AOCI Rollforward (Details 2) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		$ (295)	$ 35	$ 262	$ (291)
OCI before reclassifications		692	234	129	565
Amounts reclassified from AOCI		(3)	0	3	(5)
Total other comprehensive income (loss), net of tax		689	234	132	560
Ending balance		394	269	394	269
Accumulated Other Comprehensive Income (Loss) Available For Sale Securities Impairment Other than Credit			1		1
Net unrealized gains (losses) on securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		52	342	576	20
OCI before reclassifications		700	248	170	574
Amounts reclassified from AOCI		(3)	0	3	(4)
Total other comprehensive income (loss), net of tax		697	248	173	570
Ending balance	[1]	749	590	749	590
Net unrealized gains (losses) on derivatives [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		6	7	6	8
OCI before reclassifications		0	0	0	0
Amounts reclassified from AOCI		0	0	0	(1)
Total other comprehensive income (loss), net of tax		0	0	0	(1)
Ending balance		6	7	6	7
Defined benefit plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(138)	(120)	(138)	(120)
OCI before reclassifications		0	0	0	0
Amounts reclassified from AOCI		0	0	0	0
Total other comprehensive income (loss), net of tax		0	0	0	0
Ending balance		(138)	(120)	(138)	(120)
Foreign currency translation [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(214)	(193)	(181)	(198)
OCI before reclassifications		(8)	(14)	(41)	(9)
Amounts reclassified from AOCI		0	0	0	0
Total other comprehensive income (loss), net of tax		(8)	(14)	(41)	(9)
Ending balance		(222)	(207)	(222)	(207)
Other [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance		(1)	(1)	(1)	(1)
OCI before reclassifications		0	0	0	0
Amounts reclassified from AOCI		0	0	0	0
Total other comprehensive income (loss), net of tax		0	0	0	0
Ending balance		$ (1)	$ (1)	$ (1)	$ (1)

[1] Includes nil and $(1) million of noncredit related impairments on securities and net unrealized gains (losses) on previously impaired securities as of June 30, 2020 and June 30, 2019, respectively.