Investments - Unrealized Capital Losses (Details) $ in Millions | Sep. 30, 2022 USD ($) securities | Dec. 31, 2021 USD ($) securities |
Available-for-sale Securities Including Securities Pledged [Line Items] | | |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | securities | 3,596 | 989 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss | $ 2,916 | $ 111 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months | $ 2,330 | $ 72 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | securities | 4,320 | 1,326 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | securities | 724 | 337 |
Debt Securities, Available-for-sale, Unrealized Loss Position | $ 1,944 | $ 708 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value | 17,309 | 3,838 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer | 586 | 39 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value | $ 19,253 | $ 4,546 |
U.S. Treasuries | | |
Available-for-sale Securities Including Securities Pledged [Line Items] | | |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | securities | 21 | 4 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss | $ 28 | $ 0 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months | $ 28 | $ 0 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | securities | 23 | 6 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | securities | 2 | 2 |
Debt Securities, Available-for-sale, Unrealized Loss Position | $ 6 | $ 7 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value | 253 | 7 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer | 0 | 0 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value | $ 259 | $ 14 |
State, municipalities and political subdivisions | | |
Available-for-sale Securities Including Securities Pledged [Line Items] | | |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | securities | 295 | 21 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss | $ 90 | $ 1 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months | $ 89 | $ 1 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | securities | 299 | 21 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | securities | 4 | 0 |
Debt Securities, Available-for-sale, Unrealized Loss Position | $ 2 | $ 0 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value | 582 | 33 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer | 1 | 0 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value | $ 584 | $ 33 |
U.S. corporate public securities | | |
Available-for-sale Securities Including Securities Pledged [Line Items] | | |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | securities | 1,068 | 290 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss | $ 1,198 | $ 39 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months | $ 862 | $ 32 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | securities | 1,351 | 428 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | securities | 283 | 138 |
Debt Securities, Available-for-sale, Unrealized Loss Position | $ 712 | $ 110 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value | 4,922 | 1,237 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer | 336 | 7 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value | $ 5,634 | $ 1,347 |
U.S. corporate private securities | | |
Available-for-sale Securities Including Securities Pledged [Line Items] | | |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | securities | 331 | 35 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss | $ 381 | $ 15 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months | $ 343 | $ 2 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | securities | 349 | 43 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | securities | 18 | 8 |
Debt Securities, Available-for-sale, Unrealized Loss Position | $ 205 | $ 94 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value | 2,918 | 325 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer | 38 | 13 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value | $ 3,123 | $ 419 |
Foreign corporate public securities and foreign governments | | |
Available-for-sale Securities Including Securities Pledged [Line Items] | | |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | securities | 406 | 90 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss | $ 376 | $ 14 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months | $ 288 | $ 13 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | securities | 477 | 107 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | securities | 71 | 17 |
Debt Securities, Available-for-sale, Unrealized Loss Position | $ 192 | $ 21 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value | 1,684 | 425 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer | 88 | 1 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value | $ 1,876 | $ 446 |
Foreign corporate private securities | | |
Available-for-sale Securities Including Securities Pledged [Line Items] | | |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | securities | 218 | 7 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss | $ 250 | $ 1 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months | $ 248 | $ 1 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | securities | 221 | 8 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | securities | 3 | 1 |
Debt Securities, Available-for-sale, Unrealized Loss Position | $ 12 | $ 10 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value | 2,289 | 54 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer | 2 | 0 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value | $ 2,301 | $ 64 |
Residential mortgage-backed | | |
Available-for-sale Securities Including Securities Pledged [Line Items] | | |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | securities | 435 | 181 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss | $ 153 | $ 20 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months | $ 100 | $ 11 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | securities | 612 | 277 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | securities | 177 | 96 |
Debt Securities, Available-for-sale, Unrealized Loss Position | $ 316 | $ 241 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value | 1,267 | 400 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer | 53 | 9 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value | $ 1,583 | $ 641 |
Commercial mortgage-backed | | |
Available-for-sale Securities Including Securities Pledged [Line Items] | | |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | securities | 471 | 178 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss | $ 310 | $ 15 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months | $ 260 | $ 8 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | securities | 555 | 205 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | securities | 84 | 27 |
Debt Securities, Available-for-sale, Unrealized Loss Position | $ 358 | $ 155 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value | 2,255 | 780 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer | 50 | 7 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value | $ 2,613 | $ 935 |
Other asset-backed securities | | |
Available-for-sale Securities Including Securities Pledged [Line Items] | | |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | securities | 349 | 183 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss | $ 127 | $ 6 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months | $ 109 | $ 4 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | securities | 431 | 231 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | securities | 82 | 48 |
Debt Securities, Available-for-sale, Unrealized Loss Position | $ 141 | $ 70 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value | 1,122 | 577 |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer | 18 | 2 |
Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value | $ 1,263 | $ 647 |
US Government Corporations and Agencies Securities | | |
Available-for-sale Securities Including Securities Pledged [Line Items] | | |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Number of Positions | securities | 2 | |
Debt Securities, Available-for-sale, Unrealized Loss Position, Accumulated Loss | $ 3 | |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months | $ 3 | |
Debt Securities, Available-for-sale, Unrealized Loss Position, Number of Positions | securities | 2 | |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer, Number of Positions | securities | 0 | |
Debt Securities, Available-for-sale, Unrealized Loss Position | $ 0 | |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, Less than 12 Months, Fair Value | 17 | |
Debt Securities, Available-for-sale, Continuous Unrealized Loss Position, 12 Months or Longer | 0 | |
Debt Securities, Available-for-sale, Unrealized Loss Position, Fair Value | $ 17 | |