CONDENSED CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Current assets:
Cash and cash equivalents	$ 349,835	$ 304,866
Accounts receivable, net of allowance for doubtful accounts of $1,817 and $1,871, respectively	33,505	30,628
Prepaid expenses and other current assets	22,481	18,777
Total current assets	405,821	354,271
Property and equipment, net	353,663	341,193
Deferred tax assets - noncurrent	50,122	50,861
Deposits and other assets - $447 and $448 restricted, respectively	13,181	8,776
Total assets	822,787	755,101
Current liabilities:
Accounts payable	16,969	14,098
Accrued liabilities	34,754	31,465
Convertible senior notes - current portion, net of discount of $3,099 (Note 3)		88,879
Current maturities, capital lease obligations	8,341	9,252
Total current liabilities	60,064	143,694
Senior secured notes including premium of $4,835 and $5,423, respectively	244,835	245,423
Senior unsecured notes	200,000
Capital lease obligations, net of current maturities	155,899	152,527
Other long term liabilities	21,367	19,965
Total liabilities	682,165	561,609
Commitments and contingencies:
Stockholders' equity:
Common stock, $0.001 par value; 75,000,000 shares authorized; 46,466,355 and 47,334,218 shares issued and outstanding, respectively	46	47
Additional paid-in capital	480,794	508,256
Accumulated other comprehensive income - foreign currency translation	1,630	2,136
Accumulated deficit	(341,848)	(316,947)
Total stockholders' equity	140,622	193,492
Total liabilities and stockholders' equity	$ 822,787	$ 755,101