Derivative Instruments - Revenue from Foreign Exchange and Other Trading (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Foreign exchange	$ 171	$ 165	$ 217
Other trading revenue	4	8	12
Total foreign exchange and other trading revenue	$ 175	$ 173	$ 229