Securities (Gains and Losses Recognized in Income from Trading Securities) (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Securities
Realized gains	[1]	$ 3	$ 2
Realized losses	[2]	(2)	(4)
Net unrealized gains (losses)	[3]	1	1
Total trading securities gains (losses)		$ 2	$ (1)

[1] Includes realized gains of $ 3 and $ 2 for the three months ended March 31, 2017 and 2016 , respectively, reco rded in corporate banking revenu e and wealth and asset management revenue in the Condensed Consolidated Statements of Income.

[2] Includes realized losses of $ 2 and $ 4 for the three months ended March 31, 2017 and 2016 , respectively, recorded in corporate banking revenue and wealth and asset management revenue in the Condensed Consolidated Statements of Income.

[3] Includes an immaterial amount of net unrealized gains for both the three months ended March 31, 2017 and 2016 recorded in corporate banking revenue and wealth and asset management revenue in the Condensed Consolidated Statements of Income.