v3.25.2
Fair Value Measurements (excluding Consolidated Investment Entities) - Fair Value Measurement (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets held in separate accounts $ 107,278 $ 101,676
Total assets 172,436 163,889
Derivatives 309 332
Total liabilities 165,883 157,882
Fixed maturities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 29,089 27,454
U.S. Treasuries    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 546 472
U.S. Government agencies and authorities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 31 30
State, municipalities and political subdivisions    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 516 580
U.S. corporate public securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 7,418 7,008
U.S. corporate private securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 5,388 4,983
Foreign corporate public securities and foreign governments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 2,560 2,472
Foreign corporate private securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 2,892 2,537
Residential mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 3,716 3,471
Commercial mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 3,040 3,132
Other asset-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 2,982 2,769
Measured at fair value on a recurring basis    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash and cash equivalents, short-term investments and short-term investments under securities loan agreements 2,372 2,535
Assets held in separate accounts 107,278 101,676
Total assets 139,210 132,269
Contingent consideration 154 2
Total liabilities 508 394
Measured at fair value on a recurring basis | Stabilizer and MCGs    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Guaranteed benefit derivatives 13 19
Measured at fair value on a recurring basis | Interest rate contracts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives 177 246
Derivatives 271 313
Measured at fair value on a recurring basis | Foreign exchange contracts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives 15 55
Derivatives 34 8
Measured at fair value on a recurring basis | Equity contracts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives 7 2
Derivatives 1 9
Measured at fair value on a recurring basis | Embedded derivatives within reinsurance    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives 62 55
Embedded derivatives within reinsurance 32 41
Measured at fair value on a recurring basis | Credit contracts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives 3 2
Measured at fair value on a recurring basis | Fixed maturities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 29,089 27,454
Measured at fair value on a recurring basis | U.S. Treasuries    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 546 472
Measured at fair value on a recurring basis | U.S. Government agencies and authorities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 31 30
Measured at fair value on a recurring basis | State, municipalities and political subdivisions    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 516 580
Measured at fair value on a recurring basis | U.S. corporate public securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 7,418 7,008
Measured at fair value on a recurring basis | U.S. corporate private securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 5,388 4,983
Measured at fair value on a recurring basis | Foreign corporate public securities and foreign governments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 2,560 2,472
Measured at fair value on a recurring basis | Foreign corporate private securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 2,892 2,537
Measured at fair value on a recurring basis | Residential mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 3,716 3,471
Measured at fair value on a recurring basis | Commercial mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 3,040 3,132
Measured at fair value on a recurring basis | Other asset-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 2,982 2,769
Measured at fair value on a recurring basis | Equity securities, at fair value    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity securities 210 246
Measured at fair value on a recurring basis | Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash and cash equivalents, short-term investments and short-term investments under securities loan agreements 2,302 2,511
Assets held in separate accounts 101,330 95,946
Total assets 104,199 99,007
Contingent consideration 0 0
Total liabilities 0 11
Measured at fair value on a recurring basis | Level 1 | Stabilizer and MCGs    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Guaranteed benefit derivatives 0 0
Measured at fair value on a recurring basis | Level 1 | Interest rate contracts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives 10 0
Derivatives 0 11
Measured at fair value on a recurring basis | Level 1 | Foreign exchange contracts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives 0 0
Derivatives 0 0
Measured at fair value on a recurring basis | Level 1 | Equity contracts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives 0 0
Derivatives 0 0
Measured at fair value on a recurring basis | Level 1 | Embedded derivatives within reinsurance    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives 0 0
Embedded derivatives within reinsurance 0 0
Measured at fair value on a recurring basis | Level 1 | Credit contracts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives 0 0
Measured at fair value on a recurring basis | Level 1 | Fixed maturities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 442 402
Measured at fair value on a recurring basis | Level 1 | U.S. Treasuries    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 442 402
Measured at fair value on a recurring basis | Level 1 | U.S. Government agencies and authorities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 0 0
Measured at fair value on a recurring basis | Level 1 | State, municipalities and political subdivisions    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 0 0
Measured at fair value on a recurring basis | Level 1 | U.S. corporate public securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 0 0
Measured at fair value on a recurring basis | Level 1 | U.S. corporate private securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 0 0
Measured at fair value on a recurring basis | Level 1 | Foreign corporate public securities and foreign governments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 0 0
Measured at fair value on a recurring basis | Level 1 | Foreign corporate private securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 0 0
