Investments (Components of Net Investment Gains Losses) (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Marketable Securities, Gain (Loss) [Abstract]
Fixed maturity securities AFS - net gains (losses) on sales and disposals	$ 158	$ 138	$ 377	$ 124
Equity securities - net gains (losses) on sales and disposals	3	4	11	47
Change In Estimated Fair Value Of Equity Securities	69	(6)	(223)	58
Other net investment gains (losses):
Mortgage loans	(80)	14	(143)	(1)
Real estate and real estate joint ventures	2	1	3	6
Other limited partnership interests	1	0	5	0
Other (3), (4)	97	(42)	122	(110)
Subtotal - investment portfolio gains (losses)	242	109	(71)	114
Change In Estimated Fair Value Of Other Limited Partnership Interests And Real Estate Joint Ventures	(13)	3	(12)	(12)
Non-investment portfolio gains (losses)	2	(51)	26	(26)
Subtotal	(11)	(48)	14	(38)
Total net investment gains (losses)	231	61	(57)	76
Changes In Estimated Fair Value Subsequent To Purchase For Equity Securities	63	(1)	(193)	92
Gain (Loss) on Termination of Lease	81		81
Fixed Maturity Securities
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings		0		(10)
Current expected credit loss recognized in earnings	(8)		(223)
Net investment gains (losses)	150	138	154	114
Equity Securities
Marketable Securities, Gain (Loss) [Abstract]
Net investment gains (losses)	72	(2)	(212)	105
Industrial Domestic Corporate Debt Securities [Member]
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings				(8)
RMBS
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings				(2)
Tax credit partnerships
Marketable Securities, Gain (Loss) [Abstract]
Total OTTI losses recognized in earnings		(14)		(92)
Other limited partnership interests
Other net investment gains (losses):
Other (3), (4)				46
Cash Flow Hedging [Member]
Other net investment gains (losses):
Total net investment gains (losses)	79	(4)	87	(19)
Currency Swap [Member] \| Cash Flow Hedging [Member]
Other net investment gains (losses):
Total net investment gains (losses)	287	$ 83	(164)	$ 108
Foreign Currency Gain (Loss) [Member] \| Reclassification out of Accumulated Other Comprehensive Income \| Currency Swap [Member] \| Cash Flow Hedging [Member]
Other net investment gains (losses):
Total net investment gains (losses)	$ 43		$ 55

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