Derivative Instruments (Effect Of Derivative Instruments On Consolidated Statements Of Operations) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Derivative [Line Items]
Net gain/(loss) recognized in income	$ 6	$ 65	$ 21
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Net Gains Losses On Financial Instruments At Fair Value And Foreign Exchange	Net Gains Losses On Financial Instruments At Fair Value And Foreign Exchange	Net Gains Losses On Financial Instruments At Fair Value And Foreign Exchange
Insured swaps [Member]
Derivative [Line Items]
Net gain/(loss) recognized in income	$ 0	$ 1	$ 0
Interest Rate Swap [Member]
Derivative [Line Items]
Net gain/(loss) recognized in income	13	79	18
Currency swaps-VIE [Member]
Derivative [Line Items]
Net gain/(loss) recognized in income	$ (7)	$ (15)	$ 3