Securitizations and Variable Interest Entities (Schedule of Cash Flow Received and Paid o Nonconsolidated Securitization Entities) (Details) - Consumer Portfolio Segment [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Residential Mortgage [Member]
Cash Flow Received and Paid to Nonconsolidated Securitization Entities [Line Items]
Cash Flows Between Transferor and Transferee, Proceeds from New Transfers	$ 0	$ 0	$ 0
Cash Flows Between Transferor and Transferee, Servicing Fees	0	0	0
Cash Flows Between Transferor and Transferee, Receipts on Transferor's Interest in Transferred Financial Assets, Other	0
Cash Flow Between Transferee and Transferor Representations And Warranties Obligations			(31)
Automobile Loan [Member]
Cash Flow Received and Paid to Nonconsolidated Securitization Entities [Line Items]
Cash Flows Between Transferor and Transferee, Proceeds from New Transfers	1,715	1,551	2,594
Cash Flows Between Transferor and Transferee, Servicing Fees	35	$ 28	11
Cash Flows Between Transferor and Transferee, Receipts on Transferor's Interest in Transferred Financial Assets, Other	$ 8
Cash Flow Between Transferee and Transferor Representations And Warranties Obligations			$ 0