Pension and Other Postretirement Employee Benefit Plans - Plan Assumptions (Details) - U.S. - Defined benefit pension plans $ in Millions	12 Months Ended
Dec. 31, 2020 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Projected decrease in expense due to decreased discount rates	$ 64
Expected long-term rate of return on plan assets, next fiscal year	3.00%

An assumption as to the rate of return on plan assets reflecting the average rate of earnings expected on the funds invested or to be invested to provide for the benefits included in the benefit obligation for the next fiscal year.

No definition available.

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