Supplemental Information for the Consolidated Statements of Cash Flows - Noncash Activity (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Supplemental Cash Flow Elements [Abstract]
Subvention receivable from GM	$ 282	$ 642	$ 676
Commercial loan funding payable to GM	$ 26	$ 23	$ 74

he increase (decrease) in the subvention receivable from a related party.

No definition available.

Name:	acf_IncreaseDecreaseInRelatedPartySubventionReceivable
Namespace Prefix:	acf_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration