GM Financial Receivables, net Consumer Finance Receivables Delinquencies and TDRs (Details) (GM Financial [Member], Consumer Finance Receivable [Member], USD $) In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
GM Financial [Member] | Consumer Finance Receivable [Member]
Delinquent Contracts [Abstract]
31 to 60 Days Past Due	$ 1,083	$ 952
Greater than 60 Days Past Due	432	408
Total Finance Receivables More Than 30 Days Delinquent	1,515	1,360
In Repossession	40	41
Total Finance Receivables More Than 30 Days Delinquent or in Repossession	1,555	1,401
31 To 60 Days Past Due, Percent Of Contractual Amount Due	4.20%	4.10%
Greater than 60 Days Past Due, Percent of Contractual Amount Due	1.70%	1.70%
Total Finance Receivables More than 30 Days Past Due, Percent of Contractual Amount Due	5.90%	5.80%
In Repossession, Percent of Contractual Amount Due	0.20%	0.20%
Total Finance Receivables More Than 30 Days Delinquent or in Repossession, Percent of Contractual Amount Due	6.10%	6.00%
Outstanding recorded investment	1,234	767
Less: allowance for loan losses	(172)	(103)
Outstanding recorded investment, net of allowance	1,062	664
Unpaid principal balance	$ 1,255	$ 779