Loans - Consumer, Excluding Credit Card Loan Portfolio, Loan Modifications, New TDRs (Details) - Consumer, excluding credit card - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Total residential real estate – excluding PCI
Financing Receivable, Impaired [Line Items]
New TDRs	$ 183	$ 165	$ 433	$ 318
Residential mortgage
Financing Receivable, Impaired [Line Items]
New TDRs	100	96	247	168
Home equity
Financing Receivable, Impaired [Line Items]
New TDRs	$ 83	$ 69	$ 186	$ 150