Commercial Paper and Long-Term Debt Balance Sheet Location of Fair Value Derivatives (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Derivatives, Fair Value [Line Items]
Interest Rate Derivative Liabilities, at Fair Value	$ 163,000,000
Interest rate swap assets		14,000,000
Interest Rate Swap [Member]
Derivatives, Fair Value [Line Items]
Derivative, Notional Amount	6,200,000,000	2,800,000,000
Interest Rate Swap [Member] | Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Interest Rate Derivative Liabilities, at Fair Value	163,000,000	11,000,000
Interest Rate Swap [Member] | Other Assets [Member]
Derivatives, Fair Value [Line Items]
Interest rate swap assets		$ 14,000,000