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Investments - Gross unrealized losses on securities by investment category and length of time that have been in a continuous unrealized loss position (Details) - USD ($) $ in Millions | Dec. 31, 2023 | Dec. 31, 2022
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Fixed maturities |  |
Available-for-sale securities in a continuous unrealized loss position |  |
Unrealized loss - less than twelve months | $ (7) | $ (425)
Fair value - less than twelve months | $ 428 | $ 6,540
Fair value as percentage of cost - less than twelve months | 98.00% | 94.00%
Unrealized loss - twelve months or more | $ (463) | $ (244)
Fair value - twelve months or more | $ 5,999 | $ 2,344
Fair value as a percentage of cost - twelve months or more | 93.00% | 91.00%
U.S. Government and government agencies |  |
Available-for-sale securities in a continuous unrealized loss position |  |
Unrealized loss - less than twelve months | $ 0 | $ (4)
Fair value - less than twelve months | $ 11 | $ 111
Fair value as percentage of cost - less than twelve months | 100.00% | 97.00%
Unrealized loss - twelve months or more | $ (8) | $ (10)
Fair value - twelve months or more | $ 191 | $ 107
Fair value as a percentage of cost - twelve months or more | 96.00% | 91.00%
States, municipalities and political subdivisions |  |
Available-for-sale securities in a continuous unrealized loss position |  |
Unrealized loss - less than twelve months | $ (1) | $ (50)
Fair value - less than twelve months | $ 76 | $ 967
Fair value as percentage of cost - less than twelve months | 99.00% | 95.00%
Unrealized loss - twelve months or more | $ (37) | $ (1)
Fair value - twelve months or more | $ 526 | $ 15
Fair value as a percentage of cost - twelve months or more | 93.00% | 94.00%
Foreign government |  |
Available-for-sale securities in a continuous unrealized loss position |  |
Unrealized loss - less than twelve months | $ 0 | $ (5)
Fair value - less than twelve months | $ 0 | $ 90
Fair value as percentage of cost - less than twelve months | 0.00% | 95.00%
Unrealized loss - twelve months or more | $ (7) | $ (9)
Fair value - twelve months or more | $ 207 | $ 134
Fair value as a percentage of cost - twelve months or more | 97.00% | 94.00%
Residential MBS |  |
Available-for-sale securities in a continuous unrealized loss position |  |
Unrealized loss - less than twelve months | $ (1) | $ (115)
Fair value - less than twelve months | $ 42 | $ 1,078
Fair value as percentage of cost - less than twelve months | 98.00% | 90.00%
Unrealized loss - twelve months or more | $ (154) | $ (65)
Fair value - twelve months or more | $ 1,089 | $ 315
Fair value as a percentage of cost - twelve months or more | 88.00% | 83.00%
Commercial MBS |  |
Available-for-sale securities in a continuous unrealized loss position |  |
Unrealized loss - less than twelve months | $ 0 | $ (2)
Fair value - less than twelve months | $ 0 | $ 44
Fair value as percentage of cost - less than twelve months | 0.00% | 96.00%
Unrealized loss - twelve months or more | $ (1) | $ (1)
Fair value - twelve months or more | $ 61 | $ 33
Fair value as a percentage of cost - twelve months or more | 98.00% | 97.00%
Collateralized loan obligations |  |
Available-for-sale securities in a continuous unrealized loss position |  |
Unrealized loss - less than twelve months | $ 0 | $ (44)
Fair value - less than twelve months | $ 25 | $ 1,224
Fair value as percentage of cost - less than twelve months | 100.00% | 97.00%
Unrealized loss - twelve months or more | $ (28) | $ (23)
Fair value - twelve months or more | $ 807 | $ 587
Fair value as a percentage of cost - twelve months or more | 97.00% | 96.00%
Other asset-backed securities |  |
Available-for-sale securities in a continuous unrealized loss position |  |
Unrealized loss - less than twelve months | $ (1) | $ (100)
Fair value - less than twelve months | $ 151 | $ 1,361
Fair value as percentage of cost - less than twelve months | 99.00% | 93.00%
Unrealized loss - twelve months or more | $ (119) | $ (84)
Fair value - twelve months or more | $ 1,663 | $ 740
Fair value as a percentage of cost - twelve months or more | 93.00% | 90.00%
Corporate and other |  |
Available-for-sale securities in a continuous unrealized loss position |  |
Unrealized loss - less than twelve months | $ (4) | $ (105)
Fair value - less than twelve months | $ 123 | $ 1,665
Fair value as percentage of cost - less than twelve months | 97.00% | 94.00%
Unrealized loss - twelve months or more | $ (109) | $ (51)
Fair value - twelve months or more | $ 1,455 | $ 413
Fair value as a percentage of cost - twelve months or more | 93.00% | 89.00%

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