Goodwill Narrative (Details) (USD $) In Millions, unless otherwise specified			12 Months Ended		12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011 FinanciaLinx Corporation [Member]	Mar. 31, 2011 FinanciaLinx Corporation [Member]	Dec. 31, 2013 Ally Financial International Operations [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred			$ 10		$ 3,300
Goodwill	$ 1,240	$ 1,108		$ 14	$ 132