Derivatives and Hedging Activities (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Cash flow hedges [Member] | Interest Expense [Member] | Interest rate contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount reclassified from AOCI into income	$ 0	$ (8)
Cash flow hedges [Member] | Other Expense [Member] | Interest rate contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Net hedge ineffectiveness	0	0
Net investment hedges [Member] | Other Expense [Member] | Foreign exchange contracts [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount reclassified from AOCI into income	0	0
Net hedge ineffectiveness	$ 0	$ (3)