Interest and dividends on SAFS (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Debt Securities, Available-for-sale [Line Items]
Interest Income, Securities, Taxable		$ 830	$ 743	$ 630
Interest Income, Securities, Tax Exempt		19	13	6
Interest and Dividend Income, Securities, Available-for-sale	[1],[2]	$ 849	$ 756	$ 636

[1] Beginning January 1, 2018, the Company reclassified equity securities previously presented in Securities AFS to Other assets on the Consolidated Balance Sheets and began presenting income associated with certain of these equity securities in Trading account interest and other. For periods prior to January 1, 2018, this income was previously presented in Interest on securities available for sale and has been reclassified to Trading account interest and other for comparability.

[2] Beginning January 1, 2018, the Company reclassified equity securities previously presented in Securities AFS to Other assets on the Consolidated Balance Sheets and began presenting income associated with certain of these equity securities in Trading account interest and other on the Consolidated Statements of Income. For periods prior to January 1, 2018, this income was previously presented in Interest on securities available for sale and has been reclassified to Trading account interest and other for comparability.