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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 | Dec. 31, 2021 | Dec. 31, 2020
--- | --- | ---
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | $ 676 | $ 325
Less than 12 months, unrealized losses | (8) | (3)
12 months or longer, fair value | 55 | 91
12 months or longer, unrealized losses | (1) | (2)
Total available-for-sale, fair value | 731 | 416
Total available-for-sale, unrealized losses | (9) | (5)
U S Treasury And Government [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 161 | 99
Less than 12 months, unrealized losses | (1) | (1)
12 months or longer, fair value | 16 | 0
12 months or longer, unrealized losses | (1) | 0
Total available-for-sale, fair value | 177 | 99
Total available-for-sale, unrealized losses | (2) | (1)
State and municipal bonds [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 11 |
Less than 12 months, unrealized losses | 0 |
12 months or longer, fair value | 0 |
12 months or longer, unrealized losses | 0 |
Total available-for-sale, fair value | 11 |
Total available-for-sale, unrealized losses | 0 |
Foreign Government Debt [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 3 | 2
Less than 12 months, unrealized losses | 0 | 0
12 months or longer, fair value | 0 | 0
12 months or longer, unrealized losses | 0 | 0
Total available-for-sale, fair value | 3 | 2
Total available-for-sale, unrealized losses | 0 | 0
Corporate Obligations [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 270 | 103
Less than 12 months, unrealized losses | (5) | (1)
12 months or longer, fair value | 8 | 7
12 months or longer, unrealized losses | 0 | 0
Total available-for-sale, fair value | 278 | 110
Total available-for-sale, unrealized losses | (5) | (1)
Residential Mortgage Backed Agency [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 94 | 53
Less than 12 months, unrealized losses | (1) | (1)
12 months or longer, fair value | 1 | 0
12 months or longer, unrealized losses | 0 | 0
Total available-for-sale, fair value | 95 | 53
Total available-for-sale, unrealized losses | (1) | (1)
Residential Mortgage Backed Non Agency [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 3 | 2
Less than 12 months, unrealized losses | 0 | 0
12 months or longer, fair value | 1 | 1
12 months or longer, unrealized losses | 0 | 0
Total available-for-sale, fair value | 4 | 3
Total available-for-sale, unrealized losses | 0 | 0
Commercial Mortgage Backed Securities [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 2 | 0
Less than 12 months, unrealized losses | 0 | 0
12 months or longer, fair value | 0 | 5
12 months or longer, unrealized losses | 0 | 0
Total available-for-sale, fair value | 2 | 5
Total available-for-sale, unrealized losses | 0 | 0
Collateralized Debt Obligations [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 60 | 37
Less than 12 months, unrealized losses | 0 | 0
12 months or longer, fair value | 29 | 78
12 months or longer, unrealized losses | 0 | (2)
Total available-for-sale, fair value | 89 | 115
Total available-for-sale, unrealized losses | 0 | (2)
Other Asset Backed [Member] |  |
Available For Sale Securities [Abstract] |  |
Less than 12 months, fair value | 72 | 29
Less than 12 months, unrealized losses | (1) | 0
12 months or longer, fair value | 0 | 0
12 months or longer, unrealized losses | 0 | 0
Total available-for-sale, fair value | 72 | 29
Total available-for-sale, unrealized losses | $ (1) | $ 0

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