Derivatives and Hedging Activities (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Other Assets [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives assets	$ 1,089	$ 1,516
Cash collateral netting	(681)	(587)
Derivative asset and liability netting	(18)	(14)
Total derivatives, net	390	915
Other Assets [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives assets	964	1,356
Other Assets [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives assets	125	160
Other Assets [Member] | Interest rate contracts [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives assets	0	1
Other Assets [Member] | Foreign exchange contracts [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives assets	125	159
Other Assets [Member] | Equity-linked contract [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives assets	0	0
Other Assets [Member] | Fair Value Hedging [Member] | Interest rate contracts [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives assets	938	999
Other Assets [Member] | Fair Value Hedging [Member] | Total Return Swap [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives assets	0	13
Other Assets [Member] | Cash flow hedges [Member] | Interest rate contracts [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives assets	0	0
Other Assets [Member] | Net investment hedges [Member] | Foreign exchange contracts [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives assets	26	344
Other Liabilities [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives liabilities	403	108
Cash collateral netting	(16)	0
Derivative asset and liability netting	(18)	(14)
Total derivatives, net	369	94
Other Liabilities [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives liabilities	296	55
Other Liabilities [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives liabilities	107	53
Other Liabilities [Member] | Interest rate contracts [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives liabilities	1	0
Other Liabilities [Member] | Foreign exchange contracts [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives liabilities	104	50
Other Liabilities [Member] | Equity-linked contract [Member] | Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives liabilities	2	3
Other Liabilities [Member] | Fair Value Hedging [Member] | Interest rate contracts [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives liabilities	0	0
Other Liabilities [Member] | Fair Value Hedging [Member] | Total Return Swap [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives liabilities	23	0
Other Liabilities [Member] | Cash flow hedges [Member] | Interest rate contracts [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives liabilities	0	1
Other Liabilities [Member] | Net investment hedges [Member] | Foreign exchange contracts [Member] | Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Total fair value of derivatives liabilities	$ 273	$ 54