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Investments (Amortized Cost And Fair Value Of Available-For-Sale and Held-To-Maturity Investment Portfolios) (Detail) - USD ($) $ in Millions | Dec. 31, 2024 | Dec. 31, 2023
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Available For Sale Securities [Abstract] |  |
Investment, Type [Extensible Enumeration] | Fixed Maturities [Member] | Fixed Maturities [Member]
Total available-for-sale, amortized cost | $ 1,391 | $ 1,688
Allowance for Credit Losess | 0 | 0
Gross unrealized gains | 5 | 9
Gross unrealized losses | (160) | (140)
Total available-for-sale, fair value | 1,236 | 1,557
U.S. Treasury And Government Agency [Member] |  |
Available For Sale Securities [Abstract] |  |
Total available-for-sale, amortized cost | 500 | 721
Allowance for Credit Losess | 0 | 0
Gross unrealized gains | 0 | 1
Gross unrealized losses | (19) | (18)
Total available-for-sale, fair value | 481 | 704
US States And Political Subdivisions [Member] |  |
Available For Sale Securities [Abstract] |  |
Total available-for-sale, amortized cost | 110 | 128
Allowance for Credit Losess | 0 | 0
Gross unrealized gains | 2 | 3
Gross unrealized losses | (11) | (8)
Total available-for-sale, fair value | 101 | 123
Foreign Governments [Member] |  |
Available For Sale Securities [Abstract] |  |
Total available-for-sale, amortized cost | 12 | 19
Allowance for Credit Losess | 0 | 0
Gross unrealized gains | 0 | 1
Gross unrealized losses | (2) | (2)
Total available-for-sale, fair value | 10 | 18
Corporate Obligations [Member] |  |
Available For Sale Securities [Abstract] |  |
Total available-for-sale, amortized cost | 496 | 505
Allowance for Credit Losess | 0 | 0
Gross unrealized gains | 1 | 2
Gross unrealized losses | (106) | (90)
Total available-for-sale, fair value | 391 | 417
Residential Mortgage-Backed Agency [Member] |  |
Available For Sale Securities [Abstract] |  |
Total available-for-sale, amortized cost | 127 | 149
Allowance for Credit Losess | 0 | 0
Gross unrealized gains | 0 | 0
Gross unrealized losses | (16) | (14)
Total available-for-sale, fair value | 111 | 135
Residential Mortgage-Backed Non-Agency [Member] |  |
Available For Sale Securities [Abstract] |  |
Total available-for-sale, amortized cost | 36 | 31
Allowance for Credit Losess | 0 | 0
Gross unrealized gains | 1 | 1
Gross unrealized losses | (5) | (5)
Total available-for-sale, fair value | 32 | 27
Commercial Mortgage-Backed [Member] |  |
Available For Sale Securities [Abstract] |  |
Total available-for-sale, amortized cost | 7 | 13
Allowance for Credit Losess | 0 | 0
Gross unrealized gains | 0 | 0
Gross unrealized losses | 0 | 0
Total available-for-sale, fair value | 7 | 13
Collateralized Debt Obligations [Member] |  |
Available For Sale Securities [Abstract] |  |
Total available-for-sale, amortized cost | 71 | 96
Allowance for Credit Losess | 0 | 0
Gross unrealized gains | 1 | 1
Gross unrealized losses | 0 | (1)
Total available-for-sale, fair value | 72 | 96
Other Asset-Backed [Member] |  |
Available For Sale Securities [Abstract] |  |
Total available-for-sale, amortized cost | 32 | 26
Allowance for Credit Losess | 0 | 0
Gross unrealized gains | 0 | 0
Gross unrealized losses | (1) | (2)
Total available-for-sale, fair value | $ 31 | $ 24

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- Definition Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Topic 320 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 2 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org/1943274/2147481800/320-10-50-2 + Details
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