Finance Receivables and Loans, Net Finance Receivables and Loans, Net (Schedule of Purchases of Financing Receivables and Loans) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Significant Purchases	$ 395	$ 1,370
Consumer Portfolio Segment [Member] | Automobile Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Significant Purchases	68	0
Consumer Portfolio Segment [Member] | Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, Significant Purchases	$ 327	$ 1,370