Allowance for Credit Losses (Schedule of Information Regarding Impaired Loans) (Details) (USD $) In Millions, unless otherwise specified						12 Months Ended				12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended			12 Months Ended				12 Months Ended				12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended		12 Months Ended				12 Months Ended		12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2011 Government Guaranteed Loans [Member]	Dec. 31, 2010 Government Guaranteed Loans [Member]	Dec. 31, 2011 Impaired Loans Excluding Acquired Impaired And Government Guaranteed Loans [Member]		Dec. 31, 2010 Impaired Loans Excluding Acquired Impaired And Government Guaranteed Loans [Member]		Dec. 31, 2011 With No Related Allowance Recorded [Member] Commercial and Industrial [Member]	Dec. 31, 2010 With No Related Allowance Recorded [Member] Commercial and Industrial [Member]	Dec. 31, 2011 With No Related Allowance Recorded [Member] Commercial Real Estate - Other [Member]	Dec. 31, 2010 With No Related Allowance Recorded [Member] Commercial Real Estate - Other [Member]	Dec. 31, 2011 With No Related Allowance Recorded [Member] Commercial Real Estate - Residential ADC [Member]	Dec. 31, 2010 With No Related Allowance Recorded [Member] Commercial Real Estate - Residential ADC [Member]	Dec. 31, 2011 With No Related Allowance Recorded [Member] Commercial Other Lending Subsidiaries	Dec. 31, 2011 With No Related Allowance Recorded [Member] Direct Retail Lending [Member]	Dec. 31, 2010 With No Related Allowance Recorded [Member] Direct Retail Lending [Member]	Dec. 31, 2011 With No Related Allowance Recorded [Member] Retail Residential Mortgage [Member]		Dec. 31, 2010 With No Related Allowance Recorded [Member] Retail Residential Mortgage [Member]		Dec. 31, 2011 With No Related Allowance Recorded [Member] Retail Sales Finance [Member]	Dec. 31, 2011 With No Related Allowance Recorded [Member] Retail Other Lending Subsidiaries [Member]	Dec. 31, 2011 With A Related Allowance Recorded [Member] Commercial and Industrial [Member]	Dec. 31, 2010 With A Related Allowance Recorded [Member] Commercial and Industrial [Member]	Dec. 31, 2011 With A Related Allowance Recorded [Member] Commercial Real Estate - Other [Member]	Dec. 31, 2010 With A Related Allowance Recorded [Member] Commercial Real Estate - Other [Member]	Dec. 31, 2011 With A Related Allowance Recorded [Member] Commercial Real Estate - Residential ADC [Member]	Dec. 31, 2010 With A Related Allowance Recorded [Member] Commercial Real Estate - Residential ADC [Member]	Dec. 31, 2011 With A Related Allowance Recorded [Member] Commercial Other Lending Subsidiaries	Dec. 31, 2010 With A Related Allowance Recorded [Member] Commercial Other Lending Subsidiaries	Dec. 31, 2011 With A Related Allowance Recorded [Member] Direct Retail Lending [Member]	Dec. 31, 2010 With A Related Allowance Recorded [Member] Direct Retail Lending [Member]	Dec. 31, 2011 With A Related Allowance Recorded [Member] Retail Revolving Credit [Member]	Dec. 31, 2010 With A Related Allowance Recorded [Member] Retail Revolving Credit [Member]	Dec. 31, 2011 With A Related Allowance Recorded [Member] Retail Residential Mortgage [Member]		Dec. 31, 2010 With A Related Allowance Recorded [Member] Retail Residential Mortgage [Member]		Dec. 31, 2011 With A Related Allowance Recorded [Member] Retail Sales Finance [Member]	Dec. 31, 2010 With A Related Allowance Recorded [Member] Retail Sales Finance [Member]	Dec. 31, 2011 With A Related Allowance Recorded [Member] Retail Other Lending Subsidiaries [Member]	Dec. 31, 2010 With A Related Allowance Recorded [Member] Retail Other Lending Subsidiaries [Member]
Recorded Investment				$ 232	$ 115	$ 2,577	[1]	$ 3,043	[1]	$ 114	$ 196	$ 102	$ 175	$ 153	$ 200	$ 0	$ 19	$ 22	$ 46	[1]	$ 25	[1]	$ 1	$ 2	$ 542	$ 512	$ 409	$ 516	$ 267	$ 484	$ 5	$ 4	$ 146	$ 155	$ 62	$ 62	$ 653	[1]	$ 663	[1]	$ 9	$ 5	$ 47	$ 24
Unpaid Principal Balance						3,048	[1]	3,532	[1]	196	267	163	246	289	300	0	74	69	85	[1]	50	[1]	1	4	552	534	433	565	298	556	5	4	153	161	61	61	674	[1]	690	[1]	10	5	50	24
Related Allowance	2,256	2,708	2,600	27	14	405	[1]	442	[1]																77	96	69	63	50	75	1	1	35	26	27	25	125	[1]	153	[1]	1	1	20	2
Average Recorded Investment						1,958	[1]			102		94		145		0	23		55	[1]			1	3	300		278		164		5		128		61		562	[1]			6		31
Interest Income Recognized						$ 50	[1]			$ 0		$ 1		$ 0		$ 0	$ 1		$ 2	[1]			$ 0	$ 0	$ 1		$ 5		$ 1		$ 0		$ 8		$ 3		$ 26	[1]			$ 0		$ 2

[1] Residential mortgage loans exclude $232 million and $115 million in government guaranteed loans and related allowance of $27 million and $14 million as of December 31, 2011 and December 31, 2010, respectively.