Derivatives and Hedging Activities (Details 4) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011
Fair value of derivative assets
Derivative assets before collateral	$ 1,280	$ 1,431	$ 1,269
Less: Related collateral	450	486	264
Derivative Assets, Total	830	945	1,005
Fair value of credit derivatives purchased and sold
Credit derivatives purchased	(11)	10	(7)
Credit derivatives sold	12	(8)	13
Credit derivative, net	1	2	6
Credit derivatives sold and held
Credit derivative, notional amount	1,486	1,239	1,340
Credit derivative payment/performance risk percentage			4.28%
Credit risk contingent feature
Additional collateral aggregate fair value	199
Single name credit default swaps [Member]
Fair value of credit derivatives purchased and sold
Credit derivatives purchased	(12)	3	(11)
Credit derivatives sold	7	(1)	11
Credit derivative, net	(5)	2
Credit derivatives sold and held
Credit derivative, notional amount	973	878	955
Credit derivative, average term (years)	2.26	2.18	2.30
Credit derivative payment/performance risk percentage	4.53%	4.98%	3.40%
Traded credit default swap indices [Member]
Fair value of credit derivatives purchased and sold
Credit derivatives purchased		6
Credit derivatives sold	6	(6)	2
Credit derivative, net	6		2
Credit derivatives sold and held
Credit derivative, notional amount	497	343	369
Credit derivative, average term (years)	2.78	3.20	3.37
Credit derivative payment/performance risk percentage	2.09%	4.58%	3.76%
Others [Member]
Fair value of credit derivatives purchased and sold
Credit derivatives purchased	1	1	4
Credit derivatives sold	(1)	(1)
Credit derivative, net			4
Credit derivatives sold and held
Credit derivative, notional amount	16	18	16
Credit derivative, average term (years)	5.77	5.74	1.45
Credit derivative payment/performance risk percentage	10.29%	10.89%
Interest rate [Member]
Fair value of derivative assets
Derivative assets before collateral	1,117	1,257	939
Foreign exchange [Member]
Fair value of derivative assets
Derivative assets before collateral	34	64	116
Energy and commodity [Member]
Fair value of derivative assets
Derivative assets before collateral	121	96	200
Credit [Member]
Fair value of derivative assets
Derivative assets before collateral	6	12	11
Equity [Member]
Fair value of derivative assets
Derivative assets before collateral	2	2	3
One Rating Downgrade [Member] | Standard & Poor's, A- Rating [Member]
Credit risk contingent feature
Additional collateral aggregate fair value	6	11	18
One Rating Downgrade [Member] | Moody's, A3 Rating [Member]
Credit risk contingent feature
Additional collateral aggregate fair value	6	11	18
Two Rating Downgrade [Member] | Standard & Poor's, A- Rating [Member]
Credit risk contingent feature
Additional collateral aggregate fair value	11	16	28
Two Rating Downgrade [Member] | Moody's, A3 Rating [Member]
Credit risk contingent feature
Additional collateral aggregate fair value	11	16	28
Three Rating Downgrade [Member] | Standard & Poor's, A- Rating [Member]
Credit risk contingent feature
Additional collateral aggregate fair value	11	16	33
Three Rating Downgrade [Member] | Moody's, A3 Rating [Member]
Credit risk contingent feature
Additional collateral aggregate fair value	11	16	33
Credit Concentration Risk [Member]
Largest exposure to an individual counterparty
Largest gross exposure (derivative asset) to an individual counterparty	179	194	138
Collateral posted by this counterparty	57	64	19
Derivative liability with this counterparty	233	250	276
Collateral pledged to this counterparty	119	127	160
Net exposure after netting adjustments and collateral	$ 7	$ 7	$ 3