Financial Information for the Company and Its Subsidiaries (Cash Flow Statements) (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows from operating activities:
Net cash flows provided by (used in) operating activities	$ 427,202	$ 276,051
Cash flows from investing activities:
Acquisitions and related expenses	(233,490)	(2,138,648)
Acquisition of property and equipment	(47,006)	(23,109)
Proceeds from sale of interests in surgery centers	0	4,969
Purchases of marketable securities	(1,743)	(3,486)
Maturities of marketable securities	4,233	0
Other	(3,974)	2,082
Net cash flows used in investing activities	(281,980)	(2,158,192)
Cash flows from financing activities:
Proceeds from long-term borrowings	10,197	2,046,399
Repayment on long-term borrowings	(15,737)	(403,043)
Distributions to owners, including noncontrolling interests	(158,144)	(139,443)
Capital contributions	0	0
Proceeds from preferred stock offering	0	172,500
Cash dividends for preferred shares	(6,792)	(2,239)
Proceeds from common stock offering	0	439,875
Payments of equity issuance costs	0	(24,366)
Financing cost incurred	(294)	(65,673)
Changes in intercompany balances with affiliates, net	0	0
Other, net	4,891	1,372
Net cash flows provided by (used in) financing activities	(165,879)	2,025,382
Net increase (decrease) in cash and cash equivalents	(20,657)	143,241
Cash and cash equivalents, beginning of period	208,079	50,840
Cash and cash equivalents, end of period	187,422	194,081
Consolidation, Eliminations [Member]
Cash flows from operating activities:
Net cash flows provided by (used in) operating activities	(233,773)	(361,171)
Cash flows from investing activities:
Acquisitions and related expenses	31,774	2,149,974
Acquisition of property and equipment	0	0
Proceeds from sale of interests in surgery centers		0
Purchases of marketable securities	0	0
Maturities of marketable securities	0
Other	0	0
Net cash flows used in investing activities	31,774	2,149,974
Cash flows from financing activities:
Proceeds from long-term borrowings	0	0
Repayment on long-term borrowings	0	0
Distributions to owners, including noncontrolling interests	233,773	361,171
Capital contributions	(29,157)	(2,147,585)
Proceeds from preferred stock offering		0
Cash dividends for preferred shares	0	0
Proceeds from common stock offering		0
Payments of equity issuance costs		0
Financing cost incurred	0	0
Changes in intercompany balances with affiliates, net	0	0
Other, net	(2,617)	(2,389)
Net cash flows provided by (used in) financing activities	201,999	(1,788,803)
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 (used in) operating activities	(20,702)	103,091
Cash flows from investing activities:
Acquisitions and related expenses	(29,157)	(2,147,585)
Acquisition of property and equipment	(5,659)	(3,653)
Proceeds from sale of interests in surgery centers		0
Purchases of marketable securities	0	0
Maturities of marketable securities	0
Other	0	(2,555)
Net cash flows used in investing activities	(34,816)	(2,153,793)
Cash flows from financing activities:
Proceeds from long-term borrowings	0	2,040,000
Repayment on long-term borrowings	(6,525)	(394,318)
Distributions to owners, including noncontrolling interests	0	0
Capital contributions	0	0
Proceeds from preferred stock offering		172,500
Cash dividends for preferred shares	(6,792)	(2,239)
Proceeds from common stock offering		439,875
Payments of equity issuance costs		(24,366)
Financing cost incurred	(294)	(65,673)
Changes in intercompany balances with affiliates, net	524	731
Other, net	2,984	1,311
Net cash flows provided by (used in) financing activities	(10,103)	2,167,821
Net increase (decrease) in cash and cash equivalents	(65,621)	117,119
Cash and cash equivalents, beginning of period	134,351	6,710
Cash and cash equivalents, end of period	68,730	123,829
Guarantor Subsidiaries [Member]
Cash flows from operating activities:
Net cash flows provided by (used in) operating activities	313,286	225,098
Cash flows from investing activities:
Acquisitions and related expenses	(236,107)	(2,142,611)
Acquisition of property and equipment	(15,418)	(2,337)
Proceeds from sale of interests in surgery centers		4,969
Purchases of marketable securities	0	0
Maturities of marketable securities	0
Other	(779)	(648)
Net cash flows used in investing activities	(252,304)	(2,140,627)
Cash flows from financing activities:
Proceeds from long-term borrowings	0	0
Repayment on long-term borrowings	0	0
Distributions to owners, including noncontrolling interests	(59,616)	(206,580)
Capital contributions	29,157	2,147,585
Proceeds from preferred stock offering		0
Cash dividends for preferred shares	0	0
Proceeds from common stock offering		0
Payments of equity issuance costs		0
Financing cost incurred	0	0
Changes in intercompany balances with affiliates, net	0	0
Other, net	2,653	(206)
Net cash flows provided by (used in) financing activities	(27,806)	1,940,799
Net increase (decrease) in cash and cash equivalents	33,176	25,270
Cash and cash equivalents, beginning of period	23,471	0
Cash and cash equivalents, end of period	56,647	25,270
Non-Guarantor Subsidiaries [Member]
Cash flows from operating activities:
Net cash flows provided by (used in) operating activities	368,391	309,033
Cash flows from investing activities:
Acquisitions and related expenses	0	1,574
Acquisition of property and equipment	(25,929)	(17,119)
Proceeds from sale of interests in surgery centers		0
Purchases of marketable securities	(1,743)	(3,486)
Maturities of marketable securities	4,233
Other	(3,195)	5,285
Net cash flows used in investing activities	(26,634)	(13,746)
Cash flows from financing activities:
Proceeds from long-term borrowings	10,197	6,399
Repayment on long-term borrowings	(9,212)	(8,725)
Distributions to owners, including noncontrolling interests	(332,301)	(294,034)
Capital contributions	0	0
Proceeds from preferred stock offering		0
Cash dividends for preferred shares	0	0
Proceeds from common stock offering		0
Payments of equity issuance costs		0
Financing cost incurred	0	0
Changes in intercompany balances with affiliates, net	(524)	(731)
Other, net	1,871	2,656
Net cash flows provided by (used in) financing activities	(329,969)	(294,435)
Net increase (decrease) in cash and cash equivalents	11,788	852
Cash and cash equivalents, beginning of period	50,257	44,130
Cash and cash equivalents, end of period	$ 62,045	$ 44,982