Accumulated Other Comprehensive Income (Details Of The Reclassification From AOCI) (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net gains (losses) on financial instruments at fair value and foreign exchange	$ 5	$ 7	$ 62	$ (18)
Income (loss) before income taxes	171	(57)	122	759
Provision (benefit) for income taxes	39	(64)	4	161
Net income (loss)	132	7	118	598
Unrealized gains (losses) on AFS, net [Member] | Amounts reclassified from AOCI [Member]
Net gains (losses) on financial instruments at fair value and foreign exchange			15
Net investment income			(4)
Income (loss) before income taxes			11
Provision (benefit) for income taxes			4
Net income (loss)			$ 7