Accumulated Other Comprehensive Loss (Reclassification Out of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before tax	$ (5,197)	$ (1,032)	$ 666
Other comprehensive income (loss), tax effect	1,296	243	(158)
Other comprehensive (loss) income, net of tax	(3,901)	(789)	508
Investment securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized gains (losses) arising during the period, before tax	(5,222)	(859)	737
Net unrealized gains (losses) arising during the period, tax	1,240	203	(173)
Net unrealized gains (losses) arising during the period, net of tax	(3,982)	(656)	564
Net realized gains reclassified to income from continuing operations, before tax	23	102	171
Net realized gains reclassified to income from continuing operations, tax	(5)	(23)	(39)
Net realized gains reclassified to income from continuing operations, net of tax	18	79	132
Other comprehensive income (loss), before tax	(5,245)	(961)	566
Other comprehensive income (loss), tax effect	1,245	226	(134)
Other comprehensive (loss) income, net of tax	(4,000)	(735)	432
Translation adjustments and net investment hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before tax	(10)		4
Other comprehensive income (loss), tax effect	2		(1)
Other comprehensive (loss) income, net of tax	(8)		3
Net investment hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before tax	8		(4)
Other comprehensive income (loss), tax effect	(1)		1
Other comprehensive (loss) income, net of tax	7		(3)
Cash flow hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized gains (losses) arising during the period, before tax	(2)		169
Net unrealized gains (losses) arising during the period, tax	0		(40)
Net unrealized gains (losses) arising during the period, net of tax	(2)		129
Net realized gains reclassified to income from continuing operations, before tax	21	61	64
Net realized gains reclassified to income from continuing operations, tax	(6)	(14)	(15)
Net realized gains reclassified to income from continuing operations, net of tax	15	47	49
Other comprehensive income (loss), before tax	(23)		105
Other comprehensive income (loss), tax effect	6		(25)
Other comprehensive (loss) income, net of tax	(17)		80
Defined benefit pension plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized gains (losses) arising during the period, before tax	2	(11)
Net unrealized gains (losses) arising during the period, tax	0	3
Net unrealized gains (losses) arising during the period, net of tax	2	(8)	(4)
Net realized gains reclassified to income from continuing operations, before tax	(71)	(1)
Net realized gains reclassified to income from continuing operations, tax	(44)	0
Net realized gains reclassified to income from continuing operations, net of tax	(115)	(1)
Other comprehensive income (loss), before tax	73	(10)	(5)
Other comprehensive income (loss), tax effect	44	3	$ 1
Other comprehensive (loss) income, net of tax	$ 117	$ (7)