Derivative Financial Instruments - Notional Value of Derivative Contracts (Detail) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Derivative [Line Items]
Total	$ 5,452,406	$ 5,457,095
Interest rate contracts [Member]
Derivative [Line Items]
Total	3,898,500	3,993,309
Interest rate contracts [Member] | Futures and forwards [Member]
Derivative [Line Items]
Total	165,895	175,468
Interest rate contracts [Member] | Swaps [Member]
Derivative [Line Items]
Total	3,631,662	3,645,085
Interest rate contracts [Member] | Options written [Member]
Derivative [Line Items]
Total	47,508	85,021
Interest rate contracts [Member] | Options purchased [Member]
Derivative [Line Items]
Total	53,435	87,735
Foreign exchange contracts [Member]
Derivative [Line Items]
Total	1,122,370	1,024,123
Foreign exchange contracts [Member] | Options written [Member]
Derivative [Line Items]
Total	111,812	82,817
Foreign exchange contracts [Member] | Options purchased [Member]
Derivative [Line Items]
Total	112,903	84,835
Foreign exchange contracts [Member] | Swaps, futures and forwards [Member]
Derivative [Line Items]
Total	819,858	804,278
Foreign exchange contracts [Member] | Spot [Member]
Derivative [Line Items]
Total	77,797	52,193
Commodity and Equity Contract [Member]
Derivative [Line Items]
Total	95,811	84,377
Commodity and Equity Contract [Member] | Options written [Member]
Derivative [Line Items]
Total	18,007	21,531
Commodity and Equity Contract [Member] | Options purchased [Member]
Derivative [Line Items]
Total	28,884	21,723
Commodity and Equity Contract [Member] | Swaps, futures and forwards [Member]
Derivative [Line Items]
Total	48,920	41,123
Credit contracts [Member]
Derivative [Line Items]
Total	$ 335,725	$ 355,286