Loans (Period-End Balances And Various Asset Quality Attributes By Origination Vintage For The Real Estate Installment Loans) (Details) (Real Estate Installment Class [Member], USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Mar. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
R/E Installment Loans- Period End Balance	$ 2,276	$ 2,184
Avg orig FICO	737	730
Avg Refreshed FICO	729	722
Pre-2003 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
R/E Installment Loans- Period End Balance	51	75
Avg orig FICO	689	694
Avg Refreshed FICO	685	687
2003 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
R/E Installment Loans- Period End Balance	147	206
Avg orig FICO	722	724
Avg Refreshed FICO	730	732
2004 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
R/E Installment Loans- Period End Balance	91	120
Avg orig FICO	709	713
Avg Refreshed FICO	707	710
2005 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
R/E Installment Loans- Period End Balance	254	322
Avg orig FICO	720	722
Avg Refreshed FICO	713	713
2006 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
R/E Installment Loans- Period End Balance	278	353
Avg orig FICO	720	722
Avg Refreshed FICO	704	706
2007 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
R/E Installment Loans- Period End Balance	389	489
Avg orig FICO	729	731
Avg Refreshed FICO	712	715
2008 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
R/E Installment Loans- Period End Balance	144	195
Avg orig FICO	733	738
Avg Refreshed FICO	724	729
2009 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
R/E Installment Loans- Period End Balance	85	125
Avg orig FICO	750	753
Avg Refreshed FICO	748	752
2010 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
R/E Installment Loans- Period End Balance	187	215
Avg orig FICO	746	748
Avg Refreshed FICO	756	748
2011 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
R/E Installment Loans- Period End Balance	462	84
Avg orig FICO	761	755
Avg Refreshed FICO	758	754
2012 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
R/E Installment Loans- Period End Balance	$ 188
Avg orig FICO	765
Avg Refreshed FICO	767