Loans - Consumer, Excluding Credit Card Loan Portfolio, Loan Modifications, New TDRs (Details) - Consumer, excluding credit card - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Total residential real estate – excluding PCI
Financing Receivable, Impaired [Line Items]
New TDRs	$ 150	$ 122	$ 395	$ 555
Residential mortgage
Financing Receivable, Impaired [Line Items]
New TDRs	50	67	181	314
Home equity
Financing Receivable, Impaired [Line Items]
New TDRs	$ 100	$ 55	$ 214	$ 241