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Investments (Gross Unrealized Losses Related To Available-For-Sale And Held-To-Maturity Investments) (Detail) - Fixed Maturities [Member] - USD ($) $ in Millions | Mar. 31, 2023 | Dec. 31, 2022
--- | --- | ---
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | $ 644 | $ 1,165
Less than 12 months, unrealized losses | (59) | (177)
12 months or longer, fair value | 845 | 323
12 months or longer, unrealized losses | (145) | (66)
Total, fair value | 1,489 | 1,488
Tota, unrealized losses | (204) | (243)
U.S. Treasury and government agency [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 131 | 266
Less than 12 months, unrealized losses | (9) | (34)
12 months or longer, fair value | 152 | 29
12 months or longer, unrealized losses | (18) | (4)
Total, fair value | 283 | 295
Tota, unrealized losses | (27) | (38)
State and municipal bonds [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 47 | 92
Less than 12 months, unrealized losses | (1) | (10)
12 months or longer, fair value | 28 | 1
12 months or longer, unrealized losses | (7) | (1)
Total, fair value | 75 | 93
Tota, unrealized losses | (8) | (11)
Foreign Governments [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 1 | 9
Less than 12 months, unrealized losses | 0 | (3)
12 months or longer, fair value | 9 | 0
12 months or longer, unrealized losses | (2) | 0
Total, fair value | 10 | 9
Tota, unrealized losses | (2) | (3)
Corporate Obligations [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 301 | 508
Less than 12 months, unrealized losses | (40) | (106)
12 months or longer, fair value | 390 | 141
12 months or longer, unrealized losses | (89) | (42)
Total, fair value | 691 | 649
Tota, unrealized losses | (129) | (148)
Residential Mortgage backed Agency [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 60 | 112
Less than 12 months, unrealized losses | (3) | (9)
12 months or longer, fair value | 114 | 65
12 months or longer, unrealized losses | (17) | (13)
Total, fair value | 174 | 177
Tota, unrealized losses | (20) | (22)
Residential Mortgage backed Non Agency [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 51 | 65
Less than 12 months, unrealized losses | (5) | (10)
12 months or longer, fair value | 23 | 2
12 months or longer, unrealized losses | (5) | (1)
Total, fair value | 74 | 67
Tota, unrealized losses | (10) | (11)
Commercial mortgage backed Securities [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 19 | 18
Less than 12 months, unrealized losses | 0 | (1)
12 months or longer, fair value | 7 | 1
12 months or longer, unrealized losses | (1) | 0
Total, fair value | 26 | 19
Tota, unrealized losses | (1) | (1)
Collateralized debt obligations [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 25 | 51
Less than 12 months, unrealized losses | (1) | (1)
12 months or longer, fair value | 85 | 60
12 months or longer, unrealized losses | (3) | (4)
Total, fair value | 110 | 111
Tota, unrealized losses | (4) | (5)
Other asset backed [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 9 | 44
Less than 12 months, unrealized losses | 0 | (3)
12 months or longer, fair value | 37 | 24
12 months or longer, unrealized losses | (3) | (1)
Total, fair value | 46 | 68
Tota, unrealized losses | $ (3) | $ (4)

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