Investments (Distribution By Contractual Maturity Of 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]
Due in one year or less	$ 218
Due after one year through five years	419
Due after five years through ten years	341
Due after ten years	752
Mortgage-backed and asset-backed	570
Total fixed-maturity investments	2,300
Due in one year or less	218
Due after one year through five years	411
Due after five years through ten years	302
Due after ten years	648
Mortgage-backed and asset-backed	537
Total fixed-maturity investments	$ 2,116	$ 1,931