Goodwill and Mortgage Servicing Rights - Key Economic Assumptions (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Weighted-average prepayment speed assumption (constant prepayment rate)	14.90%	11.67%
Impact on fair value of 10% adverse change	$ (206)	$ (200)
Impact on fair value of 20% adverse change	$ (392)	$ (384)
Weighted-average option adjusted spread	7.19%	7.93%
Impact on fair value of 100 basis points adverse change	$ (134)	$ (169)
Impact on fair value of 200 basis points adverse change	$ (258)	$ (326)

Weighted-average option adjusted spread.

No definition available.

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

- Definition

Impact on fair value of 100 basis points adverse change in the weighted-average option adjusted spread.

+ References

No definition available.

+ Details

Name:	jpm_WeightedAverageOptionAdjustedSpreadImpactOnFairValueOfHundredBasisPointsAdverseChange
Namespace Prefix:	jpm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Impact on fair value of 200 basis points adverse change in the weighted-average option adjusted spread.

+ References

No definition available.

+ Details

Name:	jpm_WeightedAverageOptionAdjustedSpreadImpactOnFairValueOfTwoHundredBasisPointsAdverseChange
Namespace Prefix:	jpm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The hypothetical financial impact of a 10 percent adverse change of prepayment speed on the fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719

+ Details

Name:	us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOf10PercentAdverseChangeInPrepaymentSpeed
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The hypothetical financial impact of a 20 percent adverse change of prepayment speed on the fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities) as of the balance sheet date.

+ References

+ Details

Name:	us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOf20PercentAdverseChangeInPrepaymentSpeed
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

A specified percentage variance in the prepayment speed assumption in the determination of fair value of transferor's interests in transferred financial assets (including any servicing assets or servicing liabilities).

+ References

+ Details

Name:	us-gaap_SensitivityAnalysisOfFairValueOfInterestsContinuedToBeHeldByTransferorServicingAssetsOrLiabilitiesImpactOfOtherThan10Or20PercentAdverseChangeInPrepaymentSpeedPercent
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration