Derivative Instruments - Impact on Balance Sheet (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Derivatives, Fair Value [Line Items]
Gross derivative receivables	$ 609,717	$ 707,554
Net derivative receivables	73,119	79,630
Gross derivative payables	582,697	688,887
Net derivative payables	60,440	70,623
Interest rate
Derivatives, Fair Value [Line Items]
Gross derivative receivables	311,621	391,490
Net derivative receivables	28,548	35,725
Gross derivative payables	279,186	353,627
Net derivative payables	10,744	13,012
Credit
Derivatives, Fair Value [Line Items]
Gross derivative receivables	14,212	13,503
Net derivative receivables	1,048	680
Gross derivative payables	14,602	15,192
Net derivative payables	1,898	1,995
Foreign exchange
Derivatives, Fair Value [Line Items]
Gross derivative receivables	186,627	206,260
Net derivative receivables	15,112	15,781
Gross derivative payables	185,506	215,926
Net derivative payables	17,038	21,433
Equity
Derivatives, Fair Value [Line Items]
Gross derivative receivables	73,578	74,798
Net derivative receivables	19,753	20,673
Gross derivative payables	79,543	81,413
Net derivative payables	22,400	25,898
Commodity
Derivatives, Fair Value [Line Items]
Gross derivative receivables	23,679	21,503
Net derivative receivables	8,658	6,771
Gross derivative payables	23,860	22,729
Net derivative payables	8,360	8,285
Not designated as hedges
Derivatives, Fair Value [Line Items]
Gross derivative receivables	606,389	704,898
Gross derivative payables	579,046	685,295
Not designated as hedges | Interest rate
Derivatives, Fair Value [Line Items]
Gross derivative receivables	310,838	390,659
Gross derivative payables	279,186	353,627
Not designated as hedges | Credit
Derivatives, Fair Value [Line Items]
Gross derivative receivables	14,212	13,503
Gross derivative payables	14,602	15,192
Not designated as hedges | Foreign exchange
Derivatives, Fair Value [Line Items]
Gross derivative receivables	185,672	205,359
Gross derivative payables	184,033	214,229
Not designated as hedges | Equity
Derivatives, Fair Value [Line Items]
Gross derivative receivables	73,578	74,798
Gross derivative payables	79,543	81,413
Not designated as hedges | Commodity
Derivatives, Fair Value [Line Items]
Gross derivative receivables	22,089	20,579
Gross derivative payables	21,682	20,834
Designated as hedges
Derivatives, Fair Value [Line Items]
Gross derivative receivables	3,328	2,656
Gross derivative payables	3,651	3,592
Designated as hedges | Interest rate
Derivatives, Fair Value [Line Items]
Gross derivative receivables	783	831
Gross derivative payables	0	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	955	901
Gross derivative payables	1,473	1,697
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	1,590	924
Gross derivative payables	$ 2,178	$ 1,895