Derivatives and Hedging Activities (Details 4) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Largest exposure to an individual counterparty
Collateral posted by this counterparty	$ 879
Derivative liability with this counterparty	889
Fair value of derivative assets
Derivative assets before collateral	1,431	1,337
Less: Related collateral	486	331
Derivative Assets, Total	945	1,006
Fair value of credit derivatives purchased and sold
Credit derivatives purchased	10	(3)
Credit derivatives sold	(8)	11
Credit derivative, net	2	8
Credit derivatives sold and held
Credit derivative, notional amount	1,239	1,359
Credit derivative payment performance risk		Low
Credit risk contingent feature
Additional collateral aggregate fair value	206
Single name credit default swaps [Member]
Fair value of credit derivatives purchased and sold
Credit derivatives purchased	3	(8)
Credit derivatives sold	(1)	9
Credit derivative, net	2	1
Credit derivatives sold and held
Credit derivative, notional amount	878	942
Credit derivative, average term (years)	2.18	2.42
Credit derivative payment/performance risk percentage	4.98%	3.93%
Traded credit default swap indices [Member]
Fair value of credit derivatives purchased and sold
Credit derivatives purchased	6	0
Credit derivatives sold	(6)	2
Credit derivative, net	0	2
Credit derivatives sold and held
Credit derivative, notional amount	343	369
Credit derivative, average term (years)	3.20	3.86
Credit derivative payment/performance risk percentage	4.58%	6.68%
Others [Member]
Fair value of credit derivatives purchased and sold
Credit derivatives purchased	1	5
Credit derivatives sold	(1)	0
Credit derivative, net	0	5
Credit derivatives sold and held
Credit derivative, notional amount	18	48
Credit derivative, average term (years)	5.74	2.00
Credit derivative payment/performance risk percentage	10.89%
Interest rate [Member]
Fair value of derivative assets
Derivative assets before collateral	1,257	1,134
Foreign exchange [Member]
Fair value of derivative assets
Derivative assets before collateral	64	104
Energy and commodity [Member]
Fair value of derivative assets
Derivative assets before collateral	96	84
Credit [Member]
Fair value of derivative assets
Derivative assets before collateral	12	14
Equity [Member]
Fair value of derivative assets
Derivative assets before collateral	2	1
One Rating Downgrade [Member] | Standard & Poor's, A- Rating [Member]
Credit risk contingent feature
Additional collateral aggregate fair value	11	16
One Rating Downgrade [Member] | Moody's, A3 Rating [Member]
Credit risk contingent feature
Additional collateral aggregate fair value	11	16
Two Rating Downgrade [Member] | Standard & Poor's, A- Rating [Member]
Credit risk contingent feature
Additional collateral aggregate fair value	16	27
Two Rating Downgrade [Member] | Moody's, A3 Rating [Member]
Credit risk contingent feature
Additional collateral aggregate fair value	16	27
Three Rating Downgrade [Member] | Standard & Poor's, A- Rating [Member]
Credit risk contingent feature
Additional collateral aggregate fair value	16	32
Three Rating Downgrade [Member] | Moody's, A3 Rating [Member]
Credit risk contingent feature
Additional collateral aggregate fair value	16	32
Credit Concentration Risk [Member]
Largest exposure to an individual counterparty
Largest gross exposure (derivative asset) to an individual counterparty	194	168
Collateral posted by this counterparty	64	25
Derivative liability with this counterparty	250	275
Collateral pledged to this counterparty	127	141
Net exposure after netting adjustments and collateral	$ 7	$ 9