Variable Interest Entities (VIEs) (Impact Of VIEs On The Consolidated Statements Of Comprehensive Income) (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020		Jun. 30, 2021	Jun. 30, 2020
Variable Interest Entity
Provision for income taxes	$ 93	$ 28	[1]	$ 191	$ 9	[1]
Variable Interest Entity
Variable Interest Entity
Provision for income taxes	(3)	(2)		(6)	(5)
Low income housing tax credits | Variable Interest Entity
Variable Interest Entity
Provision for income taxes, amortization of LIHTC investments	18	17		35	34
Provision for income taxes, affordable housing tax credits and other tax benefits	(17)	(16)		(33)	(32)
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)		$ (8)	$ (7)

[1] See Defined Benefit Pension and Other Postretirement Costs in Note 1.