Transfers of Receivables - Interest Expense on Securitization Debt (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Securitization Transactions [Line Items]
Interest expense	$ 2,790	$ 3,402	$ 4,389
Securitization Transactions [Member]
Securitization Transactions [Line Items]
Interest expense	943	1,202	1,574
Securitization Transactions [Member] | Consolidated Entity Excluding Variable Interest Entities (VIE) [Member]
Securitization Transactions [Line Items]
Interest expense	114	152	201
Securitization Transactions [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Securitization Transactions [Line Items]
Interest expense	$ 829	$ 1,050	$ 1,373