Investments (Schedule Of Components Of Restricted Assets) (Detail) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Investments [Line Items]
Total restricted assets	$ 17,697	$ 15,836
Asset Pledged as Collateral without Right
Investments [Line Items]
Trust funds	8,462	8,120
Deposits with U.S. regulatory authorities	2,290	2,345
Deposits with non-U.S. regulatory authorities	3,366	2,959
Assets pledged under repurchase agreements	2,753	1,527
Other pledged assets	$ 826	$ 885