Fair Value Measurements (excluding Consolidated Investment Entities) - Level 3 Financial Instruments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Derivatives Rollforward:
Fair Value, Net Derivative Asset (Liability), Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net gains (losses)
Assets measured on recurring basis | Level 3 | Embedded derivatives on reinsurance .
Derivatives Rollforward:
Fair Value, Derivatives, beginning balance	$ (58)	$ (58)
Total Realized/Unrealized Gains (Losses) Included in Net income	(1)	0	$ (12)
Total Realized/Unrealized Gains (Losses) Included in OCI	0	0
Purchases	0	0
Issuances	0	0
Sales	0	0
Settlements	6	0
Transfers in to Level 3	0	0
Transfers out of Level 3	0	0
Fair Value, Derivatives, ending balance	(53)	(58)	(58)
Change in Unrealized Gains (Losses) in Earnings	0	0
Fair Value, Net Derivative Asset (Liability), Recurring Basis, Still Held, Unrealized Gain (Loss), OCI	0	0
Assets measured on recurring basis | Level 3 | U.S. government agencies and authorities
Assets Rollforward:
Assets, Fair Value, beginning balance	1	1
Total Realized/Unrealized Gains (Losses) Included in Net income	0	0
Total Realized/Unrealized Gains (Losses) Included in OCI	0	0
Purchases	0	0
Issuances	0	0
Sales	0	0
Settlements	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	(1)	0
Assets, Fair Value, ending balance	0	1	1
Change In Unrealized Gains (Losses) Included in Earnings	0	0
Fair Value, Asset (Liability), Recurring Basis, Still Held, Unrealized Gain (Loss), OCI	0	0
Assets measured on recurring basis | Level 3 | U.S. corporate public securities
Assets Rollforward:
Assets, Fair Value, beginning balance	18	20
Total Realized/Unrealized Gains (Losses) Included in Net income	0	1
Total Realized/Unrealized Gains (Losses) Included in OCI	(1)	0
Purchases	49	0
Issuances	0	0
Sales	0	0
Settlements	(7)	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	(3)
Assets, Fair Value, ending balance	59	18	20
Change In Unrealized Gains (Losses) Included in Earnings	0	0
Fair Value, Asset (Liability), Recurring Basis, Still Held, Unrealized Gain (Loss), OCI	(2)	0
Assets measured on recurring basis | Level 3 | U.S. corporate private securities
Assets Rollforward:
Assets, Fair Value, beginning balance	1,526	1,801
Total Realized/Unrealized Gains (Losses) Included in Net income	(4)	1
Total Realized/Unrealized Gains (Losses) Included in OCI	1	22
Purchases	377	142
Issuances	0	0
Sales	(22)	(4)
Settlements	(246)	(219)
Transfers into Level 3	0	79
Transfers out of Level 3	(135)	(296)
Assets, Fair Value, ending balance	1,497	1,526	1,801
Change In Unrealized Gains (Losses) Included in Earnings	0	1
Fair Value, Asset (Liability), Recurring Basis, Still Held, Unrealized Gain (Loss), OCI	(5)	19
Assets measured on recurring basis | Level 3 | Foreign corporate public securities and foreign governments
Assets Rollforward:
Assets, Fair Value, beginning balance	0	3
Total Realized/Unrealized Gains (Losses) Included in Net income	0	0
Total Realized/Unrealized Gains (Losses) Included in OCI	0	0
Purchases	60	0
Issuances	0	0
Sales	0	0
Settlements	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	(3)
Assets, Fair Value, ending balance	60	0	3
Change In Unrealized Gains (Losses) Included in Earnings	0	0
Fair Value, Asset (Liability), Recurring Basis, Still Held, Unrealized Gain (Loss), OCI	0	0
Assets measured on recurring basis | Level 3 | Foreign corporate private securities
Assets Rollforward:
Assets, Fair Value, beginning balance	436	432
Total Realized/Unrealized Gains (Losses) Included in Net income	(8)	3
Total Realized/Unrealized Gains (Losses) Included in OCI	(33)	9
Purchases	35	129
Issuances	0	0
Sales	(9)	(14)
Settlements	(51)	(167)
Transfers into Level 3	51	51
Transfers out of Level 3	0	(7)
Assets, Fair Value, ending balance	421	436	432
Change In Unrealized Gains (Losses) Included in Earnings	0	3
Fair Value, Asset (Liability), Recurring Basis, Still Held, Unrealized Gain (Loss), OCI	(33)	8
Assets measured on recurring basis | Level 3 | Residential mortgage-backed securities
Assets Rollforward:
Assets, Fair Value, beginning balance	57	28
