Derivative Instruments (Summary Of Effect Of Derivative Instruments On Consolidated Statement Of Operations) (Details) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Derivatives In Fair Value Hedging Relationships [Member]
Derivative [Line Items]
Gain (Loss) Recognized in Income on Derivative	$ (8)	$ (6)	$ (4)	$ (44)
Gain (Loss) Recognized in Income on Hedged item	8	6	4	44
Net Gain (Loss) Recognized in Income	(2)	(2)	(7)	(3)
Derivatives In Fair Value Hedging Relationships [Member] | Interest Rate Swaps [Member] | Net Gains (Losses) On Financial Instruments At Fair Value And Foreign Exchange [Member]
Derivative [Line Items]
Gain (Loss) Recognized in Income on Derivative	(8)	(4)	(6)	(45)
Gain (Loss) Recognized in Income on Hedged item	8	4	6	45
Derivatives In Fair Value Hedging Relationships [Member] | Interest Rate Swaps [Member] | Interest Income (Expense) [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income	(2)	(2)	(7)	(3)
Derivatives In Fair Value Hedging Relationships [Member] | Currency Swaps [Member]
Derivative [Line Items]
Gain (Loss) Recognized in Income on Derivative		(2)
Gain (Loss) Recognized in Income on Hedged item		2
Derivatives In Fair Value Hedging Relationships [Member] | Currency Swaps [Member] | Net Gains (Losses) On Financial Instruments At Fair Value And Foreign Exchange [Member]
Derivative [Line Items]
Gain (Loss) Recognized in Income on Derivative			2	1
Gain (Loss) Recognized in Income on Hedged item			(2)	(1)
Derivatives Not Designated As Hedging Instruments [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income	715	(643)	(1,301)	(1,660)
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps [Member] | Net Gains (Losses) On Financial Instruments At Fair Value And Foreign Exchange [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income	(128)	(60)	(178)	(184)
Derivatives Not Designated As Hedging Instruments [Member] | Currency Swaps [Member] | Net Gains (Losses) On Financial Instruments At Fair Value And Foreign Exchange [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income	4	38	(3)	2
Derivatives Not Designated As Hedging Instruments [Member] | Currency Swaps -VIE [Member] | Net Gains (Losses) On Financial Instruments At Fair Value And Foreign Exchange-VIE [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income	(2)		(4)
Derivatives Not Designated As Hedging Instruments [Member] | Insured Credit Default Swaps [Member] | Unrealized Gains (Losses) On Insured Derivatives [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income	756	(1,042)	(516)	(1,707)
Derivatives Not Designated As Hedging Instruments [Member] | Insured Credit Default Swaps [Member] | Realized Gains (Losses) And Other Settlements On Insured Derivatives [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income	(53)	552	(599)	454
Derivatives Not Designated As Hedging Instruments [Member] | Insured Swaps [Member] | Unrealized Gains (Losses) On Insured Derivatives [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income		2		2
Derivatives Not Designated As Hedging Instruments [Member] | Non-Insured Credit Default Swaps [Member] | Net Gains (Losses) On Financial Instruments At Fair Value And Foreign Exchange [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income		(1)	(1)
Derivatives Not Designated As Hedging Instruments [Member] | Non-Insured Credit Default Swaps-VIE [Member] | Net Gains (Losses) On Financial Instruments At Fair Value And Foreign Exchange-VIE [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income	154	(16)	4	(19)
Derivatives Not Designated As Hedging Instruments [Member] | Interest Rate Swaps-VIE [Member] | Net Gains (Losses) On Financial Instruments At Fair Value And Foreign Exchange-VIE [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income	(25)	(106)	24	(191)
Derivatives Not Designated As Hedging Instruments [Member] | Credit Linked Notes [Member] | Net Gains (Losses) On Financial Instruments At Fair Value And Foreign Exchange [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income				18
Derivatives Not Designated As Hedging Instruments [Member] | All Others [Member] | Net Gains (Losses) On Financial Instruments At Fair Value And Foreign Exchange [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income	(6)	(4)	(7)	(12)
Derivatives Not Designated As Hedging Instruments [Member] | All Others [Member] | Unrealized Gains (Losses) On Insured Derivatives [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income	20	(4)	(15)	(12)
Derivatives Not Designated As Hedging Instruments [Member] | All Other VIE [Member] | Net Gains (Losses) On Financial Instruments At Fair Value And Foreign Exchange-VIE [Member]
Derivative [Line Items]
Net Gain (Loss) Recognized in Income	$ (5)	$ (2)	$ (6)	$ (11)