Goodwill And Intangible Assets (Narrative) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2016 USD ($) physician_practice	Mar. 31, 2015 USD ($) physician_practice	Dec. 31, 2015 USD ($)
Segment Reporting Information [Line Items]
Goodwill	$ 3,967,902		$ 3,970,210
Decrease in goodwill	(2,308)
Goodwill deductible for tax purposes	1,100	$ 49,400
Amortization of Intangible Assets	20,400	$ 14,500
Estimated amortization of intangible assets, remainder of 2016	62,100
Estimated amortization of intangible assets, 2017	81,600
Estimated amortization of intangible assets, 2018	80,400
Estimated amortization of intangible assets, 2019	77,700
Estimated amortization of intangible assets, 2020	75,400
Estimated amortization of intangible assets, 2021	71,600
Estimated amortization of intangible assets, 2022 and thereafter	$ 894,500
Weighted average amortization period	18 years
Ambulatory Services [Member]
Segment Reporting Information [Line Items]
Goodwill	$ 2,000,000
Physician Services [Member]
Segment Reporting Information [Line Items]
Goodwill	2,000,000
Decrease in goodwill	$ (2,200)
Physician Services [Member] | Series of Individually Immaterial Business Acquisitions [Member]
Segment Reporting Information [Line Items]
Number of business acquisitions | physician_practice	1	3