Finance Receivables and Loans, Net (Schedule of Sales of Financing Receivables and Loans) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, significant sales and transfers	$ 826	$ 1,348
Consumer portfolio segment | Automobile loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, significant sales and transfers	578	1,339
Consumer portfolio segment | Residential mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, significant sales and transfers	10	9
Commercial portfolio segment | Commercial loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Finance receivables and loans, significant sales and transfers	$ 238	$ 0