Pension and Other Postretirement Employee Benefit Plans - Gains and Losses (Details) - Defined benefit pension plans	12 Months Ended
Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Percent above which amortization of net gains and losses is included in annual net periodic benefit cost	10.00%
U.S.
Defined Benefit Plan Disclosure [Line Items]
Average expected lifetime of plan participants	37 years

For a defined benefit plan, the percent above which amortization of net gains and losses is included in annual net periodic benefit cost

No definition available.

Name:	jpm_DefinedBenefitPlanPercentAboveWhichAmortizationOfNetGainsAndLossesIsIncludedInAnnualNetPeriodicBenefitCost
Namespace Prefix:	jpm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration