Investments (Amortized Cost And Fair Value Of Available-For-Sale and Held-To-Maturity Investment Portfolios) (Detail) - Fixed Maturities [Member] - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost	$ 2,627	$ 2,316
Allowance for Credit Losess	(3)	0
Gross unrealized gains	28	150
Gross unrealized losses	(187)	(9)
Total available-for-sale, fair value	2,465	2,457
U S Treasury And Government [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost	716	782
Allowance for Credit Losess	0	0
Gross unrealized gains	15	54
Gross unrealized losses	(30)	(2)
Total available-for-sale, fair value	701	834
US States And Political Subdivisions [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost	353	140
Allowance for Credit Losess	0	0
Gross unrealized gains	7	27
Gross unrealized losses	(7)	0
Total available-for-sale, fair value	353	167
Foreign Governments [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost	21	13
Allowance for Credit Losess	0	0
Gross unrealized gains	0	1
Gross unrealized losses	(4)	0
Total available-for-sale, fair value	17	14
Corporate Obligations [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost	909	905
Allowance for Credit Losess	(3)	0
Gross unrealized gains	2	53
Gross unrealized losses	(112)	(5)
Total available-for-sale, fair value	796	953
Residential Mortgage-Backed Agency [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost	205	190
Allowance for Credit Losess	0	0
Gross unrealized gains	0	3
Gross unrealized losses	(14)	(1)
Total available-for-sale, fair value	191	192
Residential Mortgage-Backed Non-Agency [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost	144	80
Allowance for Credit Losess	0	0
Gross unrealized gains	4	12
Gross unrealized losses	(11)	0
Total available-for-sale, fair value	137	92
Commercial Mortgage-Backed [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost	17	10
Allowance for Credit Losess	0	0
Gross unrealized gains	0	0
Gross unrealized losses	(1)	0
Total available-for-sale, fair value	16	10
Collateralized Debt Obligations [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost	122	101
Allowance for Credit Losess	0	0
Gross unrealized gains	0	0
Gross unrealized losses	(5)	0
Total available-for-sale, fair value	117	101
Other Asset-Backed [Member]
Available For Sale Securities [Abstract]
Total available-for-sale, amortized cost	140	95
Allowance for Credit Losess	0	0
Gross unrealized gains	0	0
Gross unrealized losses	(3)	(1)
Total available-for-sale, fair value	$ 137	$ 94

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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