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Investments - Gross Unrealized Loss by Length of Time (Details) $ in Millions | Mar. 31, 2024 USD ($) security | Dec. 31, 2023 USD ($) security
--- | --- | ---
Less than 12 months |  |
Fair Value | $ 830 | $ 766
Gross Unrealized Loss | $ (5) | $ (7)
Number of securities | security | 319 | 274
12 months or more |  |
Fair Value | $ 3,259 | $ 3,162
Gross Unrealized Loss | $ (305) | $ (281)
Number of securities | security | 1,311 | 1,266
Total |  |
Fair Value | $ 4,089 | $ 3,928
Gross Unrealized Loss | $ (310) | $ (288)
Number of securities | security | 1,609 | 1,525
Obligations of state and political subdivisions |  |
Less than 12 months |  |
Fair Value | $ 603 | $ 641
Gross Unrealized Loss | (3) | (4)
12 months or more |  |
Fair Value | 1,250 | 931
Gross Unrealized Loss | (96) | (87)
Total |  |
Fair Value | 1,853 | 1,572
Gross Unrealized Loss | (99) | (91)
U.S. government and agencies |  |
Less than 12 months |  |
Fair Value | 7 | 0
Gross Unrealized Loss | 0 | 0
12 months or more |  |
Fair Value | 33 | 33
Gross Unrealized Loss | (6) | (6)
Total |  |
Fair Value | 40 | 33
Gross Unrealized Loss | (6) | (6)
Corporate securities |  |
Less than 12 months |  |
Fair Value | 164 | 72
Gross Unrealized Loss | (2) | (1)
12 months or more |  |
Fair Value | 1,384 | 1,426
Gross Unrealized Loss | (168) | (152)
Total |  |
Fair Value | 1,548 | 1,498
Gross Unrealized Loss | (170) | (153)
RMBS |  |
Less than 12 months |  |
Fair Value | 34 | 27
Gross Unrealized Loss | 0 | (1)
12 months or more |  |
Fair Value | 138 | 124
Gross Unrealized Loss | (11) | (8)
Total |  |
Fair Value | 172 | 151
Gross Unrealized Loss | (11) | (9)
CMBS |  |
Less than 12 months |  |
Fair Value | 4 | 3
Gross Unrealized Loss | 0 | 0
12 months or more |  |
Fair Value | 127 | 148
Gross Unrealized Loss | (6) | (6)
Total |  |
Fair Value | 131 | 151
Gross Unrealized Loss | (6) | (6)
CLOs |  |
Less than 12 months |  |
Fair Value | 9 | 22
Gross Unrealized Loss | 0 | (1)
12 months or more |  |
Fair Value | 222 | 379
Gross Unrealized Loss | (2) | (6)
Total |  |
Fair Value | 231 | 401
Gross Unrealized Loss | (2) | (7)
Other |  |
Less than 12 months |  |
Fair Value | 9 | 1
Gross Unrealized Loss | 0 | 0
12 months or more |  |
Fair Value | 26 | 26
Gross Unrealized Loss | (1) | (1)
Total |  |
Fair Value | 35 | 27
Gross Unrealized Loss | (1) | (1)
Non-U.S. government securities |  |
Less than 12 months |  |
Fair Value | 0 | 0
Gross Unrealized Loss | 0 | 0
12 months or more |  |
Fair Value | 79 | 95
Gross Unrealized Loss | (15) | (15)
Total |  |
Fair Value | 79 | 95
Gross Unrealized Loss | $ (15) | $ (15)

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