Finance Receivables and Loans, Net (Schedule of Purchases of Financing Receivables and Loans) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables and loans, significant purchases	$ 1,587	$ 916	$ 4,937	$ 3,149
Consumer portfolio segment | Automotive loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables and loans, significant purchases	925	92	1,920	409
Consumer portfolio segment | Real estate-backed loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables and loans, significant purchases	659	811	3,013	2,724
Commercial portfolio segment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables and loans, significant purchases	$ 3	$ 13	$ 4	$ 16