Derivative Financial Instruments and Hedging Activities (Details 2) (USD $) In Millions	Jun. 30, 2011	Dec. 31, 2010
Assets:
Derivative assets financial and hedging instruments, fair value	$ 50	$ 47
Liabilities:
Derivative liabilities financial and hedging instruments, fair value	(14)	(12)
Interest Rate Swap [Member] | Other Assets [Member] | Cash Flow Hedging [Member]
Assets:
Derivative assets financial and hedging instruments, fair value	15	17
Interest Rate Swap [Member] | Other Assets [Member] | Fair Value Hedging [Member]
Assets:
Derivative assets financial and hedging instruments, fair value	22	14
Interest Rate Swap [Member] | Other Liabilities [Member] | Cash Flow Hedging [Member]
Liabilities:
Derivative liabilities financial and hedging instruments, fair value	(2)	(2)
Forward Contracts [Member] | Other Assets [Member]
Assets:
Derivative assets financial and hedging instruments, fair value	13	16
Forward Contracts [Member] | Other Liabilities [Member]
Liabilities:
Derivative liabilities financial and hedging instruments, fair value	$ (12)	$ (10)