Variable Interest Entities (VIEs) (Impact Of VIEs On The Consolidated Statements Of Comprehensive Income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Variable Interest Entity
Other noninterest income	$ 29	$ 23	$ 84	$ 70
Provision for income taxes	48	80	54	252
Variable Interest Entity
Variable Interest Entity
Other noninterest income	0	0	0	1
Provision for income taxes	(4)	(3)	(9)	(8)
Low income housing tax credits | Variable Interest Entity
Variable Interest Entity
Provision for income taxes, amortization of LIHTC investments	17	16	51	48
Provision for income taxes, affordable housing tax credits and other tax benefits	(17)	(16)	(49)	(46)
Other tax benefits related to tax credit entities | Variable Interest Entity
Variable Interest Entity
Provision for income taxes, affordable housing tax credits and other tax benefits	$ (4)	$ (3)	$ (11)	$ (10)