Accumulated Other Comprehensive Income (Details Of The Reclassification From AOCI) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income (loss) before income taxes	$ 89	$ (45)	$ (137)	$ (287)
Net income (loss)	71	(45)	(116)	(289)
Amounts reclassified from AOCI [Member]
Net income (loss)	31	0	(6)	0
Unrealized gains (losses) on AFS, net [Member] | Amounts reclassified from AOCI [Member]
Net gains (losses) on financial instruments at fair value and foreign exchange	(7)	2	16	4
Net investment losses related to OTTI	42	(2)	5	(3)
Net investment income	(1)	0	(1)	(1)
Income (loss) before income taxes	34	0	20	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	$ (3)	$ 0	$ (26)	$ 0