Derivative Instruments - Impact on Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Derivatives, Fair Value [Line Items]
Gross derivative receivables	$ 707,554	$ 529,626
Net derivative receivables	79,630	49,766
Gross derivative payables	688,887	512,128
Net derivative payables	70,623	43,708
Interest rate
Derivatives, Fair Value [Line Items]
Gross derivative receivables	391,490	313,294
Net derivative receivables	35,725	27,421
Gross derivative payables	353,627	279,273
Net derivative payables	13,012	8,603
Credit
Derivatives, Fair Value [Line Items]
Gross derivative receivables	13,503	14,876
Net derivative receivables	680	701
Gross derivative payables	15,192	15,121
Net derivative payables	1,995	1,652
Foreign exchange
Derivatives, Fair Value [Line Items]
Gross derivative receivables	206,260	138,487
Net derivative receivables	15,781	9,005
Gross derivative payables	215,926	145,108
Net derivative payables	21,433	13,158
Equity
Derivatives, Fair Value [Line Items]
Gross derivative receivables	74,798	45,727
Net derivative receivables	20,673	6,477
Gross derivative payables	81,413	52,741
Net derivative payables	25,898	12,537
Commodity
Derivatives, Fair Value [Line Items]
Gross derivative receivables	21,503	17,242
Net derivative receivables	6,771	6,162
Gross derivative payables	22,729	19,885
Net derivative payables	8,285	7,758
Not designated as hedges
Derivatives, Fair Value [Line Items]
Gross derivative receivables	704,898	528,147
Gross derivative payables	685,295	510,995
Not designated as hedges | Interest rate
Derivatives, Fair Value [Line Items]
Gross derivative receivables	390,659	312,451
Gross derivative payables	353,627	279,272
Not designated as hedges | Credit
Derivatives, Fair Value [Line Items]
Gross derivative receivables	13,503	14,876
Gross derivative payables	15,192	15,121
Not designated as hedges | Foreign exchange
Derivatives, Fair Value [Line Items]
Gross derivative receivables	205,359	138,179
Gross derivative payables	214,229	144,125
Not designated as hedges | Equity
Derivatives, Fair Value [Line Items]
Gross derivative receivables	74,798	45,727
Gross derivative payables	81,413	52,741
Not designated as hedges | Commodity
Derivatives, Fair Value [Line Items]
Gross derivative receivables	20,579	16,914
Gross derivative payables	20,834	19,736
Designated as hedges
Derivatives, Fair Value [Line Items]
Gross derivative receivables	2,656	1,479
Gross derivative payables	3,592	1,133
Designated as hedges | Interest rate
Derivatives, Fair Value [Line Items]
Gross derivative receivables	831	843
Gross derivative payables	0	1
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	901	308
Gross derivative payables	1,697	983
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	924	328
Gross derivative payables	$ 1,895	$ 149