Loans Held-for-Sale, Net Loans Held-for-Sale, Net (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held-for-sale, net	$ 1,438	$ 2,003
Consumer Loans Auto Financing Receivable [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held-for-sale, net	1,356	1,515
Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held-for-sale, net	46	452
Commercial And Industrial Other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held-for-sale, net	$ 36	$ 36