Derivative Financial Instruments - Notional Value of Derivative Contracts (Detail) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Derivative [Line Items]
Total	$ 5,437,400	$ 5,457,095
Interest rate contracts [Member]
Derivative [Line Items]
Total	3,916,589	3,993,309
Interest rate contracts [Member] | Futures and forwards [Member]
Derivative [Line Items]
Total	115,127	175,468
Interest rate contracts [Member] | Swaps [Member]
Derivative [Line Items]
Total	3,694,301	3,645,085
Interest rate contracts [Member] | Options written [Member]
Derivative [Line Items]
Total	46,040	85,021
Interest rate contracts [Member] | Options purchased [Member]
Derivative [Line Items]
Total	61,121	87,735
Foreign exchange contracts [Member]
Derivative [Line Items]
Total	1,147,540	1,024,123
Foreign exchange contracts [Member] | Options written [Member]
Derivative [Line Items]
Total	121,210	82,817
Foreign exchange contracts [Member] | Options purchased [Member]
Derivative [Line Items]
Total	122,574	84,835
Foreign exchange contracts [Member] | Swaps, futures and forwards [Member]
Derivative [Line Items]
Total	843,970	804,278
Foreign exchange contracts [Member] | Spot [Member]
Derivative [Line Items]
Total	59,786	52,193
Commodity and Equity Contract [Member]
Derivative [Line Items]
Total	70,237	84,377
Commodity and Equity Contract [Member] | Options written [Member]
Derivative [Line Items]
Total	12,156	21,531
Commodity and Equity Contract [Member] | Options purchased [Member]
Derivative [Line Items]
Total	10,266	21,723
Commodity and Equity Contract [Member] | Swaps, futures and forwards [Member]
Derivative [Line Items]
Total	47,815	41,123
Credit contracts [Member]
Derivative [Line Items]
Total	$ 303,034	$ 355,286