Finance Receivables, Net Credit Quality (Details) (Consumer Loans Auto Financing Receivable [Member], GM Financial [Member], USD $) In Millions, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Financing Receivable, Recorded Investment [Line Items]
Finance Receivables, Carrying Value	$ 10,440	$ 9,680
FICO Scores Less Than 540 [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance Receivables, Carrying Value	2,631	2,133
FICO score 540 to 599 [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance Receivables, Carrying Value	4,632	4,167
FICO score 600 to 659 [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance Receivables, Carrying Value	2,582	2,624
FICO score greater than 660 [Member]
Financing Receivable, Recorded Investment [Line Items]
Finance Receivables, Carrying Value	$ 595	$ 756