Outstanding Loans and Leases - Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans and leases including disposal group	$ 915,747	$ 915,897
Allowance included in assets of business held for sale	242	243
Credit card and other consumer
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Allowance included in assets of business held for sale	242	243
Credit Card Receivable | Non United States | Credit card and other consumer
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans and leases including disposal group	9,505	9,214
Credit Card Receivable | Carrying Value | Non United States | Credit card and other consumer
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Loans and leases including disposal group	$ 9,505	$ 9,214