loss carryforwards$ 293,327  286,095                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |

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| - Definition
Tabular disclosure of the components of income tax expense attributable to continuing operations for each year presented including, but not limited to: current tax expense (benefit), deferred tax expense (benefit), investment tax credits, government grants, the benefits of operating loss carryforwards, tax expense that results from allocating certain tax benefits either directly to contributed capital or to reduce goodwill or other noncurrent intangible assets of an acquired entity, adjustments of a deferred tax liability or asset for enacted changes in tax laws or rates or a change in the tax status of the entity, and adjustments of the beginning-of-the-year balances of a valuation allowance because of a change in circumstances that causes a change in judgment about the realizability of the related deferred tax asset in future years.
+ References
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| - Definition
Tabular disclosure of the components of net deferred tax asset or liability recognized in an entity's statement of financial position, including the following: the total of all deferred tax liabilities, the total of all deferred tax assets, the total valuation allowance recognized for deferred tax assets.
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Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32537-109319
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| - Definition
Tabular disclosure of the reconciliation using percentage or dollar amounts of the reported amount of income tax expense attributable to continuing operations for the year to the amount of income tax expense that would result from applying domestic federal statutory tax rates to pretax income from continuing operations.
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| - Definition
Tabular disclosure of pertinent information, such as tax authority, amounts, and expiration dates, of net operating loss carryforwards, including an assessment of the likelihood of utilization.
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Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 48 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.  This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32559-109319
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