Securitizations Securitizations (Narrative) (Details) (USD $) In Billions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Securtizations [Line Items]
Finance Receivables Transferred to Special Purpose Entities	$ 9.9	$ 7.9

Finance Receivables Transferred to Special Purpose Entities

No definition available.

Name:	acf_FinanceReceivablesTransferredToSpecialPurposeEntities
Namespace Prefix:	acf_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant