Investments (Amortized Cost And Fair Value Of Available-For-Sale and Held-To-Maturity Investment Portfolios) (Detail) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Available For Sale Securities [Abstract]
Investment, Type [Extensible Enumeration]	Fixed Maturities [Member]	Fixed Maturities [Member]
Total available-for-sale, amortized cost	$ 1,439	$ 1,464
Allowance for Credit Losess	0	0
Gross unrealized gains	5	7
Gross unrealized losses	(133)	(129)
Total available-for-sale, fair value	1,311	1,342
U.S. Treasury And Government Agency [Member] \| Fixed Maturities [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost	420	478
Allowance for Credit Losess	0	0
Gross unrealized gains	0	0
Gross unrealized losses	(11)	(10)
Total available-for-sale, fair value	409	468
US States And Political Subdivisions [Member] \| Fixed Maturities [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost	106	106
Allowance for Credit Losess	0	0
Gross unrealized gains	3	3
Gross unrealized losses	(9)	(8)
Total available-for-sale, fair value	100	101
Foreign Governments [Member] \| Fixed Maturities [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost	7	7
Allowance for Credit Losess	0	0
Gross unrealized gains	0	0
Gross unrealized losses	(2)	(2)
Total available-for-sale, fair value	5	5
Corporate Obligations [Member] \| Fixed Maturities [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost	479	462
Allowance for Credit Losess	0	0
Gross unrealized gains	0	1
Gross unrealized losses	(97)	(96)
Total available-for-sale, fair value	382	367
Residential Mortgage-Backed Agency [Member] \| Fixed Maturities [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost	114	125
Allowance for Credit Losess	0	0
Gross unrealized gains	0	0
Gross unrealized losses	(11)	(11)
Total available-for-sale, fair value	103	114
Residential Mortgage-Backed Non-Agency [Member] \| Fixed Maturities [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost	16	17
Allowance for Credit Losess	0	0
Gross unrealized gains	0	0
Gross unrealized losses	(1)	(1)
Total available-for-sale, fair value	15	16
Commercial Mortgage-Backed [Member] \| Fixed Maturities [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost		10
Allowance for Credit Losess		0
Gross unrealized gains		0
Gross unrealized losses		0
Total available-for-sale, fair value		10
Collateralized Debt Obligations [Member] \| Fixed Maturities [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost	72	30
Allowance for Credit Losess	0	0
Gross unrealized gains	1	1
Gross unrealized losses	0	0
Total available-for-sale, fair value	73	31
Other Asset-Backed [Member] \| Fixed Maturities [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost	225	229
Allowance for Credit Losess	0	0
Gross unrealized gains	1	2
Gross unrealized losses	(2)	(1)
Total available-for-sale, fair value	$ 224	$ 230

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).

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Amount, before tax, of unrealized loss 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).

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of allowance for credit loss on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Indicates type of investment. Includes, but is not limited to, common stock, preferred stock, convertible security, fixed income security, government security, option purchased, warrant, loan participation and assignment, commercial paper, bankers' acceptance, certificates of deposit, short-term security, repurchase agreement, and other investment company.

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