Equity Securities (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Equity Securities [Line Items]
Equity securities, carried at fair value		$ 35,950		$ 35,950		$ 29,556
Equity securities (includes $35,950 and $29,556 carried at fair value) (1)	[1]	61,537		61,537		55,148
Equity Securities Disclosures Textual [Abstract]
Securities held as economic hedges related to deferred compensation plan obligations		3,500		3,500		3,200
Federal home loan bank stock and federal reserve bank stock		5,600		5,600		5,600
Loss from Affordable Housing Projects, Equity Method Investments		298	$ 287	571	$ 567
Affordable Housing Tax Credits and Other Tax Benefits, Amount		376	352	746	711
Affordable Housing Tax Credits, Amount		303	$ 281	605	$ 571
Qualified Affordable Housing Project Investments, Commitment		3,900		$ 3,900		3,600
Affordable Housing Tax Credits Commitment, Payment Period				3 years
Held for trading [Member] | Marketable equity securities [Member]
Equity Securities [Line Items]
Equity securities, carried at fair value		23,327		$ 23,327		19,449
Not held for trading [Member]
Equity Securities [Line Items]
Equity securities, carried at fair value		12,623		12,623		10,107
Equity securities (includes $35,950 and $29,556 carried at fair value) (1)		38,210		38,210		35,699
Not held for trading [Member] | Marketable equity securities [Member]
Equity Securities [Line Items]
Equity securities, carried at fair value		5,379		5,379		4,513
Not held for trading [Member] | Nonmarketable equity securities [Member]
Equity Securities [Line Items]
Equity securities, carried at fair value		7,244		7,244		5,594
Not held for trading [Member] | Equity Method Investments [Member]
Equity Securities [Line Items]
Equity securities, not carried at fair value		17,859		17,859		18,215
Not held for trading [Member] | Low income housing tax credit equity method investments [Member]
Equity Securities [Line Items]
Equity securities, not carried at fair value		11,162		11,162		10,999
Not held for trading [Member] | Private equity funds [Member]
Equity Securities [Line Items]
Equity securities, not carried at fair value		3,352		3,352		3,832
Not held for trading [Member] | Tax advantaged renewable energy [Member]
Equity Securities [Line Items]
Equity securities, not carried at fair value		3,051		3,051		3,073
Not held for trading [Member] | New market tax credit and other [Member]
Equity Securities [Line Items]
Equity securities, not carried at fair value		294		294		311
Not held for trading [Member] | Investment in federal reserve bank stock and other at cost [Member]
Equity Securities [Line Items]
Equity securities, not carried at fair value		5,622		5,622		5,643
Not held for trading [Member] | Private equity [Member]
Equity Securities [Line Items]
Equity securities, not carried at fair value		$ 2,106		$ 2,106		$ 1,734

[1] (1) Parenthetical amounts represent assets and liabilities that we are required to carry at fair value or have elected the fair value option.