Segment information Segment Information (narrative Detail (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Segment Reporting Information [Line Items]
Gain (Loss) on Derivative		$ 160	$ (123)	$ (223)	$ 424
Net investment income		884	827	1,747	1,688
Gains(Losses) On Fair Value Changes In Separate Account Assets	[1]	(15)	(40)	(19)	16
North America Agricultural Insurance [Member]
Segment Reporting Information [Line Items]
Net investment income		8	7	15	16
Segment Life [Member]
Segment Reporting Information [Line Items]
Net investment income		$ 101	$ 95	$ 199	$ 190

[1] Related to gains (losses) from fair value changes in separate account assets that do not qualify for separate account reporting under GAAP.