CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 274,319	$ 203,591
Accounts receivable, net of allowance for doubtful accounts of $1,734 and $1,757, respectively	33,598	30,718
Prepaid expenses and other current assets	19,706	17,030
Total current assets	327,623	251,339
Property and equipment	1,136,470	1,070,111
Accumulated depreciation and amortization	(774,829)	(709,975)
Total property and equipment, net	361,641	360,136
Deferred tax assets	42,241	45,142
Deposits and other assets ($128 and $355 restricted, respectively)	6,387	6,199
Total assets	737,892	662,816
Current liabilities:
Accounts payable	11,551	12,401
Accrued and other current liabilities	47,149	38,355
Installment payment agreement, current portion, net of discount of $204 and $678, respectively	2,587	11,901
Current maturities, capital lease obligations	6,626	6,247
Total current liabilities	67,913	68,904
Senior secured 2022 notes, net of unamortized debt costs of $2,257 and $1,252, respectively and including premium of $462 in 2016	373,205	248,748
Senior unsecured 2021 notes, net of unamortized debt costs of $2,575 and $3,305, respectively	186,650	196,695
Capital lease obligations, net of current maturities	135,335	129,763
Other long term liabilities	28,043	30,977
Total liabilities	791,146	675,087
Commitments and contingencies:
Stockholders' equity:
Common stock, $0.001 par value; 75,000,000 shares authorized; 45,478,787 and 45,198,718 shares issued and outstanding, respectively	45	45
Additional paid-in capital	442,799	434,161
Accumulated other comprehensive income	(17,193)	(14,693)
Accumulated deficit	(478,905)	(431,784)
Total stockholders' deficit	(53,254)	(12,271)
Total liabilities and stockholders' equity	$ 737,892	$ 662,816