Fair Value - Reconciliations of Assets and Liabilities Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Corporate and Other Bonds
Reconciliations for All Assets and Liabilities [Roll Forward]
Balance at beginning of period	$ 846	$ 883	$ 937	$ 770
Included in Net Income	1	1	(1)	(9)
Included in OCI	(50)	1	(203)	(23)
Purchases	9	55	127	219
Sales			(5)	(3)
Settlements	(4)	(11)	(63)	(35)
Transfers into Level 3			10	10
Transfers out of Level 3		(52)		(52)
Balance at end of period	802	877	802	877
Unrealized Gains (Losses) Recognized in Net Income (Loss) on Level 3 Assets and Liabilities Held at September 30
Unrealized Gains (Losses) Recognized in Other Comprehensive Income (Loss) on Level 3 Assets and Liabilities Held at September 30	(51)	2	(203)	(22)
States, municipalities and political subdivisions
Reconciliations for All Assets and Liabilities [Roll Forward]
Balance at beginning of period	46	57	56	46
Included in Net Income
Included in OCI	(4)		(14)
Purchases				12
Sales
Settlements				(1)
Transfers into Level 3
Transfers out of Level 3
Balance at end of period	42	57	42	57
Unrealized Gains (Losses) Recognized in Net Income (Loss) on Level 3 Assets and Liabilities Held at September 30
Unrealized Gains (Losses) Recognized in Other Comprehensive Income (Loss) on Level 3 Assets and Liabilities Held at September 30	(4)		(14)
Total asset-backed
Reconciliations for All Assets and Liabilities [Roll Forward]
Balance at beginning of period	641	410	556	308
Included in Net Income	7	1	18	4
Included in OCI	(38)	1	(122)	(4)
Purchases	116	83	348	197
Sales		(9)	(2)	(9)
Settlements	(14)	(11)	(54)	(38)
Transfers into Level 3	47	41	66	71
Transfers out of Level 3	(43)	(38)	(94)	(51)
Balance at end of period	716	478	716	478
Unrealized Gains (Losses) Recognized in Net Income (Loss) on Level 3 Assets and Liabilities Held at September 30
Unrealized Gains (Losses) Recognized in Other Comprehensive Income (Loss) on Level 3 Assets and Liabilities Held at September 30	(38)		(121)	(5)
Fixed maturities available-for-sale
Reconciliations for All Assets and Liabilities [Roll Forward]
Balance at beginning of period	1,533	1,350	1,549	1,124
Included in Net Income	8	2	17	(5)
Included in OCI	(92)	2	(339)	(27)
Purchases	125	138	475	428
Sales	0	(9)	(7)	(12)
Settlements	(18)	(22)	(117)	(74)
Transfers into Level 3	47	41	76	81
Transfers out of Level 3	(43)	(90)	(94)	(103)
Balance at end of period	1,560	1,412	1,560	1,412
Unrealized Gains (Losses) Recognized in Net Income (Loss) on Level 3 Assets and Liabilities Held at September 30	0	0	0	0
Unrealized Gains (Losses) Recognized in Other Comprehensive Income (Loss) on Level 3 Assets and Liabilities Held at September 30	(93)	2	(338)	(27)
Fixed maturities trading
Reconciliations for All Assets and Liabilities [Roll Forward]
Balance at beginning of period	0	0	0	8
Included in Net Income				(6)
Included in OCI
Purchases
Sales
Settlements				(2)
Transfers into Level 3
Transfers out of Level 3
Balance at end of period	0	0	0	0
Unrealized Gains (Losses) Recognized in Net Income (Loss) on Level 3 Assets and Liabilities Held at September 30
Unrealized Gains (Losses) Recognized in Other Comprehensive Income (Loss) on Level 3 Assets and Liabilities Held at September 30
Fixed maturity securities
Reconciliations for All Assets and Liabilities [Roll Forward]
Balance at beginning of period	1,533	1,350	1,549	1,132
Included in Net Income	8	2	17	(11)
Included in OCI	(92)	2	(339)	(27)
Purchases	125	138	475	428
Sales	0	(9)	(7)	(12)
Settlements	(18)	(22)	(117)	(76)
Transfers into Level 3	47	41	76	81
Transfers out of Level 3	(43)	(90)	(94)	(103)
Balance at end of period	1,560	1,412	1,560	1,412
Unrealized Gains (Losses) Recognized in Net Income (Loss) on Level 3 Assets and Liabilities Held at September 30	0	0	0	0
Unrealized Gains (Losses) Recognized in Other Comprehensive Income (Loss) on Level 3 Assets and Liabilities Held at September 30	(93)	2	(338)	(27)
Equity securities
Reconciliations for All Assets and Liabilities [Roll Forward]
Balance at beginning of period	47	36	29	43
Included in Net Income	(7)	(2)	(7)	(15)
Included in OCI
Purchases		1	12	11
Sales		(11)	(3)	(15)
Settlements			9
Transfers into Level 3		11		11
Transfers out of Level 3	(10)	(10)	(10)	(10)
Balance at end of period	30	25	30	25
Unrealized Gains (Losses) Recognized in Net Income (Loss) on Level 3 Assets and Liabilities Held at September 30	(7)	(3)	(8)	(1)
Unrealized Gains (Losses) Recognized in Other Comprehensive Income (Loss) on Level 3 Assets and Liabilities Held at September 30