Equity Investments (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Schedule of Equity Method Investments [Line Items]
Equity Method Investments	$ 441		$ 441		$ 422
Equity in earnings of unconsolidated affiliates	$ 11	$ 9	$ 22	$ 24
Four Hospitals in Las Vegas, Nevada [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	27.50%		27.50%
One Hospital in Las Vegas, Nevada [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	26.10%		26.10%
Three Hospitals in Macon Georgia, [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	38.00%		38.00%
HealthTrust [Member]
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Ownership Percentage	25.90%		25.90%