Condensed Consolidated Balance Sheets (Unaudited) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents - unrestricted	$ 29,504	$ 44,388	$ 111,363	$ 124,398
Cash and cash equivalents - restricted	1,150	1,150
Trade receivables, less allowance of $540 and $719, respectively	54,194	41,939
Deferred income taxes	4,993	8,641
Other current assets	44,397	48,538
Total current assets	134,238	144,656
Property and equipment, net of accumulated depreciation	2,200,616	2,209,127
Notes receivable, net of current portion	145,271	142,567
Long-term deferred financing costs	13,602	15,947
Other long-term assets	52,285	50,713
Long-term assets of discontinued operations	335	390
Total assets	2,546,347	2,563,400
Current liabilities:
Current portion of long-term debt and capital lease obligations	750	755
Accounts payable and accrued liabilities	151,735	168,975
Current liabilities of discontinued operations	147	186
Total current liabilities	152,632	169,916
Long-term debt and capital lease obligations, net of current portion	1,034,456	1,073,070
Deferred income taxes	119,817	108,219
Other long-term liabilities	170,779	166,209
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
Common stock, $.01 par value, 150,000 shares authorized, 49,098 and 48,428 shares issued and outstanding, respectively	491	484
Additional paid-in capital	937,592	929,904
Treasury stock of 385 shares, at cost	(4,599)	(4,599)
Retained earnings	170,759	155,777
Accumulated other comprehensive loss	(36,031)	(36,031)
Total stockholders' equity	1,068,212	1,045,535
Total liabilities and stockholders' equity	$ 2,546,347	$ 2,563,400