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
	Mar. 31, 2023	Mar. 31, 2022
Corporate bonds and other
Reconciliations for All Assets and Liabilities [Roll Forward]
Balance at beginning of period	$ 810	$ 937
Included in Net Income		(1)
Included in OCI	24	(71)
Purchases	81	67
Sales		(5)
Settlements	(3)	(22)
Transfers into Level 3		10
Transfers out of Level 3
Balance at end of period	912	915
Unrealized Gains (Losses) Recognized in Net Income (Loss) on Level 3 Assets and Liabilities Held at March 31
Unrealized Gains (Losses) Recognized in Other Comprehensive Income (Loss) on Level 3 Assets and Liabilities Held at March 31	24	(72)
States, municipalities and political subdivisions
Reconciliations for All Assets and Liabilities [Roll Forward]
Balance at beginning of period	43	56
Included in Net Income
Included in OCI	1	(5)
Purchases
Sales
Settlements
Transfers into Level 3
Transfers out of Level 3
Balance at end of period	44	51
Unrealized Gains (Losses) Recognized in Net Income (Loss) on Level 3 Assets and Liabilities Held at March 31
Unrealized Gains (Losses) Recognized in Other Comprehensive Income (Loss) on Level 3 Assets and Liabilities Held at March 31	1	(5)
Asset-backed
Reconciliations for All Assets and Liabilities [Roll Forward]
Balance at beginning of period	788	556
Included in Net Income	5	3
Included in OCI	7	(32)
Purchases	55	140
Sales
Settlements	(9)	(17)
Transfers into Level 3	23	5
Transfers out of Level 3	(10)	(51)
Balance at end of period	859	604
Unrealized Gains (Losses) Recognized in Net Income (Loss) on Level 3 Assets and Liabilities Held at March 31
Unrealized Gains (Losses) Recognized in Other Comprehensive Income (Loss) on Level 3 Assets and Liabilities Held at March 31	7	(31)
Fixed maturities available-for-sale
Reconciliations for All Assets and Liabilities [Roll Forward]
Balance at beginning of period	1,641	1,549
Included in Net Income	5	2
Included in OCI	32	(108)
Purchases	136	207
Sales	0	(5)
Settlements	(12)	(39)
Transfers into Level 3	23	15
Transfers out of Level 3	(10)	(51)
Balance at end of period	1,815	1,570
Unrealized Gains (Losses) Recognized in Net Income (Loss) on Level 3 Assets and Liabilities Held at March 31	0	0
Unrealized Gains (Losses) Recognized in Other Comprehensive Income (Loss) on Level 3 Assets and Liabilities Held at March 31	32	(108)
Fixed maturities trading
Reconciliations for All Assets and Liabilities [Roll Forward]
Balance at beginning of period	0	0
Included in Net Income
Included in OCI
Purchases
Sales
Settlements
Transfers into Level 3
Transfers out of Level 3
Balance at end of period	0	0
Unrealized Gains (Losses) Recognized in Net Income (Loss) on Level 3 Assets and Liabilities Held at March 31
Unrealized Gains (Losses) Recognized in Other Comprehensive Income (Loss) on Level 3 Assets and Liabilities Held at March 31
Fixed maturity securities
Reconciliations for All Assets and Liabilities [Roll Forward]
Balance at beginning of period	1,641	1,549
Included in Net Income	5	2
Included in OCI	32	(108)
Purchases	136	207
Sales	0	(5)
Settlements	(12)	(39)
Transfers into Level 3	23	15
Transfers out of Level 3	(10)	(51)
Balance at end of period	1,815	1,570
Unrealized Gains (Losses) Recognized in Net Income (Loss) on Level 3 Assets and Liabilities Held at March 31	0	0
Unrealized Gains (Losses) Recognized in Other Comprehensive Income (Loss) on Level 3 Assets and Liabilities Held at March 31	32	(108)
Equity securities
Reconciliations for All Assets and Liabilities [Roll Forward]
Balance at beginning of period	35	29
Included in Net Income	(6)	3
Included in OCI
Purchases		12
Sales
Settlements
Transfers into Level 3
Transfers out of Level 3
Balance at end of period	29	44
Unrealized Gains (Losses) Recognized in Net Income (Loss) on Level 3 Assets and Liabilities Held at March 31	(6)	3
Unrealized Gains (Losses) Recognized in Other Comprehensive Income (Loss) on Level 3 Assets and Liabilities Held at March 31