Derivative Financial Instruments - Notional Value of Derivative Contracts (Detail) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Derivative [Line Items]
Total	$ 4,210,729	$ 4,212,040
Interest rate contracts [Member]
Derivative [Line Items]
Total	2,770,882	2,748,778
Interest Rate Futures and Forwards [Member]
Derivative [Line Items]
Total	247,415	149,413
Interest Rate Swap [Member]
Derivative [Line Items]
Total	2,301,773	2,453,526
Interest Rate Options Written [Member]
Derivative [Line Items]
Total	96,548	65,747
Interest Rate Options Purchased [Member]
Derivative [Line Items]
Total	125,146	80,092
Foreign exchange contracts [Member]
Derivative [Line Items]
Total	1,181,110	1,186,671
Foreign Exchange Swaps, Futures and Forwards [Member]
Derivative [Line Items]
Total	998,941	980,811
Foreign Exchange Options Written [Member]
Derivative [Line Items]
Total	75,580	81,132
Foreign Exchange Options Purchased [Member]
Derivative [Line Items]
Total	76,607	82,004
Foreign Exchange Spot [Member]
Derivative [Line Items]
Total	29,982	42,724
Commodities, equities and precious metals contracts [Member]
Derivative [Line Items]
Total	97,486	88,521
Commodities, Equities and Precious Metals, Swaps, Futures and Forwards [Member]
Derivative [Line Items]
Total	47,941	35,546
Commodities, Equities and Precious Metals Options Written [Member]
Derivative [Line Items]
Total	18,267	19,601
Commodities, Equities and Precious Metals Options Purchased [Member]
Derivative [Line Items]
Total	31,278	33,374
Credit contracts [Member]
Derivative [Line Items]
Total	$ 161,251	$ 188,070