Accumulated Other Comprehensive Income (Details Of The Reclassification From AOCI) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Net gains (losses) on financial instruments at fair value and foreign exchange	$ 21	$ 25	$ 20	$ 51
Net income (loss)	(185)	(34)	(353)	(143)
Amounts reclassified from AOCI [Member]
Net income (loss)	(14)	(20)	(61)	(6)
Unrealized gains (losses) on AFS, net [Member] | Amounts reclassified from AOCI [Member]
Net realized investment gains (losses)	(3)	3	(16)	5
Instrument-specific credit risk of liabilities measured at fair value, net [Member] | Amounts reclassified from AOCI [Member]
Other net realized gains (losses)	1	0	(20)	0
Net gains (losses) on financial instruments at fair value and foreign exchange	$ (12)	$ (23)	$ (25)	$ (11)