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, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables and loans, significant purchases	$ 916	$ 2,008	$ 3,149	$ 4,556
Consumer portfolio segment | Automotive loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables and loans, significant purchases	92	251	409	652
Consumer portfolio segment | Real estate-backed loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables and loans, significant purchases	811	1,743	2,724	3,890
Commercial portfolio segment | Commercial Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivables and loans, significant purchases	$ 13	$ 14	$ 16	$ 14