Accumulated Other Comprehensive Income (Details Of The Reclassification From AOCI) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income (loss) before income taxes	$ (357)	$ (296)	$ (661)
Provision (benefit) for income taxes	2	0	944
Net income (loss)	(359)	(296)	(1,605)
Amounts reclassified from AOCI [Member]
Net income (loss)	(40)	0	(8)
Unrealized gains (losses) on AFS, net [Member]
Net income (loss)	(12)	0	(8)
Unrealized gains (losses) on AFS, net [Member] | Amounts reclassified from AOCI [Member]
Net gains (losses) on financial instruments at fair value and foreign exchange	14	6	3
Net investment losses related to OTTI	(25)	(5)	(7)
Net investment income	(1)	(1)	(5)
Income (loss) before income taxes	(12)	0	(9)
Provision (benefit) for income taxes	0	0	(1)
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	$ (28)	$ 0	$ 0