Derivative Instruments - Impact on Balance Sheet (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Gross derivative receivables	$ 556,122	$ 526,239
Net derivative receivables	52,878	54,213
Gross derivative payables	532,949	501,888
Net derivative payables	41,479	41,769
Interest rate
Derivatives, Fair Value [Line Items]
Gross derivative receivables	334,556	268,704
Net derivative receivables	26,488	23,214
Gross derivative payables	301,049	242,782
Net derivative payables	8,883	7,784
Credit
Derivatives, Fair Value [Line Items]
Gross derivative receivables	15,665	20,095
Net derivative receivables	633	612
Gross derivative payables	17,231	20,276
Net derivative payables	2,256	1,667
Foreign exchange
Derivatives, Fair Value [Line Items]
Gross derivative receivables	144,100	167,685
Net derivative receivables	10,663	13,450
Gross derivative payables	147,617	165,217
Net derivative payables	11,126	12,785
Equity
Derivatives, Fair Value [Line Items]
Gross derivative receivables	44,930	49,285
Net derivative receivables	9,205	9,946
Gross derivative payables	47,698	51,195
Net derivative payables	11,177	10,161
Commodity
Derivatives, Fair Value [Line Items]
Gross derivative receivables	16,871	20,470
Net derivative receivables	5,889	6,991
Gross derivative payables	19,354	22,418
Net derivative payables	8,037	9,372
Not designated as hedges
Derivatives, Fair Value [Line Items]
Gross derivative receivables	554,687	524,531
Gross derivative payables	532,176	500,942
Not designated as hedges | Interest rate
Derivatives, Fair Value [Line Items]
Gross derivative receivables	333,694	267,871
Gross derivative payables	301,047	242,782
Not designated as hedges | Credit
Derivatives, Fair Value [Line Items]
Gross derivative receivables	15,665	20,095
Gross derivative payables	17,231	20,276
Not designated as hedges | Foreign exchange
Derivatives, Fair Value [Line Items]
Gross derivative receivables	143,659	167,057
Gross derivative payables	146,920	164,392
Not designated as hedges | Equity
Derivatives, Fair Value [Line Items]
Gross derivative receivables	44,930	49,285
Gross derivative payables	47,698	51,195
Not designated as hedges | Commodity
Derivatives, Fair Value [Line Items]
Gross derivative receivables	16,739	20,223
Gross derivative payables	19,280	22,297
Designated as hedges
Derivatives, Fair Value [Line Items]
Gross derivative receivables	1,435	1,708
Gross derivative payables	773	946
Designated as hedges | Interest rate
Derivatives, Fair Value [Line Items]
Gross derivative receivables	862	833
Gross derivative payables	2	0
Designated as hedges | Credit
Derivatives, Fair Value [Line Items]
Gross derivative receivables	0	0
Gross derivative payables	0	0
Designated as hedges | Foreign exchange
Derivatives, Fair Value [Line Items]
Gross derivative receivables	441	628
Gross derivative payables	697	825
Designated as hedges | Equity
Derivatives, Fair Value [Line Items]
Gross derivative receivables	0	0
Gross derivative payables	0	0
Designated as hedges | Commodity
Derivatives, Fair Value [Line Items]
Gross derivative receivables	132	247
Gross derivative payables	$ 74	$ 121