Investment Securities (Investment Income) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Taxable interest	$ 690	$ 534	$ 375
Taxable dividends	14	12	17
Interest and dividends exempt from U.S. federal income tax	25	22	19
Interest and dividends on investment securities	788	599	418
Excludes other earning assets
Interest and dividends on investment securities	$ 729	$ 568	$ 411

Amount of operating interest income, including amortization and accretion of premiums and discounts, on securities subject to state, federal and other income tax.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 220
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.2)
-URI http://asc.fasb.org/extlink&oid=114873765&loc=SL114874048-224260

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