Derivative Instruments- Revenue from Foreign Exchange and Other Trading (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended			9 Months Ended
	Sep. 30, 2014	Jun. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Trading Activity, Gains and Losses, Net [Line Items]
Foreign exchange	$ 154	$ 129	$ 154	$ 413	$ 482
Other trading revenue	(1)	1	6	6	46
Foreign exchange and other trading revenue	153	130	160	419	528
Fixed Income
Trading Activity, Gains and Losses, Net [Line Items]
Other trading revenue	2	(1)	(2)	2	18
Credit Derivatives/Other
Trading Activity, Gains and Losses, Net [Line Items]
Other trading revenue	$ (3)	$ 2	$ 8	$ 4	$ 28