Summary of Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010	Dec. 31, 2009
Summary of Significant Accounting Policies [Abstract]
Number Of Days Past Due Delinquent Receivables	30
Number Of Days Past Due Unsecured Closed End Installment Loans Are Written Off	120
Number Of Days Past Due Unsecured Open Ended Revolving Loans Are Written Off	180
Number Of Days Past Due Consumer Loans Secured By Collateral Other Than Residential Real Estate Write Off	120
Number Of Days Past Due Consumer Loans Secured By Residential Real Estate Before Written Down To Fair Value Of Collateral Less Costs To Sell	360
Number Of Days Past Due Unsecured Consumer Loans In Bankruptcy Before Written Off	60
Number of Days Commercial Smaller Balance Homogeneous Loans Are Written Off	180
Incremental effect on balance sheet assets due to adopting ASU 2009 16 & 17						$ 30,572
Incremental effect on balance sheet liabilities due to adopting ASU 2009 16 & 17						32,359
Net reduction of Balance Sheet Total Equity Due to Adopting ASU 2009 16 & 17						1,787
Noncontrolling interests(c) (Note 11)	707	[1]	690	[1]	1,164	2,048
Increase Decrease In Financing Receivables	271
Troubled Debt Restructuring [Member] | Adjustments for New Accounting Pronouncement [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Allowance for Loan and Lease Losses, Period Increase (Decrease)	$ 77

[1] (c) Included accumulated other comprehensive income attributable to noncontrolling interests of $(129) million and $(141) million at December 31, 2012 and 2011, respectively.