Measured at fair value on a recurring basis | Level 1 | Residential mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 0 0
Measured at fair value on a recurring basis | Level 1 | Commercial mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 0 0
Measured at fair value on a recurring basis | Level 1 | Other asset-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 0 0
Measured at fair value on a recurring basis | Level 1 | Equity securities, at fair value    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity securities 115 148
Measured at fair value on a recurring basis | Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash and cash equivalents, short-term investments and short-term investments under securities loan agreements 45 1
Assets held in separate accounts 5,601 5,390
Total assets 31,931 30,674
Contingent consideration 0 0
Total liabilities 299 309
Measured at fair value on a recurring basis | Level 2 | Stabilizer and MCGs    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Guaranteed benefit derivatives 0 0
Measured at fair value on a recurring basis | Level 2 | Interest rate contracts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives 167 246
Derivatives 271 302
Measured at fair value on a recurring basis | Level 2 | Foreign exchange contracts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives 15 55
Derivatives 34 8
Measured at fair value on a recurring basis | Level 2 | Equity contracts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives 7 2
Derivatives 1 9
Measured at fair value on a recurring basis | Level 2 | Embedded derivatives within reinsurance    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives 62 55
Embedded derivatives within reinsurance (10) (12)
Measured at fair value on a recurring basis | Level 2 | Credit contracts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives 3 2
Measured at fair value on a recurring basis | Level 2 | Fixed maturities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 26,034 24,925
Measured at fair value on a recurring basis | Level 2 | U.S. Treasuries    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 104 70
Measured at fair value on a recurring basis | Level 2 | U.S. Government agencies and authorities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 31 30
Measured at fair value on a recurring basis | Level 2 | State, municipalities and political subdivisions    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 516 580
Measured at fair value on a recurring basis | Level 2 | U.S. corporate public securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 7,370 6,949
Measured at fair value on a recurring basis | Level 2 | U.S. corporate private securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 3,713 3,486
Measured at fair value on a recurring basis | Level 2 | Foreign corporate public securities and foreign governments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 2,498 2,412
Measured at fair value on a recurring basis | Level 2 | Foreign corporate private securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 2,256 2,116
Measured at fair value on a recurring basis | Level 2 | Residential mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 3,618 3,404
Measured at fair value on a recurring basis | Level 2 | Commercial mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 3,040 3,132
Measured at fair value on a recurring basis | Level 2 | Other asset-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 2,888 2,746
Measured at fair value on a recurring basis | Level 2 | Equity securities, at fair value    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity securities 0 0
Measured at fair value on a recurring basis | Level 3    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Cash and cash equivalents, short-term investments and short-term investments under securities loan agreements 25 23
Assets held in separate accounts 347 340
Total assets 3,080 2,588
Contingent consideration 154 2
Total liabilities 209 74
Measured at fair value on a recurring basis | Level 3 | Stabilizer and MCGs    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Guaranteed benefit derivatives 13 19
Measured at fair value on a recurring basis | Level 3 | Interest rate contracts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives 0 0
Derivatives 0 0
Measured at fair value on a recurring basis | Level 3 | Foreign exchange contracts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives 0 0
Derivatives 0 0
Measured at fair value on a recurring basis | Level 3 | Equity contracts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives 0 0
Derivatives 0 0
Measured at fair value on a recurring basis | Level 3 | Embedded derivatives within reinsurance    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives 0 0
Embedded derivatives within reinsurance 42 53
Measured at fair value on a recurring basis | Level 3 | Credit contracts    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Derivatives 0 0
Measured at fair value on a recurring basis | Level 3 | Fixed maturities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 2,613 2,127
Measured at fair value on a recurring basis | Level 3 | U.S. Treasuries    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 0 0
Measured at fair value on a recurring basis | Level 3 | U.S. Government agencies and authorities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 0 0
Measured at fair value on a recurring basis | Level 3 | State, municipalities and political subdivisions    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 0 0
Measured at fair value on a recurring basis | Level 3 | U.S. corporate public securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 48 59
Measured at fair value on a recurring basis | Level 3 | U.S. corporate private securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 1,675 1,497
Measured at fair value on a recurring basis | Level 3 | Foreign corporate public securities and foreign governments    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 62 60
Measured at fair value on a recurring basis | Level 3 | Foreign corporate private securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 636 421
Measured at fair value on a recurring basis | Level 3 | Residential mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 98 67
Measured at fair value on a recurring basis | Level 3 | Commercial mortgage-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 0 0
Measured at fair value on a recurring basis | Level 3 | Other asset-backed securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fixed maturities, including securities pledged 94 23
Measured at fair value on a recurring basis | Level 3 | Equity securities, at fair value    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Equity securities $ 95 $ 98