Fair Value Measurements (excluding Consolidated Investment Entities) - Fair Value Measurement (Details) - USD ($) $ in Millions | Sep. 30, 2024 | Dec. 31, 2023 |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Assets held in separate accounts | $ 103,532 | $ 93,133 |
Total assets | 166,933 | 157,085 |
Derivatives | 359 | 371 |
Total liabilities | 160,351 | 151,032 |
Fixed maturities | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Fixed maturities, including securities pledged | 28,546 | 28,611 |
U.S. Treasuries | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Fixed maturities, including securities pledged | 374 | 403 |
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 | 56 |
State, municipalities and political subdivisions | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Fixed maturities, including securities pledged | 635 | 771 |
U.S. corporate public securities | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Fixed maturities, including securities pledged | 7,253 | 7,666 |
U.S. corporate private securities | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Fixed maturities, including securities pledged | 4,995 | 4,760 |
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 | 2,549 | 2,702 |
Foreign corporate private securities | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Fixed maturities, including securities pledged | 2,712 | 2,812 |
Residential mortgage-backed securities | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Fixed maturities, including securities pledged | 3,819 | 3,476 |
Commercial mortgage-backed securities | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Fixed maturities, including securities pledged | 3,393 | 3,495 |
Other asset-backed securities | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Fixed maturities, including securities pledged | 2,785 | 2,470 |
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 | 2,822 | 2,165 |
Assets held in separate accounts | 103,532 | 93,133 |
Total assets | 135,416 | 124,517 |
Contingent consideration | 35 | 51 |
Total liabilities | 449 | 480 |
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 | 10 | 9 |
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 | 195 | 270 |
Derivatives | 338 | 354 |
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 | 23 | 37 |
Derivatives | 16 | 13 |
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 | 4 |
Derivatives | 3 | 2 |
Measured at fair value on a recurring basis | Embedded derivative on reinsurance | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivatives | 40 | 61 |
Embedded derivative on reinsurance | 45 | 49 |
Measured at fair value on a recurring basis | Credit contracts | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivatives | 2 | 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 | 28,546 | 28,611 |
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 | 374 | 403 |
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 | 56 |
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 | 635 | 771 |
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 | 7,253 | 7,666 |
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 | 4,995 | 4,760 |
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 | 2,549 | 2,702 |
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 | 2,712 | 2,812 |
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 | 3,819 | 3,476 |
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 | 3,393 | 3,495 |
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 | 2,785 | 2,470 |
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 | 251 | 236 |
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 | 2,808 | 2,148 |
Assets held in separate accounts | 97,372 | 87,180 |
Total assets | 100,650 | 89,821 |
Contingent consideration | 0 | 0 |
Total liabilities | 1 | 0 |
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 | 2 | 7 |
Derivatives | 1 | 0 |
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 derivative on reinsurance | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivatives | 0 | 0 |
Embedded derivative on 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 | 319 | 346 |
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 | 319 | 346 |
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 | 149 | 140 |
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 | 14 | 17 |
Assets held in separate accounts | 5,812 | 5,605 |
Total assets | 32,282 | 32,162 |
Contingent consideration | 0 | 0 |
Total liabilities | 351 | 362 |
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 | 193 | 263 |
Derivatives | 337 | 354 |
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 | 23 | 37 |
Derivatives | 16 | 13 |
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 | 4 |
Derivatives | 3 | 2 |
Measured at fair value on a recurring basis | Level 2 | Embedded derivative on reinsurance | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivatives | 40 | 61 |
Embedded derivative on reinsurance | (7) | (9) |
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 | 2 | 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 | 26,193 | 26,175 |
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 | 55 | 57 |
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 | 55 |
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 | 635 | 771 |
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 | 7,242 | 7,648 |
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 | 3,550 | 3,234 |
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 | 2,539 | 2,702 |
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 | 2,244 | 2,376 |
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 | 3,753 | 3,419 |
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 | 3,393 | 3,495 |
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 | 2,751 | 2,418 |
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 | 0 | 0 |
Assets held in separate accounts | 348 | 348 |
Total assets | 2,484 | 2,534 |
Contingent consideration | 35 | 51 |
Total liabilities | 97 | 118 |
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 | 10 | 9 |
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 derivative on reinsurance | | |
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | | |
Derivatives | 0 | 0 |
Embedded derivative on reinsurance | 52 | 58 |
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 | 2,034 | 2,090 |
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 | 1 |
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 | 11 | 18 |
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 | 1,445 | 1,526 |
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 | 10 | 0 |
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 | 468 | 436 |
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 | 66 | 57 |
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 | 34 | 52 |
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 | $ 102 | $ 96 |