Derivatives and Hedging Activities (Details 4) (USD $) In Millions, unless otherwise specified	Sep. 30, 2011 Year Loan Contract	Dec. 31, 2010 Year	Sep. 30, 2010 Year
Largest exposure to an individual counterparty
Collateral posted by this counterparty	$ 901
Derivative liability with this counterparty	907
Fair value of derivative assets
Derivative assets before collateral	1,451	1,337	1,796
Less: Related collateral	511	331	538
Derivative Assets, Total	940	1,006	1,258
Fair value of credit derivatives purchased and sold
Credit derivatives purchased	17	(3)	11
Credit derivatives sold	(14)	11	0
Credit derivative, net	3	8	11
Credit derivatives sold and held
Credit derivative, notional amount	1,269	1,359	1,480
Credit derivative, average term (years)	0	0	0
Credit derivative payment/performance risk percentage	0.00%	0.00%	0.00%
Credit Derivative Payment Performance Risk		Low	Low
Credit risk contingent feature
Additional Collateral, Aggregate Fair Value	196
Credit Concentration Risk [Member]
Largest exposure to an individual counterparty
Largest gross exposure (derivative asset) to an individual counterparty	205	168	241
Collateral posted by this counterparty	54	25	46
Derivative liability with this counterparty	250	275	338
Collateral pledged to this counterparty	114	141	143
Net exposure after netting adjustments and collateral	14	9	2
One Rating Downgrade [Member] | Moody's, A2 Rating [Member]
Credit risk contingent feature
Additional Collateral, Aggregate Fair Value	11	16	29
One Rating Downgrade [Member] | Standard & Poor's, A- Rating [Member]
Credit risk contingent feature
Additional Collateral, Aggregate Fair Value	11	16	19
Two Rating Downgrade [Member] | Moody's, A2 Rating [Member]
Credit risk contingent feature
Additional Collateral, Aggregate Fair Value	16	27	48
Two Rating Downgrade [Member] | Standard & Poor's, A- Rating [Member]
Credit risk contingent feature
Additional Collateral, Aggregate Fair Value	16	27	27
Three Rating Downgrade [Member] | Moody's, A2 Rating [Member]
Credit risk contingent feature
Additional Collateral, Aggregate Fair Value	16	32	55
Three Rating Downgrade [Member] | Standard & Poor's, A- Rating [Member]
Credit risk contingent feature
Additional Collateral, Aggregate Fair Value	16	32	32
Interest rate [Member]
Fair value of derivative assets
Derivative assets before collateral	1,298	1,134	1,549
Foreign exchange [Member]
Fair value of derivative assets
Derivative assets before collateral	71	104	157
Energy and commodity [Member]
Fair value of derivative assets
Derivative assets before collateral	65	84	72
Credit [Member]
Fair value of derivative assets
Derivative assets before collateral	15	14	17
Equity [Member]
Fair value of derivative assets
Derivative assets before collateral	2	1	1
Single name credit default swaps [Member]
Fair value of credit derivatives purchased and sold
Credit derivatives purchased	9	(8)	6
Credit derivatives sold	(5)	9	2
Credit derivative, net	4	1	8
Credit derivatives sold and held
Credit derivative, notional amount	903	942	1,033
Credit derivative, average term (years)	2.37	2.42	2.43
Credit derivative payment/performance risk percentage	3.89%	3.93%	2.85%
Traded credit default swap indices [Member]
Fair value of credit derivatives purchased and sold
Credit derivatives purchased	6	0	1
Credit derivatives sold	(8)	2	(1)
Credit derivative, net	(2)	2	0
Credit derivatives sold and held
Credit derivative, notional amount	346	369	399
Credit derivative, average term (years)	3.45	3.86	4.00
Credit derivative payment/performance risk percentage	4.04%	6.68%	6.78%
Others [Member]
Fair value of credit derivatives purchased and sold
Credit derivatives purchased	2	5	4
Credit derivatives sold	(1)	0	(1)
Credit derivative, net	1	5	3
Credit derivatives sold and held
Credit derivative, notional amount	$ 20	$ 48	$ 48
Credit derivative, average term (years)	5.55	2.00	2.90
Credit derivative payment/performance risk percentage	10.82%