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Accumulated Other Comprehensive Income (Details Of The Reclassification From AOCI) (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Net gains (losses) on financial instruments at fair value and foreign exchange	$ (15)	$ 4
Net income (loss)	(62)	(86)
Amounts reclassified from AOCI [Member]
Net income (loss)	(12)	(19)
Unrealized gains (losses) on AFS, net [Member] | Amounts reclassified from AOCI [Member]
Net realized investment gains (losses)	(7)	0
Foreign currency translation [Member] | Amounts reclassified from AOCI [Member]
Net gains (losses) on financial instruments at fair value and foreign exchange	(5)	0
Instrument-specific credit risk of liabilities measured at fair value, net [Member] | Amounts reclassified from AOCI [Member]
Net gains (losses) on financial instruments at fair value and foreign exchange	$ 0	$ (19)

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