| **Income Taxes**                     | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   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| **Income Tax Disclosure [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     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| Income Taxes                         | Income TaxesTotal income tax expense of $10.0 million, $11.0 million and $12.1 million for the years ended December 31, 2014, 2013 and 2012, respectively, was allocated to income in each year.  Income tax expense consists of the following (amounts in thousands): Years Ended December 31, 2014 2013 2012Deferred tax expense:     Federal taxes$9,081 9,267 10,318State taxes948 1,690 1,770 $10,029 10,957 12,088Total income tax expense differed from the “expected” income tax expense determined by applying the statutory federal income tax rate of 35% as follows (amounts in thousands): Years Ended December 31, 2014 2013 2012“Expected” statutory tax expense$24,246 14,939 7,437Impact of non-controlling interest attributable to non-tax paying entity(18,255) (7,977) —State income taxes, net of federal expense948 1,690 1,770Income tax effect of nondeductible entertainment expenses1,125 1,045 777Income tax effect of nondeductible lobbying expenses425 369 298Income tax effect of nondeductible officer compensation1,351 824 1,718Other, net189 67 88 $10,029 10,957 12,088The tax effects of temporary differences that give rise to significant portions of deferred tax assets and liabilities at December 31, 2014 and 2013 are summarized below (amounts in thousands): 2014 2013Current deferred tax assets, net of current deferred tax liability:   Net operating loss carryforwards$44,250 30,344Compensated absences, accrued for financial reporting purposes3,117 2,956Workers compensation and self-insurance health reserves, principally due to accrual for financial reporting purposes2,043 1,688Accounts receivable, principally due to allowance for doubtful receivables2,585 1,154Deferred revenue for financial reporting purposes2,525 2,673Other1,600 938Total current deferred tax assets$56,120 39,753Long-term deferred tax assets:   Net operating loss carryforwards$87,688 90,589Deferred revenue for financial reporting purposes33,552 35,506Alternative minimum tax credits1,735 1,895Deferred compensation expense for tax purposes in excess of amounts recognized for financial reporting purposes1,374 2,556Asset retirement obligations in excess of amounts recognized for tax purposes6,660 4,930Share-based compensation expense for financial reporting purposes in excess of amounts recognized for tax purposes1,458 1,860Other4,266 4,335Total long-term deferred tax assets136,733 141,671Long-term deferred tax liabilities:   Plant and equipment, principally due to differences in depreciation231,109 212,719Intangible assets48,768 49,761Flow-through entity deferred tax items44,728 40,667Total long-term deferred tax liabilities324,605 303,147Net long-term deferred tax liabilities$187,872 161,476At December 31, 2014, we have tax net operating loss carryforwards of $320.3 million that will begin expiring in 2020 if not utilized, and alternative minimum tax credit carryforwards of $1.7 million available to offset regular income taxes payable in future years.  Our utilization of remaining acquired net operating loss carryforwards is subject to annual limitations pursuant to Internal Revenue Code section 382 which could reduce or defer the utilization of these losses.Our tax net operating loss carryforwards are summarized below by year of expiration (amounts in thousands):Years ending December 31,Federal State2020$34,958 34,301202129,614 28,987202214,081 13,78820233,968 3,9032024722 —2025737 —2026150 —20271,010 —202839,879 39,715202948,370 47,5582031110,933 109,37620335,031 4,927203430,797 29,946Total tax net operating loss carryforwards$320,250 312,501Tax benefits associated with recorded deferred tax assets are considered to be more likely than not realizable through taxable income earned in carryback years, future reversals of existing taxable temporary differences, and future taxable income exclusive of reversing temporary differences and carryforwards. The amount of deferred tax assets considered realizable, however, could be reduced if estimates of future taxable income during the carryforward period are reduced.We file federal income tax returns in the U.S. and in various state jurisdictions. We are not subject to U.S. or state tax examinations by tax authorities for years 2010 and earlier except that certain U.S. federal income tax returns for years after 1998 are not closed by relevant statutes of limitations due to unused net operating losses reported on those income tax returns.We recognize accrued interest on unrecognized tax benefits in interest expense and penalties in selling, general and administrative expenses.  We did not have any unrecognized tax benefits as of December 31, 2014, 2013 and 2012, and accordingly, we did not recognize any interest expense.  Additionally, we recorded no penalties during the years ended December 31, 2014, 2013 and 2012.We did not record any excess tax benefit generated from stock options exercised during the years ended December 31, 2014, 2013 and 2012, since we are in a net operating loss carryforward position and the income tax deduction will not yet reduce income taxes payable.  The cumulative excess tax benefits generated for stock options exercised that have not been recognized is $3.5 million at December 31, 2014. |

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| - Definition
The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.
+ References
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