Derivatives And Risk Management (Fair Values Of Derivatives) (Details) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Derivative assets, fair value	$ 10	$ 12
Derivative liabilities, fair value	34	37
Interest Rate Contracts [Member] | Derivatives Designated As Hedging Instruments [Member]
Derivative assets, fair value	1	6
Derivative liabilities, fair value	6	3
Interest Rate Contracts [Member] | Derivatives Designated As Hedging Instruments [Member] | Miscellaneous Receivables [Member]
Derivative assets, fair value	0	0
Interest Rate Contracts [Member] | Derivatives Designated As Hedging Instruments [Member] | Accrued Liabilities [Member]
Derivative liabilities, fair value	6	3
Interest Rate Contracts [Member] | Derivatives Designated As Hedging Instruments [Member] | Other Assets [Member]
Derivative assets, fair value	1	6
Interest Rate Contracts [Member] | Derivatives Designated As Hedging Instruments [Member] | Other Liabilities [Member]
Derivative liabilities, fair value	0	0
Interest Rate Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member]
Derivative assets, fair value	7	5
Derivative liabilities, fair value	27	33
Interest Rate Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Miscellaneous Receivables [Member]
Derivative assets, fair value	0	0
Interest Rate Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Accrued Liabilities [Member]
Derivative liabilities, fair value	11	13
Interest Rate Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Other Assets [Member]
Derivative assets, fair value	7	5
Interest Rate Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Other Liabilities [Member]
Derivative liabilities, fair value	16	20
Foreign Exchange Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Miscellaneous Receivables [Member]
Derivative assets, fair value	2	1
Foreign Exchange Contracts [Member] | Derivatives Not Designated As Hedging Instruments [Member] | Accrued Liabilities [Member]
Derivative liabilities, fair value	$ 1	$ 1