Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Current assets
Cash and cash equivalents	$ 47,125	$ 43,822
Trade receivables, net of allowance for doubtful accounts of $3,139 and $3,199 (including related parties of $8,374 and $7,102)	53,721	57,043
Deferred income taxes	6,100	6,100
Prepaid expenses and other current assets (including related parties of $274 and $274)	4,892	4,087
Total current assets	111,838	111,052
Property and equipment, net of accumulated depreciation of $186,943 and $184,084	57,709	58,765
Intangible assets subject to amortization, net of accumulated amortization of $72,304 and $71,678 (including related parties of $17,978 and $18,559)	19,186	19,812
Intangible assets not subject to amortization	220,701	220,701
Goodwill	36,647	36,647
Deferred income taxes	81,894	83,856
Other assets	6,802	7,404
Total assets	534,777	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 $3,938 and $3,994)	24,313	31,246
Total current liabilities	28,181	35,114
Long-term debt, less current maturities	359,375	360,313
Other long-term liabilities	7,320	6,786
Total liabilities	394,876	402,213
Commitments and contingencies (note 4)
Stockholders' equity
Additional paid-in capital	927,497	927,377
Accumulated deficit	(787,208)	(791,596)
Accumulated other comprehensive income (loss)	(397)	234
Total stockholders' equity	139,901	136,024
Total liabilities and stockholders' equity	534,777	538,237
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