Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Current assets
Cash and cash equivalents	$ 49,864	$ 31,260
Trade receivables, net of allowance for doubtful accounts of $2,962 and $3,100 (including related parties of $1,140 and $10,882)	48,947	64,956
Deferred income taxes	5,900	5,900
Prepaid expenses and other current assets (including related parties of $274 and $274)	5,776	5,295
Total current assets	110,487	107,411
Property and equipment, net of accumulated depreciation of $196,590 and $193,532	56,948	56,784
Intangible assets subject to amortization, net of accumulated amortization of $75,581 and $74,697 (including related parties of $15,658 and $16,239)	19,309	20,193
Intangible assets not subject to amortization	220,701	220,701
Goodwill	50,081	50,081
Deferred income taxes	64,328	66,558
Other assets	5,770	6,039
Total assets	527,624	527,767
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 $3,847 and $3,695)	27,432	32,195
Total current liabilities	31,300	36,063
Long-term debt, less current maturities	335,625	336,563
Other long-term liabilities	11,451	9,583
Total liabilities	378,376	382,209
Commitments and contingencies (note 4)
Stockholders' equity
Additional paid-in capital	911,737	912,161
Accumulated deficit	(759,190)	(764,474)
Accumulated other comprehensive income (loss)	(3,308)	(2,138)
Total stockholders' equity	149,248	145,558
Total liabilities and stockholders' equity	527,624	527,767
Class A common stock
Stockholders' equity
Common stock	6	6
Class B common stock
Stockholders' equity
Common stock	2	2
Class U common stock
Stockholders' equity
Common stock	$ 1	$ 1