Accumulated Other Comprehensive Income (Details Of The Reclassification From AOCI) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Net gains (losses) on financial instruments at fair value and foreign exchange	$ (55)	$ 57	$ 20	$ 63
Income (loss) before income taxes	(55)	148	150	607
Provision (benefit) for income taxes	(20)	(25)	52	58
Net income (loss)	(35)	173	98	549
Amounts reclassified from AOCI [Member]
Net income (loss)	(7)	0	(9)	(18)
Unrealized gains (losses) on AFS, net [Member] | Amounts reclassified from AOCI [Member]
Net gains (losses) on financial instruments at fair value and foreign exchange	(5)	0	(6)	(20)
Other-than-temporary impairments recognized in accumulated other comprehensive income (loss)	(3)	0	(3)	0
Net investment income	(1)	0	(4)	(2)
Income (loss) before income taxes	(9)	0	(13)	(22)
Provision (benefit) for income taxes	(2)	0	(4)	(8)
Net income (loss)	(7)	0	(9)	(14)
Foreign currency translation, net [Member] | Amounts reclassified from AOCI [Member]
Net gains (losses) on financial instruments at fair value and foreign exchange	$ 0	$ 0	$ 0	$ (4)