Investment Securities (Gains and Losses Recognized in Income from Securities) (Detail) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Securities
Available-for-sale debt and other securities, realized gains		$ 1	$ 13
Available-for-sale debt and other securities, realized losses		(1)	(14)
Net realized gains (losses) on available-for-sale debt and other securities		0	(1)
Total trading debt securities gains		3	3
Total equity securities (losses) gains	[1]	(24)	17
Total (losses) gains available for sale debt and other, trading debt and equity securities recognized in income	[2]	$ (21)	$ 19

[1] Includes net unrealized losses of $23 and net unrealized gains of $19 for the three months ended March 31, 2020 and 2019, respectively.

[2] Excludes $2 of net securities losses for the three months ended March 31, 2020 and $3 of securities gains for the three months ended March 31, 2019 included in commercial banking revenue and wealth and asset management revenue in the Condensed Consolidated Statements of Income related to securities held by FTS to facilitate the timely execution of customer transactions.