Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2011	Dec. 31, 2010	Jun. 30, 2010	Dec. 31, 2009
Current assets:
Cash and cash equivalents - unrestricted	$ 111,363	$ 124,398	$ 183,302	$ 180,029
Cash and cash equivalents - restricted	1,150	1,150
Trade receivables, less allowance of $660 and $ 882, respectively	48,977	31,793
Estimated fair value of derivative assets	0	22
Deferred income taxes	5,934	6,495
Other current assets	47,594	48,992
Total current assets	215,018	212,850
Property and equipment, net of accumulated depreciation	2,197,076	2,201,445
Notes receivable, net of current portion	143,773	142,651
Long-term deferred financing costs	10,007	12,521
Other long-term assets	49,780	51,065
Long-term assets of discontinued operations	408	401
Total assets	2,616,062	2,620,933
Current liabilities:
Current portion of long-term debt and capital lease obligations	190	58,574
Accounts payable and accrued liabilities	145,110	175,343
Estimated fair value of derivative liabilities	1,749	12,475
Current liabilities of discontinued operations	327	357
Total current liabilities	147,376	246,749
Long-term debt and capital lease obligations, net of current portion	1,165,156	1,100,641
Deferred income taxes	110,238	101,140
Other long-term liabilities	141,290	142,200
Long-term liabilities of discontinued operations	451	451
Commitments and contingencies
Stockholders' equity:
Preferred stock, $.01 par value, 100,000 shares authorized, no shares issued or outstanding	0	0
Common stock, $.01 par value, 150,000 shares authorized, 48397 and 48,144 shares issued and outstanding, respectively	484	481
Additional paid-in capital	924,553	916,359
Treasury stock of 385 shares, at cost	(4,599)	(4,599)
Retained earnings	152,280	145,600
Accumulated other comprehensive loss	(21,167)	(28,089)
Total stockholders' equity	1,051,551	1,029,752
Total liabilities and stockholders' equity	$ 2,616,062	$ 2,620,933