Information Concerning Guarantor and Non Guarantor Subsidiaries (Details 1) (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, net	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
Intercompany receivables, net	0	0
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:
Less amounts due within one year	190	58,574
Accounts payable and accrued liabilities	145,110	175,343
Estimated fair value of derivative liabilities	1,749	12,475
Intercompany payables, net	0	0
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	0	0
Common stock	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
Parent Company [Member]
Current assets:
Cash and cash equivalents - unrestricted	107,310	117,913	175,392	175,871
Cash and cash equivalents - restricted	1,150	1,150
Trade receivables, net	0	0
Estimated fair value of derivative assets	0	22
Deferred income taxes	168	67
Other current assets	4,111	3,364
Intercompany receivables, net	1,768,661	1,744,290
Total current assets	1,881,400	1,866,806
Property and equipment, net of accumulated depreciation	39,623	38,686
Notes receivable, net of current portion	0	0
Long-term deferred financing costs	10,007	12,521
Other long-term assets	661,272	654,722
Long-term assets of discontinued operations	0	0
Total assets	2,592,302	2,572,735
Current liabilities:
Less amounts due within one year	0	58,396
Accounts payable and accrued liabilities	12,468	14,622
Estimated fair value of derivative liabilities	1,749	12,475
Intercompany payables, net	0	0
Current liabilities of discontinued operations	0	0
Total current liabilities	14,217	85,493
Long-term debt and capital lease obligations, net of current portion	1,164,947	1,100,335
Deferred income taxes	(21,559)	(26,398)
Other long-term liabilities	58,152	58,559
Long-term liabilities of discontinued operations	0	0
Commitments and contingencies
Stockholders' equity:
Preferred stock	0	0
Common stock	484	481
Additional paid-in capital	924,553	916,359
Treasury stock of 385 shares, at cost	(4,599)	(4,599)
Retained earnings	477,274	470,594
Accumulated other comprehensive loss	(21,167)	(28,089)
Total stockholders' equity	1,376,545	1,354,746
Total liabilities and stockholders' equity	2,592,302	2,572,735
Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents - unrestricted	4,053	6,485	7,910	4,158
Cash and cash equivalents - restricted	0	0
Trade receivables, net	48,977	31,793
Estimated fair value of derivative assets	0	0
Deferred income taxes	5,086	5,748
Other current assets	43,609	45,754
Intercompany receivables, net	0	0
Total current assets	101,725	89,780
Property and equipment, net of accumulated depreciation	2,157,453	2,162,759
Notes receivable, net of current portion	143,773	142,651
Long-term deferred financing costs	0	0
Other long-term assets	359,897	362,282
Long-term assets of discontinued operations	0	0
Total assets	2,762,848	2,757,472
Current liabilities:
Less amounts due within one year	190	178
Accounts payable and accrued liabilities	133,063	161,142
Estimated fair value of derivative liabilities	0	0
Intercompany payables, net	1,976,326	1,947,054
Current liabilities of discontinued operations	0	0
Total current liabilities	2,109,579	2,108,374
Long-term debt and capital lease obligations, net of current portion	209	306
Deferred income taxes	132,026	127,768
Other long-term liabilities	82,843	83,346
Long-term liabilities of discontinued operations	0	0
Commitments and contingencies
Stockholders' equity:
Preferred stock	0	0
Common stock	2,388	2,388
Additional paid-in capital	1,081,063	1,081,056
Treasury stock of 385 shares, at cost	0	0
Retained earnings	(645,260)	(645,766)
Accumulated other comprehensive loss	0	0
Total stockholders' equity	438,191	437,678
Total liabilities and stockholders' equity	2,762,848	2,757,472
Non-Guarantor Subsidiaries [Member]
Current assets:
Cash and cash equivalents - unrestricted	0	0
Cash and cash equivalents - restricted	0	0
Trade receivables, net	0	0
Estimated fair value of derivative assets	0	0
Deferred income taxes	680	680
Other current assets	0	0
Intercompany receivables, net	294,444	287,087
Total current assets	295,124	287,767
Property and equipment, net of accumulated depreciation	0	0
Notes receivable, net of current portion	0	0
Long-term deferred financing costs	0	0
Other long-term assets	0	0
Long-term assets of discontinued operations	408	401
Total assets	295,532	288,168
Current liabilities:
Less amounts due within one year	0	0
Accounts payable and accrued liabilities	0	0
Estimated fair value of derivative liabilities	0	0
Intercompany payables, net	86,779	84,323
Current liabilities of discontinued operations	327	357
Total current liabilities	87,106	84,680
Long-term debt and capital lease obligations, net of current portion	0	0
Deferred income taxes	(229)	(230)
Other long-term liabilities	0	0
Long-term liabilities of discontinued operations	451	451
Commitments and contingencies
Stockholders' equity:
Preferred stock	0	0
Common stock	1	1
Additional paid-in capital	(40,127)	(40,120)
Treasury stock of 385 shares, at cost	0	0
Retained earnings	248,330	243,386
Accumulated other comprehensive loss	0	0
Total stockholders' equity	208,204	203,267
Total liabilities and stockholders' equity	295,532	288,168
Consolidation, Eliminations [Member]
Current assets:
Cash and cash equivalents - unrestricted	0	0
Cash and cash equivalents - restricted	0	0
Trade receivables, net	0	0
Estimated fair value of derivative assets	0	0
Deferred income taxes	0	0
Other current assets	(126)	(126)
Intercompany receivables, net	(2,063,105)	(2,031,377)
Total current assets	(2,063,231)	(2,031,503)
Property and equipment, net of accumulated depreciation	0	0
Notes receivable, net of current portion	0	0
Long-term deferred financing costs	0	0
Other long-term assets	(971,389)	(965,939)
Long-term assets of discontinued operations	0	0
Total assets	(3,034,620)	(2,997,442)
Current liabilities:
Less amounts due within one year	0	0
Accounts payable and accrued liabilities	(421)	(421)
Estimated fair value of derivative liabilities	0	0
Intercompany payables, net	(2,063,105)	(2,031,377)
Current liabilities of discontinued operations	0	0
Total current liabilities	(2,063,526)	(2,031,798)
Long-term debt and capital lease obligations, net of current portion	0	0
Deferred income taxes	0	0
Other long-term liabilities	295	295
Long-term liabilities of discontinued operations	0	0
Commitments and contingencies
Stockholders' equity:
Preferred stock	0	0
Common stock	(2,389)	(2,389)
Additional paid-in capital	(1,040,936)	(1,040,936)
Treasury stock of 385 shares, at cost	0	0
Retained earnings	71,936	77,386
Accumulated other comprehensive loss	0	0
Total stockholders' equity	(971,389)	(965,939)
Total liabilities and stockholders' equity	$ (3,034,620)	$ (2,997,442)