Finance Receivables And Loans, Net (Schedule of Accounts, Notes, Loans and Financing Receivables) (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans at fair value	$ 0	$ 835
Finance receivables and loans, net	119,913	114,755
Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums		221
Consumer Loans Auto Financing Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	68,136	63,459
First Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	7,030	6,891
Home Equity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	2,793	3,102
Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	9,823	9,993
Commercial And Industrial Automobile [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	35,847	34,817
Commercial And Industrial Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	1,146	1,911
Commercial And Industrial Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	2,435	1,241
Commercial Real Estate Automobile [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	2,526	2,485
Commercial Real Estate Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0	14
Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	41,954	40,468
Domestic [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans at fair value	0	603
Finance receivables and loans, net	94,505	89,096
Domestic [Member] | Consumer Loans Auto Financing Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	50,697	46,576
Domestic [Member] | First Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	7,030	6,867
Domestic [Member] | Home Equity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	2,793	3,102
Domestic [Member] | Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	9,823	9,969
Domestic [Member] | Commercial And Industrial Automobile [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	28,061	26,552
Domestic [Member] | Commercial And Industrial Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	1,146	1,887
Domestic [Member] | Commercial And Industrial Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	2,391	1,178
Domestic [Member] | Commercial Real Estate Automobile [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	2,387	2,331
Domestic [Member] | Commercial Real Estate Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0	0
Domestic [Member] | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	33,985	31,948
Foreign [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans at fair value	0	232
Finance receivables and loans, net	25,408	25,659
Foreign [Member] | Consumer Loans Auto Financing Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	17,439	16,883
Foreign [Member] | First Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0	24
Foreign [Member] | Home Equity [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0	0
Foreign [Member] | Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0	24
Foreign [Member] | Commercial And Industrial Automobile [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	7,786	8,265
Foreign [Member] | Commercial And Industrial Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0	24
Foreign [Member] | Commercial And Industrial Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	44	63
Foreign [Member] | Commercial Real Estate Automobile [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	139	154
Foreign [Member] | Commercial Real Estate Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	0	14
Foreign [Member] | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, net	7,969	8,520
loans held-for-investment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums	$ 3,000	$ 2,900