Investments in Unconsolidated Affiliates (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($) entity equity_method_investment center	Sep. 30, 2014 USD ($) entity center	Dec. 31, 2014 USD ($)
Schedule of Equity Method Investments [Line Items]
Investments in unconsolidated affiliates	$ 112,877		$ 112,877		$ 75,475
Equity in earnings of unconsolidated affiliates	4,935	$ 2,158	11,575	$ 3,461
Gain on deconsolidation	$ 9,112	$ 0	5,854	3,411
Joint Venture [Member]
Schedule of Equity Method Investments [Line Items]
Increase in Equity Method Investments			$ 26,900	$ 7,000
Ambulatory Services [Member] | Controlling Interest [Member] | Joint Venture [Member]
Schedule of Equity Method Investments [Line Items]
Number consolidated entities contributed to joint venture | center			3	4
Ambulatory Services [Member] | Noncontrolling Interest In Centers [Member] | Joint Venture [Member]
Schedule of Equity Method Investments [Line Items]
Number of separate equity method investments			2	4
Number of joint venture entities acquired | entity			1	1
Ambulatory Services [Member] | Noncontrolling Interest In Surgical Hospital [Member] | Joint Venture [Member]
Schedule of Equity Method Investments [Line Items]
Number of joint venture entities acquired | entity			1
Physician Services [Member] | Controlling Interest [Member] | Joint Venture [Member]
Schedule of Equity Method Investments [Line Items]
Number consolidated entities contributed to joint venture | center			2
Deconsolidation [Member] | Ambulatory Services [Member]
Schedule of Equity Method Investments [Line Items]
Proceeds from deconsolidation				$ 1,200