Derivatives and Hedging Activities - Fair Values, Volume of Activity and Gain (Loss) Information Related to Derivative Instruments (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
Derivatives, Fair Value [Line Items]
Notional Amount	$ 66,102	$ 68,077	$ 75,385
Derivative Assets	366	335	486
Derivative Liabilities	83	127	88
Derivative Instruments, Netting adjustments
Derivative Asset, Netting adjustments	(713)	(812)	(1,115)
Derivative Liability, Netting adjustments	(448)	(500)	(696)
Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	14,791	14,677	20,269
Derivative assets	282	310	500
Derivative liabilities	41	38	30
Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	51,311	53,400	55,116
Derivative assets	858	909	1,224
Derivative liabilities	815	876	1,190
Interest Rate [Member] | Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	14,479	14,487	20,067
Derivative assets	277	306	499
Derivative liabilities	40	37	27
Interest Rate [Member] | Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	44,156	46,173	47,334
Derivative assets	688	733	1,027
Derivative liabilities	647	702	1,000
Foreign Exchange [Member] | Derivatives Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	312	190	202
Derivative assets	5	4	1
Derivative liabilities	1	1	3
Foreign Exchange [Member] | Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	4,653	4,701	4,925
Derivative assets	55	59	70
Derivative liabilities	51	56	65
Commodity [Member] | Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	1,597	1,616	1,801
Derivative assets	110	112	120
Derivative liabilities	105	106	114
Credit [Member] | Derivatives Not Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	905	910	1,056
Derivative assets	5	5	7
Derivative liabilities	12	12	11
Net Derivatives [Member]
Derivatives, Fair Value [Line Items]
Notional Amount	66,102	68,077	75,385
Derivative Assets	427	407	609
Derivative Liabilities	408	414	524
Other Collateral [Member]
Derivatives, Fair Value [Line Items]
Notional Amount
Derivative Assets	(61)	(72)	(123)
Derivative Liabilities	$ (325)	$ (287)	$ (436)