Accounting Policies (Details) - USD ($) $ in Millions	Sep. 30, 2020	Jan. 01, 2020	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Finance receivables, net	$ 104,864		$ 114,317
Other Assets	4,132	$ 3,390	3,398
Deferred Tax Liabilities, Gross	2,731	2,535	2,593
Retained Earnings (Accumulated Deficit)	9,865	9,703	9,905
Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Finance receivables, net	252
Other Assets		(8)
Deferred Tax Liabilities, Gross		(58)
Retained Earnings (Accumulated Deficit)		(202)
Retail Installment loans, dealer financing, and other financing [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Finance receivables, net	$ 97,021	105,901	106,131
Retail Installment loans, dealer financing, and other financing [Member] | Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Finance receivables, net		(230)
Finance Lease [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Finance receivables, net		8,164	$ 8,186
Finance Lease [Member] | Accounting Standards Update 2016-13 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Finance receivables, net		$ (22)