Investment Securities (Gains and Losses Recognized in Income from Securities) (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Securities
Available-for-sale debt and other securities, realized gains		$ 60	$ 72	$ 85
Available-for-sale debt and other securities, realized losses		(50)	(82)	(36)
OTTI		(1)	0	(54)
Net realized gains (losses) on available-for-sale debt and other securities		9	(10)	(5)
Total trading debt securities gains (losses)		3	(15)	2
Total equity securities gains (losses)	[1]	31	(44)	7
Total available for sale debt and other, trading debt and equity securities gains (losses) recognized in income	[2]	$ 43	$ (69)	$ 4

[1] Includes $26 of net unrealized gains, $45 of net unrealized losses and $5 of net unrealized gains for the years ended December 31, 2019, 2018 and 2017, respectively.

[2] Excludes $7 of net securities gains for the year ended December 31, 2019 and an insignificant amount of net securities gains (losses) for both the years ended December 31, 2018 and 2017 included in corporate banking revenue and wealth and asset management revenue in the Consolidated Statements of Income related to securities held by FTS to facilitate the timely execution of customer transactions.