Securitizations and Variable Interest Entities (Schedule of Cash Flow Received from and Paid to Nonconsolidated Securitization Entities) (Details) - Off-balance sheet variable interest entities - Consumer Automotive Industry Sector - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash Flow Received and Paid to Nonconsolidated Securitization Entities [Line Items]
Cash flows received on retained interests in securitization entities	$ 11	$ 18
Cash flows between transferor and transferee, servicing fees	3	8
Cash flows between transferor and transferee, disbursement for repurchases during the period	$ (2)	$ (2)