Shareholders' equity AOCI (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance – beginning of year, net of tax	$ 59,714	$ 59,441
Balance – end of year, net of tax	50,540	59,714	$ 59,441
AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance – beginning of year, net of tax	2,256	4,673	2,543
OCI, before Reclassifications, before Tax, Attributable to Parent	(11,627)	(2,935)	2,311
Reclassification from AOCI, Current Period, before Tax, Attributable to Parent	1,049	(3)	281
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	(10,578)	(2,938)	2,592
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	1,043	521	(462)
Balance – end of year, net of tax	(7,279)	2,256	4,673
Cumulative Translation Adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance – beginning of year, net of tax	(2,146)	(1,637)	(1,939)
OCI, before Reclassifications, before Tax, Attributable to Parent	(982)	(530)	306
Reclassification from AOCI, Current Period, before Tax, Attributable to Parent	(4)	0	0
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	(986)	(530)	306
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	59	21	(4)
Balance – end of year, net of tax	(3,073)	(2,146)	(1,637)
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance – beginning of year, net of tax	0	0	0
OCI, before Reclassifications, before Tax, Attributable to Parent	17	0	0
Reclassification from AOCI, Current Period, before Tax, Attributable to Parent	(100)	0	0
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	(83)	0	0
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	17	0	0
Balance – end of year, net of tax	(66)	0	0
Accumulated Defined Benefit Plans Adjustment [Member]
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance – beginning of year, net of tax	240	(167)	15
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Parent	(17)	522	(232)
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent	2	(115)	50
Balance – end of year, net of tax	225	240	(167)
Accumulated Other Comprehensive Income
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance – beginning of year, net of tax	350	2,869	619
Balance – end of year, net of tax	$ (10,193)	$ 350	$ 2,869