Consolidated Statements Of Cash Flows (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 121,988	$ 113,488
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	80,883	78,937
Goodwill impairment		1,684
Amortization of debt issuance costs and other non-cash interest	3,234	3,197
Deferred income taxes	16,389	19,368
Income tax benefit of equity compensation	(1,889)	(2,602)
Non-cash equity compensation	7,788	7,326
Other non-cash items	1,327	510
Changes in assets and liabilities, net:
Accounts receivable, prepaid expenses and other assets	47,439	(108,675)
Accounts payable, accrued expenses and other liabilities	(20,221)	23,405
Income taxes payable	1,060	2,594
Net cash provided by operating activities	257,998	139,232
CASH FLOWS FROM INVESTING ACTIVITIES:
Expenditures for facility development and expansions	(37,602)	(88,012)
Expenditures for other capital improvements	(30,331)	(24,960)
Decrease in restricted cash	1,749
Proceeds from sale of assets	829	64
Increase in other assets	(1,752)	(1,196)
Payments received on direct financing lease	1,024	907
Net cash used in investing activities	(66,083)	(113,197)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of debt	273,623	116,167
Principal repayments of debt	(221,589)	(30,000)
Income tax benefit of equity compensation	1,889	2,602
Purchase and retirement of common stock	(225,300)	(131,409)
Proceeds from exercise of stock options	1,911	5,136
Net cash used in financing activities	(169,466)	(37,504)
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	22,449	(11,469)
CASH AND CASH EQUIVALENTS, beginning of period	25,509	45,908
CASH AND CASH EQUIVALENTS, end of period	47,958	34,439
Cash paid during the period for:
Interest (net of amounts capitalized of $894 and $3,744 in 2011 and 2010, respectively)	52,823	50,338
Income taxes	$ 58,092	$ 44,213