Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Cash Flows from Operating Activities:
Net income	$ 37,035	$ 69,196
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	19,081	16,465
Provision for doubtful accounts	5,290	8,808
Non-cash compensation	5,115	5,681
401(k) employer match	3,332	11,467
Loss on disposal of property and equipment	1,313	2,019
Deferred income taxes	3,708	6,074
Equity in earnings of unconsolidated joint ventures	(789)	(1,522)
Amortization of deferred debt issuance costs	788	788
Return on equity investment	540	840
Changes in operating assets and liabilities, net of impact of acquisitions:
Patient accounts receivable	(3,320)	(10,395)
Other current assets	10,117	11,256
Other assets	(6,364)	(2,915)
Accounts payable	(357)	5,368
Accrued expenses	2,398	1,641
Other long-term obligations	(1,374)	663
Net cash provided by operating activities	76,513	125,434
Cash Flows from Investing Activities:
Proceeds from sale of deferred compensation plan assets	853	2,340
Purchases of deferred compensation plan assets	(379)	(1,018)
Purchases of property and equipment	(26,032)	(23,910)
Acquisitions of businesses, net of cash acquired	(125,977)	(2,721)
Acquisitions of reacquired franchise rights		(2,377)
Net cash used in investing activities	(151,535)	(27,686)
Cash Flows from Financing Activities:
Proceeds from issuance of stock upon exercise of stock options and warrants	236	1,358
Proceeds from issuance of stock to employee stock purchase plan	2,731	3,012
Tax benefit from stock option exercises	(334)	2,192
Non-controlling interest distribution	(198)	(185)
Principal payments of long-term obligations	(19,576)	(22,583)
Net cash used in financing activities	(17,141)	(16,206)
Net (decrease) increase in cash and cash equivalents	(92,163)	81,542
Cash and cash equivalents at beginning of period	120,295	34,485
Cash and cash equivalents at end of period	28,132	116,027
Supplemental Disclosures of Cash Flow Information:
Cash paid for interest	3,656	4,266
Cash paid for income taxes, net of refunds received	6,273	31,870
Supplemental Disclosures of Non-Cash Financing and Investing Activities:
Notes payable issued for acquisitions		750
Notes payable issued for software licenses		$ 10,801