Segment Reporting (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								6 Months Ended			12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014 segment		Jul. 15, 2014 segment	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Segment Reporting [Abstract]
Number of reportable segments									2		1
Segment Reporting Information [Line Items]
Net revenues	$ 581,811	$ 502,350	$ 278,227	$ 259,561	$ 279,095	$ 262,240	$ 262,497	$ 253,364				$ 1,621,949		$ 1,057,196		$ 899,245
Adjusted EBITDA												304,482		187,972		154,527
Earnings from continuing operations attributable to noncontrolling interests												190,809		183,484		155,661
Interest expense, net												(83,285)		(29,525)		(16,950)
Depreciation and amortization												(60,344)		(32,400)		(29,255)
Share-based compensation												(10,104)		(8,321)		(6,692)
Transaction costs		(25,100)										(33,890)		(300)		(700)
Debt extinguishment costs		(16,900)										(16,887)		0		0
Gain on deconsolidation												3,411		2,237		0
Earnings from continuing operations before income taxes	101,535	39,141	80,487	73,029	80,363	72,615	77,100	73,069				294,192		303,147		256,591
Acquisition and Capital Expenditures												110,065		102,450		306,252
Assets	5,523,524				2,177,944				5,523,524			5,523,524		2,177,944
Ambulatory Services [Member]
Segment Reporting Information [Line Items]
Net revenues												1,109,935		1,057,196		899,245
Adjusted EBITDA												197,377		187,972		154,527
Acquisition and Capital Expenditures												81,156	[1]	102,450	[1]	306,252	[1]
Assets	2,528,525				2,177,944				2,528,525			2,528,525		2,177,944
Physician Services [Member]
Segment Reporting Information [Line Items]
Net revenues									512,014	[2]		512,014		0		0
Adjusted EBITDA												107,105		0		0
Acquisition and Capital Expenditures												28,909		0		0
Assets	$ 2,994,999				$ 0				$ 2,994,999			$ 2,994,999		$ 0

[1] Excludes the purchase price to acquire Sheridan.

[2] Net revenue by payor is for the period July 16, 2014, the date of the acquisition of Sheridan, through December 31, 2014. As such, historical amounts are not included.