Goodwill And Intangible Assets (Narrative) (Details) $ in Thousands		3 Months Ended			6 Months Ended
		Jun. 30, 2015 USD ($)		Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) physician_practice center		Jun. 30, 2014 USD ($) center	Dec. 31, 2014 USD ($)
Segment Reporting Information [Line Items]
Goodwill		$ 3,586,021			$ 3,586,021			$ 3,381,149
Increase in goodwill					208,196
Goodwill deductible for tax purposes		107,600		$ 25,100	107,600		$ 25,100
Amortization of Intangible Assets		16,800		600	33,400		1,100
Estimated amortization of intangible assets, remainder of 2014		34,100			34,100
Estimated amortization of intangible assets, 2015		67,600			67,600
Estimated amortization of intangible assets, 2016		66,300			66,300
Estimated amortization of intangible assets, 2017		65,200			65,200
Estimated amortization of intangible assets, 2018		62,500			62,500
Estimated amortization of intangible assets, 2019		59,600			59,600
Estimated amortization of intangible assets, 2020 and thereafter		689,100			$ 689,100
Weighted average amortization period					17 years 288 days
Ambulatory Services [Member]
Segment Reporting Information [Line Items]
Goodwill		2,000,000			$ 2,000,000
Increase in goodwill					144,800
Physician Services [Member]
Segment Reporting Information [Line Items]
Goodwill		1,600,000			1,600,000
Increase in goodwill					60,000
Series of Individually Immaterial Business Acquisitions [Member]
Segment Reporting Information [Line Items]
Goodwill		220,952	[1]	44,319	220,952	[1]	44,319
Intangible assets		32,313	[1]	$ 0	$ 32,313	[1]	$ 0
Series of Individually Immaterial Business Acquisitions [Member] | Physician Services [Member]
Segment Reporting Information [Line Items]
Number of business acquisitions | physician_practice					4
Sheridan Healthcare [Member]
Segment Reporting Information [Line Items]
Post acquisition adjustment to goodwill	[1]				$ 12,900
Controlling Interest [Member] | Ambulatory Services [Member]
Segment Reporting Information [Line Items]
Number of business acquisitions | center					4		2
Controlling Interest [Member] | Joint Venture [Member] | Ambulatory Services [Member]
Segment Reporting Information [Line Items]
Number consolidated entities contributed to joint venture | center					1		4
Controlling Interest [Member] | Joint Venture [Member] | Physician Services [Member]
Segment Reporting Information [Line Items]
Number consolidated entities contributed to joint venture | center					1
Customer relationships with hospitals [Member]
Segment Reporting Information [Line Items]
Amount estimated to be amortized over weighted average period		$ 29,800			$ 29,800
Weighted average period of amortization		20 years

[1] Represents the preliminary allocation of fair value of acquired assets and liabilities associated with these acquisitions at June 30, 2015.