Guarantor (Cash Flow Statements) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Cash flows from operating activities:
Net cash flows provided by operating activities	$ 69,819	$ 73,865
Cash flows from investing activities:
Acquisition of interests in surgery centers and related transactions	(5,038)	(252)
Acquisition of property and equipment	(7,038)	(6,110)
Proceeds from sale of interests in surgery centers	1,111	0
Other	(418)	0
Net cash flows used in investing activities	(11,383)	(6,362)
Cash flows from financing activities:
Proceeds from long-term borrowings	31,945	30,870
Repayment on long-term borrowings	(50,853)	(48,211)
Distributions to noncontrolling interests	(43,194)	(43,914)
Net cash flows provided by (used in) financing activities	(62,160)	(71,488)
Net increase (decrease) in cash and cash equivalents	(3,724)	(3,985)
Cash and cash equivalents, beginning of period	50,840	46,398
Cash and cash equivalents, end of period	47,116	42,413
Consolidation, Eliminations [Member]
Cash flows from operating activities:
Net cash flows provided by operating activities	(93,016)	(99,063)
Cash flows from investing activities:
Acquisition of interests in surgery centers and related transactions	44	(10)
Acquisition of property and equipment	0	0
Proceeds from sale of interests in surgery centers	0	0
Other	0	0
Net cash flows used in investing activities	44	(10)
Cash flows from financing activities:
Proceeds from long-term borrowings	0	0
Repayment on long-term borrowings	0	0
Distributions to noncontrolling interests	93,016	99,063
Capital contributions	0
Changes In Intercompany Balances	0	0
Other financing activities, net	(44)	10
Net cash flows provided by (used in) financing activities	92,972	99,073
Net increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents, beginning of period	0	0
Cash and cash equivalents, end of period	0	0
Parent Company [Member]
Cash flows from operating activities:
Net cash flows provided by operating activities	18,482	23,940
Cash flows from investing activities:
Acquisition of interests in surgery centers and related transactions	0	0
Acquisition of property and equipment	(1,237)	(853)
Proceeds from sale of interests in surgery centers	0	0
Other	(629)	0
Net cash flows used in investing activities	(1,866)	(853)
Cash flows from financing activities:
Proceeds from long-term borrowings	30,000	29,700
Repayment on long-term borrowings	(47,679)	(45,024)
Distributions to noncontrolling interests	0	0
Capital contributions	0
Changes In Intercompany Balances	556	533
Other financing activities, net	(641)	(10,792)
Net cash flows provided by (used in) financing activities	(17,764)	(25,583)
Net increase (decrease) in cash and cash equivalents	(1,148)	(2,496)
Cash and cash equivalents, beginning of period	6,710	7,259
Cash and cash equivalents, end of period	5,562	4,763
Guarantor Subsidiaries [Member]
Cash flows from operating activities:
Net cash flows provided by operating activities	48,096	49,577
Cash flows from investing activities:
Acquisition of interests in surgery centers and related transactions	(5,082)	(242)
Acquisition of property and equipment	0	0
Proceeds from sale of interests in surgery centers	1,111	0
Other	211	0
Net cash flows used in investing activities	(3,760)	(242)
Cash flows from financing activities:
Proceeds from long-term borrowings	0	0
Repayment on long-term borrowings	0	0
Distributions to noncontrolling interests	(44,920)	(49,486)
Capital contributions	0
Changes In Intercompany Balances	0	0
Other financing activities, net	584	151
Net cash flows provided by (used in) financing activities	(44,336)	(49,335)
Net increase (decrease) in cash and cash equivalents	0	0
Cash and cash equivalents, beginning of period	0	0
Cash and cash equivalents, end of period	0	0
Non-Guarantor Subsidiaries [Member]
Cash flows from operating activities:
Net cash flows provided by operating activities	96,257	99,411
Cash flows from investing activities:
Acquisition of interests in surgery centers and related transactions	0	0
Acquisition of property and equipment	(5,801)	(5,257)
Proceeds from sale of interests in surgery centers	0	0
Other	0	0
Net cash flows used in investing activities	(5,801)	(5,257)
Cash flows from financing activities:
Proceeds from long-term borrowings	1,945	1,170
Repayment on long-term borrowings	(3,174)	(3,187)
Distributions to noncontrolling interests	(91,290)	(93,491)
Capital contributions	0
Changes In Intercompany Balances	(556)	(533)
Other financing activities, net	43	398
Net cash flows provided by (used in) financing activities	(93,032)	(95,643)
Net increase (decrease) in cash and cash equivalents	(2,576)	(1,489)
Cash and cash equivalents, beginning of period	44,130	39,139
Cash and cash equivalents, end of period	41,554	37,650
Consolidated Entities [Member]
Cash flows from financing activities:
Changes In Intercompany Balances	0	0
Other financing activities, net	$ (58)	$ (10,233)