Acquisitions (Narrative) (Details) $ in Thousands			3 Months Ended		9 Months Ended
	Jul. 16, 2014 USD ($) shares	Jul. 02, 2014 shares	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($) physician_practice center	Sep. 30, 2014 USD ($) center	Dec. 31, 2014 USD ($)	Jul. 15, 2014 USD ($)
Business Acquisition [Line Items]
Transaction costs			$ 2,107	$ 25,102	$ 5,560	$ 28,681
Acquisitions and related expenses, net					233,490	2,138,648
Net change in fair value of contingent consideration			1,928	$ 0	8,338	0
Sheridan Healthcare [Member]
Business Acquisition [Line Items]
Cash paid to acquire business	$ 2,100,000
Value of common stock issued for acquisition	$ 272,000
Post acquisition adjustment to goodwill					8,700
Common Stock [Member]
Business Acquisition [Line Items]
Issuance of stock (in shares) | shares		9,775,000
Common Stock [Member] | Sheridan Healthcare [Member]
Business Acquisition [Line Items]
Shares of common stock issued for acquisition | shares	5,713,909
Mandatory Convertible Preferred Stock [Member]
Business Acquisition [Line Items]
Issuance of stock (in shares) | shares		1,725,000
Senior Secured Credit Facility - Term Loan [Member]
Business Acquisition [Line Items]
Maximum borrowing capacity	$ 870,000
Revolving Credit Facility [Member]
Business Acquisition [Line Items]
Maximum borrowing capacity	300,000							$ 475,000
Senior Notes [Member] | 2022 Senior Unsecured Notes [Member]
Business Acquisition [Line Items]
Face amount	$ 1,100,000
Interest rate	5.625%
Ambulatory Services [Member]
Business Acquisition [Line Items]
Acquisitions and related expenses, net					$ 112,900	$ 24,400
Ambulatory Services [Member] | Controlling Interest [Member]
Business Acquisition [Line Items]
Number of business acquisitions | center					5	4
Sheridan Healthcare [Member] | Controlling Interest [Member]
Business Acquisition [Line Items]
Number of business acquisitions | center						2
Physician Services [Member]
Business Acquisition [Line Items]
Net change in fair value of contingent consideration			1,928		$ 8,338
Physician Services [Member] | Series of Individually Immaterial Business Acquisitions [Member]
Business Acquisition [Line Items]
Cash paid to acquire business			120,600
Business Combination, Contingent Consideration, Liability			33,700		$ 33,700		$ 20,700
Number of business acquisitions | physician_practice					6
Contingent consideration arrangements, low			32,000		$ 32,000
Contingent consideration arrangements, high			$ 35,000		$ 35,000