CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 203,591	$ 287,790
Accounts receivable, net of allowance for doubtful accounts of $1,757 and $1,707, respectively	30,718	33,089
Prepaid expenses and other current assets	17,030	14,758
Total current assets	251,339	335,637
Property and equipment:
Property and equipment	1,070,111	1,047,590
Accumulated depreciation and amortization	(709,975)	(686,829)
Total property and equipment, net	360,136	360,761
Deferred tax assets - noncurrent	45,142	52,967
Deposits and other assets ($355 and $389 restricted, respectively)	6,199	5,549
Total assets	662,816	754,914
Current liabilities:
Accounts payable	12,401	13,287
Accrued and other current liabilities	38,355	32,151
Installment payment agreement, current portion, net of discount of $678	11,901
Current maturities, capital lease obligations	6,247	14,594
Total current liabilities	68,904	60,032
Senior unsecured 2021 notes	196,695	196,180
Capital lease obligations, net of current maturities	129,763	151,944
Other long term liabilities	30,977	21,775
Total liabilities	$ 675,087	$ 671,120
Commitments and contingencies:
Stockholders' equity:
Common stock, $0.001 par value; 75,000,000 shares authorized; 45,198,718 and 46,398,729 shares issued and outstanding, respectively	$ 45	$ 46
Additional paid-in capital	434,161	460,576
Accumulated other comprehensive income	(14,693)	(6,462)
Accumulated deficit	(431,784)	(370,366)
Total stockholders' (deficit) equity	(12,271)	83,794
Total liabilities and stockholders' equity	662,816	754,914
Senior Secured 2022 Notes Member
Current liabilities:
Senior secured notes	$ 248,748
Senior Secured 2018 Notes Member
Current liabilities:
Senior secured notes		$ 241,189