Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current assets
Cash and cash equivalents	$ 31,260	$ 43,822
Trade receivables, net of allowance for doubtful accounts of $3,100 and $3,199 (including related parties of $10,882 and $7,102)	64,956	57,043
Deferred income taxes	5,900	6,100
Prepaid expenses and other current assets (including related parties of $274 and $274)	5,295	4,087
Total current assets	107,411	111,052
Property and equipment, net of accumulated depreciation of $193,532 and $184,084	56,784	58,765
Intangible assets subject to amortization, net of accumulated amortization of $74,697 and $71,678 (including related parties of $16,239 and $18,559)	20,193	19,812
Intangible assets not subject to amortization	220,701	220,701
Goodwill	50,081	36,647
Deferred income taxes	66,558	83,856
Other assets	6,039	7,404
Total assets	527,767	538,237
Current liabilities
Current maturities of long-term debt	3,750	3,750
Advances payable, related parties	118	118
Accounts payable and accrued expenses (including related parties of $3,695 and $3,994)	32,195	31,246
Total current liabilities	36,063	35,114
Long-term debt, less current maturities	336,563	360,313
Other long-term liabilities	9,583	6,786
Total liabilities	382,209	402,213
Commitments and contingencies (note 11)
Stockholders' equity
Additional paid-in capital	912,161	927,377
Accumulated deficit	(764,474)	(791,596)
Accumulated other comprehensive income (loss)	(2,138)	234
Total stockholders' equity	145,558	136,024
Total liabilities and stockholders' equity	527,767	538,237
Class A common stock
Stockholders' equity
Common stock	6	6
Total stockholders' equity	6	6
Class B common stock
Stockholders' equity
Common stock	2	2
Total stockholders' equity	2	2
Class U common stock
Stockholders' equity
Common stock	1	1
Total stockholders' equity	$ 1	$ 1