Derivative Instruments (Effect Of Derivative Instruments On Consolidated Statements Of Operations) (Detail) (Nondesignated [Member], USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Derivative [Line Items]
Net gain/(loss) recognized in income	$ (77)	$ (137)	$ 374	$ (180)
Unrealized Gains Losses On Insured Derivatives [Member] | Credit Default Swap [Member]
Derivative [Line Items]
Net gain/(loss) recognized in income	(23)	1,318	800	1,216
Unrealized Gains Losses On Insured Derivatives [Member] | All Other [Member]
Derivative [Line Items]
Net gain/(loss) recognized in income	0	32	15	61
Unrealized Gains Losses On Insured Derivatives [Member] | Insured Swaps [Member]
Derivative [Line Items]
Net gain/(loss) recognized in income	0		0	0
Realized Gains Losses And Other Settlements On Insured Derivatives [Member] | Credit Default Swap [Member]
Derivative [Line Items]
Net gain/(loss) recognized in income	(24)	(1,532)	(363)	(1,520)
Realized Gains Losses And Other Settlements On Insured Derivatives [Member] | All Other [Member]
Derivative [Line Items]
Net gain/(loss) recognized in income	0		(30)
Foreign Exchange And Other Derivative Financial Instruments [Member] | Non Insured Credit Default Swaps [Member]
Derivative [Line Items]
Net gain/(loss) recognized in income	0	0	0	0
Foreign Exchange And Other Derivative Financial Instruments [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Net gain/(loss) recognized in income	(22)	38	(45)	41
Foreign Exchange And Other Derivative Financial Instruments [Member] | Currency Swap [Member]
Derivative [Line Items]
Net gain/(loss) recognized in income	0	0	0	2
Foreign Exchange And Other Derivative Financial Instruments [Member] | All Other [Member]
Derivative [Line Items]
Net gain/(loss) recognized in income	(2)	0	(3)	0
Foreign Exchange And Other Derivative Financial Instruments Attributable To V I E [Member] | Non Insured Credit Default Swaps V I E [Member]
Derivative [Line Items]
Net gain/(loss) recognized in income	0	0	0	0
Foreign Exchange And Other Derivative Financial Instruments Attributable To V I E [Member] | Interest Rate Swaps V I E [Member]
Derivative [Line Items]
Net gain/(loss) recognized in income	0	0	0	14
Foreign Exchange And Other Derivative Financial Instruments Attributable To V I E [Member] | Currency Swaps Vie [Member]
Derivative [Line Items]
Net gain/(loss) recognized in income	(6)	7	0	6
Foreign Exchange And Other Derivative Financial Instruments Attributable To V I E [Member] | All Other V I E [Member]
Derivative [Line Items]
Net gain/(loss) recognized in income	$ 0	$ 0		$ 0