Derivative Instruments (Effect Of Derivative Instruments On Consolidated Statements Of Operations) (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Derivative [Line Items]
Net gain/(loss) recognized in income	$ 9	$ 27	$ (5)	$ 57
Insured swaps [Member]
Derivative [Line Items]
Net gain/(loss) recognized in income	0	1	0	1
Interest Rate Swap [Member]
Derivative [Line Items]
Net gain/(loss) recognized in income	10	26	1	56
Currency swaps-VIE [Member]
Derivative [Line Items]
Net gain/(loss) recognized in income	$ (1)	$ 0	$ (6)	$ 0