Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets
Cash and cash equivalents	$ 47,924	$ 31,260
Trade receivables, net of allowance for doubtful accounts of $3,040 and $3,100 (including related parties of $5,534 and $10,882)	66,399	64,956
Prepaid expenses and other current assets (including related parties of $274 and $274)	5,705	5,295
Total current assets	120,028	101,511
Property and equipment, net of accumulated depreciation of $198,282 and $193,532	57,874	56,784
Intangible assets subject to amortization, net of accumulated amortization of $78,234 and $74,697 (including related parties of $13,918 and $16,239)	16,656	20,193
Intangible assets not subject to amortization	220,701	220,701
Goodwill	50,081	50,081
Deferred income taxes	57,929	72,458
Other assets	4,919	6,039
Total assets	528,188	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 $3,791 and $3,695)	29,669	32,195
Total current liabilities	33,537	36,063
Long-term debt, less current maturities	312,813	336,563
Other long-term liabilities	14,565	9,583
Total liabilities	$ 360,915	$ 382,209
Commitments and contingencies (note 11)
Stockholders' equity
Additional paid-in capital	$ 910,228	$ 912,161
Accumulated deficit	(738,849)	(764,474)
Accumulated other comprehensive income (loss)	(4,115)	(2,138)
Total stockholders' equity	167,273	145,558
Total liabilities and stockholders' equity	528,188	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