Total Realized/Unrealized Gains (Losses) Included in Net income	(4)	(4)
Total Realized/Unrealized Gains (Losses) Included in OCI	0	0
Purchases	18	31
Issuances	0	0
Sales	0	0
Settlements	0	0
Transfers into Level 3	0	2
Transfers out of Level 3	(4)	0
Assets, Fair Value, ending balance	67	57	28
Change In Unrealized Gains (Losses) Included in Earnings	(4)	(3)
Fair Value, Asset (Liability), Recurring Basis, Still Held, Unrealized Gain (Loss), OCI	0	0
Assets measured on recurring basis | Level 3 | Other asset-backed securities
Assets Rollforward:
Assets, Fair Value, beginning balance	52	64
Total Realized/Unrealized Gains (Losses) Included in Net income	0	0
Total Realized/Unrealized Gains (Losses) Included in OCI	0	1
Purchases	3	15
Issuances	0	0
Sales	0	(2)
Settlements	(7)	(4)
Transfers into Level 3	0	0
Transfers out of Level 3	(25)	(22)
Assets, Fair Value, ending balance	23	52	64
Change In Unrealized Gains (Losses) Included in Earnings	0	0
Fair Value, Asset (Liability), Recurring Basis, Still Held, Unrealized Gain (Loss), OCI	0	0
Assets measured on recurring basis | Level 3 | Fixed maturities
Assets Rollforward:
Assets, Fair Value, beginning balance	2,090	2,349
Total Realized/Unrealized Gains (Losses) Included in Net income	(16)	1
Total Realized/Unrealized Gains (Losses) Included in OCI	(33)	32
Purchases	542	317
Issuances	0	0
Sales	(31)	(20)
Settlements	(311)	(390)
Transfers into Level 3	51	132
Transfers out of Level 3	(165)	(331)
Assets, Fair Value, ending balance	2,127	2,090	2,349
Change In Unrealized Gains (Losses) Included in Earnings	(4)	1
Fair Value, Asset (Liability), Recurring Basis, Still Held, Unrealized Gain (Loss), OCI	(40)	27
Assets measured on recurring basis | Level 3 | Equity securities
Assets Rollforward:
Assets, Fair Value, beginning balance	96	196
Total Realized/Unrealized Gains (Losses) Included in Net income	2	(3)
Total Realized/Unrealized Gains (Losses) Included in OCI	0	0
Purchases	0	3
Issuances	0	0
Sales	0	0
Settlements	0	(100)
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Assets, Fair Value, ending balance	98	96	196
Change In Unrealized Gains (Losses) Included in Earnings	2	(3)
Fair Value, Asset (Liability), Recurring Basis, Still Held, Unrealized Gain (Loss), OCI	0	0
Assets measured on recurring basis | Level 3 | Contingent Consideration
Assets Rollforward:
Fair Value, Asset (Liability), Recurring Basis, Still Held, Unrealized Gain (Loss), OCI	0	0
Liabilities Rollforward:
Liabilities, Beginning Balance	(51)	(112)
Total Realized/Unrealized Gains (Losses) Included in Net income	1	61
Total Realized/Unrealized Gains (Losses) Included in OCI	0	0
Purchases	0	0
Issuances	0	0
Sales	0	0
Settlements	48	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Liabilities, Ending Balance	(2)	(51)	(112)
Change In Unrealized Gains (Losses) Included in Earnings	0	0
Assets measured on recurring basis | Level 3 | Stabilizer and MCGs
Assets Rollforward:
Fair Value, Asset (Liability), Recurring Basis, Still Held, Unrealized Gain (Loss), OCI	0	0
Liabilities Rollforward:
Liabilities, Beginning Balance	(9)	(6)
Total Realized/Unrealized Gains (Losses) Included in Net income	(8)	(1)
Total Realized/Unrealized Gains (Losses) Included in OCI	0	0
Purchases	0	0
Issuances	(2)	(2)
Sales	0	0
Settlements	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Liabilities, Ending Balance	(19)	(9)	(6)
Change In Unrealized Gains (Losses) Included in Earnings	0	0
Assets measured on recurring basis | Level 3 | Assets held in separate accounts
Assets Rollforward:
Assets, Fair Value, beginning balance	348	347
Total Realized/Unrealized Gains (Losses) Included in Net income	6	1
Total Realized/Unrealized Gains (Losses) Included in OCI	0	0
Purchases	47	8
Issuances	0	0
Sales	(26)	(21)
Settlements	0	0
Transfers into Level 3	5	14
Transfers out of Level 3	(40)	(1)
Assets, Fair Value, ending balance	340	348	$ 347
Change In Unrealized Gains (Losses) Included in Earnings	0	0
Fair Value, Asset (Liability), Recurring Basis, Still Held, Unrealized Gain (Loss), OCI	0	$ 0
Assets measured on recurring basis | Level 3 | Cash and cash equivalents
Assets Rollforward:
Purchases	23
Assets, Fair Value, ending balance	$ 23