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Investments (Gross Unrealized Losses Related To Available-For-Sale And Held-To-Maturity Investments) (Detail) - USD ($) $ in Millions | Jun. 30, 2025 | Dec. 31, 2024
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Available For Sale Securities [Abstract] |  |
Investment, Type [Extensible Enumeration] | Fixed Maturities [Member] | Fixed Maturities [Member]
Less than 12 months, fair value | $ 64 | $ 106
Less than 12 months, unrealized losses | (2) | (4)
12 months or longer, fair value | 596 | 634
12 months or longer, unrealized losses | (136) | (156)
Total, fair value | 660 | 740
Tota, unrealized losses | (138) | (160)
U.S. Treasury And Government Agency [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 14 | 41
Less than 12 months, unrealized losses | 0 | (1)
12 months or longer, fair value | 121 | 123
12 months or longer, unrealized losses | (12) | (18)
Total, fair value | 135 | 164
Tota, unrealized losses | (12) | (19)
State and municipal bonds [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 6 | 15
Less than 12 months, unrealized losses | 0 | (1)
12 months or longer, fair value | 61 | 63
12 months or longer, unrealized losses | (9) | (10)
Total, fair value | 67 | 78
Tota, unrealized losses | (9) | (11)
Foreign Governments [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 0 | 5
Less than 12 months, unrealized losses | 0 | 0
12 months or longer, fair value | 5 | 5
12 months or longer, unrealized losses | (2) | (2)
Total, fair value | 5 | 10
Tota, unrealized losses | (2) | (2)
Corporate Obligations [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 11 | 25
Less than 12 months, unrealized losses | (2) | (1)
12 months or longer, fair value | 277 | 302
12 months or longer, unrealized losses | (97) | (105)
Total, fair value | 288 | 327
Tota, unrealized losses | (99) | (106)
Residential Mortgage backed Agency [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 0 | 5
Less than 12 months, unrealized losses | 0 | 0
12 months or longer, fair value | 95 | 100
12 months or longer, unrealized losses | (13) | (16)
Total, fair value | 95 | 105
Tota, unrealized losses | (13) | (16)
Residential Mortgage Backed Non Agency [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 0 | 6
Less than 12 months, unrealized losses | 0 | (1)
12 months or longer, fair value | 6 | 21
12 months or longer, unrealized losses | (1) | (4)
Total, fair value | 6 | 27
Tota, unrealized losses | (1) | (5)
Commercial mortgage backed Securities [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 2 |
Less than 12 months, unrealized losses | 0 |
12 months or longer, fair value | 5 |
12 months or longer, unrealized losses | 0 |
Total, fair value | 7 |
Tota, unrealized losses | 0 |
Collateralized debt obligations [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 12 | 6
Less than 12 months, unrealized losses | 0 | 0
12 months or longer, fair value | 0 | 8
12 months or longer, unrealized losses | 0 | 0
Total, fair value | 12 | 14
Tota, unrealized losses | 0 | 0
Other asset backed [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 19 | 3
Less than 12 months, unrealized losses | 0 | 0
12 months or longer, fair value | 26 | 12
12 months or longer, unrealized losses | (2) | (1)
Total, fair value | 45 | 15
Tota, unrealized losses | $ (2) | $ (1)

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