Fair Value Of Financial Instruments (Schedule Of Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2012		Dec. 31, 2011		Mar. 31, 2011	Dec. 31, 2010
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	$ 60,810		$ 38,759
Mortgage servicing rights	95		93		144	141
Derivative receivables	1,678	[1],[2]	1,936	[1],[2]
Retained interests in securitizations and other	140		145
Total Assets	62,723		40,933
Derivatives	(490)	[1],[2]	(987)	[1],[2]
Total Liabilities	(504)		(999)
Fair value of financial guarantees	3		4
Cumulative credit risk valuation adjustment related to derivative positions	19		23
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	2,326		403
Mortgage servicing rights	0		0
Derivative receivables	1	[1],[2]	5	[1],[2]
Retained interests in securitizations and other	0		0
Total Assets	2,327		408
Derivatives	(3)	[1],[2]	(6)	[1],[2]
Total Liabilities	(3)		(6)
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	56,028		37,843
Mortgage servicing rights	0		0
Derivative receivables	1,612	[1],[2]	1,828	[1],[2]
Retained interests in securitizations and other	0		0
Total Assets	57,640		39,671
Derivatives	(451)	[1],[2]	(702)	[1],[2]
Total Liabilities	(451)		(702)
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	2,456		513
Mortgage servicing rights	95		93
Derivative receivables	65	[1],[2]	103	[1],[2]
Retained interests in securitizations and other	140		145
Total Assets	2,756		854
Derivatives	(36)	[1],[2]	(279)	[1],[2]
Total Liabilities	(50)		(291)
U.S. Treasury Debt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	2,053		124
U.S. Treasury Debt Obligations [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	2,053		124
U.S. Treasury Debt Obligations [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0		0
U.S. Treasury Debt Obligations [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0		0
US Agency Debt Obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	179		138
US Agency Debt Obligations [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0		0
US Agency Debt Obligations [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	179		138
US Agency Debt Obligations [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0		0
Residential Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	41,206		26,650
Residential Mortgage-Backed Securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0		0
Residential Mortgage-Backed Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	39,385		26,455
Residential Mortgage-Backed Securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	1,821		195
Asset-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	10,239		10,150
Asset-Backed Securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0		0
Asset-Backed Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	9,998		10,118
Asset-Backed Securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	241		32
Commercial Mortgage-Backed Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	5,585		1,187
Commercial Mortgage-Backed Securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	0		0
Commercial Mortgage-Backed Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	5,198		913
Commercial Mortgage-Backed Securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	387		274
Other Debt Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	1,548		510
Derivatives	(14)	[3]	(12)	[3]
Other Debt Securities [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	273		279
Derivatives	0	[3]	0	[3]
Other Debt Securities [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	1,268		219
Derivatives	0	[3]	0	[3]
Other Debt Securities [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Securities available for sale	7		12
Derivatives	$ (14)	[3]	$ (12)	[3]

[1] We do not offset the fair value of derivative contracts in a loss position against the fair value of contracts in a gain position. We also do not offset fair value amounts recognized for derivative instruments and fair value amounts recognized for the right to reclaim cash collateral or the obligation to return cash collateral arising from derivative instruments executed with the same counterparty under a master netting arrangement.

[2] Does not reflect $19 million and $23 million recognized as a net valuation allowance on derivative assets and liabilities for non-performance risk as of March 31, 2012 and December 31, 2011, respectively. Non-performance risk is reflected in other assets/liabilities on the balance sheet and offset through the income statement in other income.

[3] Includes manufactured housing, swap and other transactions. See "Note 7—Variable Interest Entities and Securitizations" for additional information.