Fair Value Measurements (Details 4) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Fair Value of Assets and Liabilities Measured on Non Recurring Basis
Assets, Fair Value Disclosure, Nonrecurring		$ 863		$ 863
Fair Value, Inputs, Level 2 [Member]
Fair Value of Assets and Liabilities Measured on Non Recurring Basis
Assets, Fair Value Disclosure, Nonrecurring		93		93
Fair Value, Measurements, Nonrecurring [Member]
Fair Value of Assets and Liabilities Measured on Non Recurring Basis
Assets, Fair Value Disclosure, Nonrecurring	916		916
Fair Value Assets, Measured on Non-Recurring Basis, Gain Loss Included in Revenue	(16)		(27)
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value of Assets and Liabilities Measured on Non Recurring Basis
Assets, Fair Value Disclosure, Nonrecurring	372		372
Fair Value, Measurements, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value of Assets and Liabilities Measured on Non Recurring Basis
Assets, Fair Value Disclosure, Nonrecurring	544	770	544	770
Residential Mortgage [Member]
Fair Value of Assets and Liabilities Measured on Non Recurring Basis
Assets, Fair Value Disclosure, Nonrecurring	192	286	192	286
Fair Value Assets, Measured on Non-Recurring Basis, Gain Loss Included in Revenue	(4)	(7)	(6)	(6)
Residential Mortgage [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value of Assets and Liabilities Measured on Non Recurring Basis
Assets, Fair Value Disclosure, Nonrecurring	4	38	4	38
Residential Mortgage [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value of Assets and Liabilities Measured on Non Recurring Basis
Assets, Fair Value Disclosure, Nonrecurring	188	248	188	248
Consumer Loan [Member]
Fair Value of Assets and Liabilities Measured on Non Recurring Basis
Assets, Fair Value Disclosure, Nonrecurring	67	74	67	74
Consumer Loan [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value of Assets and Liabilities Measured on Non Recurring Basis
Assets, Fair Value Disclosure, Nonrecurring	67	74	67	74
Impaired Loans [Member]
Fair Value of Assets and Liabilities Measured on Non Recurring Basis
Assets, Fair Value Disclosure, Nonrecurring	289	440	289	440
Fair Value Assets, Measured on Non-Recurring Basis, Gain Loss Included in Revenue	(12)	7	(23)	8
Impaired Loans [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value of Assets and Liabilities Measured on Non Recurring Basis
Assets, Fair Value Disclosure, Nonrecurring	289	440	289	440
Commercial Real Estate [Member]
Fair Value of Assets and Liabilities Measured on Non Recurring Basis
Assets, Fair Value Disclosure, Nonrecurring	19	42	19	42
Fair Value Assets, Measured on Non-Recurring Basis, Gain Loss Included in Revenue		1	2	(3)
Commercial Real Estate [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value of Assets and Liabilities Measured on Non Recurring Basis
Assets, Fair Value Disclosure, Nonrecurring	19	42	19	42
Capitalized Software Development Costs [Member]
Fair Value of Assets and Liabilities Measured on Non Recurring Basis
Fair Value Assets, Measured on Non-Recurring Basis, Gain Loss Included in Revenue		(16)		(94)
Building held for Sale [Member]
Fair Value of Assets and Liabilities Measured on Non Recurring Basis
Assets, Fair Value Disclosure, Nonrecurring		8		8
Fair Value Assets, Measured on Non-Recurring Basis, Gain Loss Included in Revenue		(5)		(5)
Building held for Sale [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value of Assets and Liabilities Measured on Non Recurring Basis
Assets, Fair Value Disclosure, Nonrecurring		8		8
Commercial Loan [Member]
Fair Value of Assets and Liabilities Measured on Non Recurring Basis
Assets, Fair Value Disclosure, Nonrecurring	349	13	349	13
Fair Value Assets, Measured on Non-Recurring Basis, Gain Loss Included in Revenue		(20)		(100)
Commercial Loan [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value of Assets and Liabilities Measured on Non Recurring Basis
Assets, Fair Value Disclosure, Nonrecurring	$ 349	$ 13	$ 349	$ 13