Equity Securities (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Equity Securities [Line Items]
Equity securities, carried at fair value		$ 28,176		$ 41,936
Equity securities	[1]	54,047		68,241
Equity Securities Disclosures Textual [Abstract]
Securities held as economic hedges related to deferred compensation plan obligations		3,100		3,800
Federal Reserve Bank and Federal Home Loan Bank stock		4,500		4,800
Loss from affordable housing projects, equity method investments		339	$ 273
Affordable housing tax credits and other tax benefits, amount		398	370
Affordable housing tax credits, amount		$ 314	$ 302
Affordable housing tax credits commitment, payment period		3 years
Qualified affordable housing project investments, commitment		$ 4,200		4,300
Held for trading [Member] | Marketable equity securities [Member]
Equity Securities [Line Items]
Equity securities, carried at fair value		13,573		27,440
Not held for trading [Member]
Equity Securities [Line Items]
Equity securities, carried at fair value		14,603		14,496
Equity securities		40,474		40,801
Not held for trading [Member] | Marketable equity securities [Member]
Equity Securities [Line Items]
Equity securities, carried at fair value		7,708		6,481
Not held for trading [Member] | Nonmarketable equity securities [Member]
Equity Securities [Line Items]
Equity securities, carried at fair value		6,895		8,015
Not held for trading [Member] | Equity Method Investments [Member]
Equity Securities [Line Items]
Equity securities, not carried at fair value		19,019		19,000
Not held for trading [Member] | Low-income housing tax credit investments [Member]
Equity Securities [Line Items]
Equity securities, not carried at fair value		11,290		11,343
Not held for trading [Member] | Private equity [Member]
Equity Securities [Line Items]
Equity securities, not carried at fair value		3,351		3,459
Not held for trading [Member] | Tax-advantaged renewable energy [Member]
Equity Securities [Line Items]
Equity securities, not carried at fair value		3,991		3,811
Not held for trading [Member] | New market tax credit and other [Member]
Equity Securities [Line Items]
Equity securities, not carried at fair value		387		387
Not held for trading [Member] | Federal Reserve Bank stock and other at cost [Member]
Equity Securities [Line Items]
Equity securities, not carried at fair value		4,512		4,790
Not held for trading [Member] | Other [Member]
Equity Securities [Line Items]
Equity securities, not carried at fair value		$ 2,340		$ 2,515

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