Variable Interest Entities - Firm Sponsored Variable Interest Entities (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Firm-sponsored mortgage and other consumer securitization trusts
Total assets held by securitization VIEs	$ 182,272	$ 186,912
Retained securitization interests, risk-rated 'A' or better, at fair value	73.00%	63.00%
Corporate & Investment Bank
Firm-sponsored mortgage and other consumer securitization trusts
Senior securities purchased in connection with CIB's secondary market-making activities	$ 105	$ 106
Subordinated securities purchased in connection with CIB's secondary market-making activities	40	94
Residential mortgage \| Investment-grade
Firm-sponsored mortgage and other consumer securitization trusts
Fair value of retained interests	1,300	1,100
Residential mortgage \| Noninvestment-grade
Firm-sponsored mortgage and other consumer securitization trusts
Fair value of retained interests	41	72
Residential mortgage \| Prime/Alt-A and option ARMs
Firm-sponsored mortgage and other consumer securitization trusts
Total assets held by securitization VIEs	49,644	60,348
Residential mortgage \| Subprime
Firm-sponsored mortgage and other consumer securitization trusts
Total assets held by securitization VIEs	12,896	14,661
Commercial and other
Firm-sponsored mortgage and other consumer securitization trusts
Total assets held by securitization VIEs	119,732	111,903
Commercial and other \| Investment-grade
Firm-sponsored mortgage and other consumer securitization trusts
Fair value of retained interests	2,000	1,200
Commercial and other \| Noninvestment-grade
Firm-sponsored mortgage and other consumer securitization trusts
Fair value of retained interests	753	575
VIEs consolidated by the Firm
Firm-sponsored mortgage and other consumer securitization trusts
Assets held in consolidated securitization VIEs	1,739	2,796
VIEs consolidated by the Firm \| Residential mortgage \| Prime/Alt-A and option ARMs
Firm-sponsored mortgage and other consumer securitization trusts
Assets held in consolidated securitization VIEs	1,693	2,796
VIEs consolidated by the Firm \| Residential mortgage \| Subprime
Firm-sponsored mortgage and other consumer securitization trusts
Assets held in consolidated securitization VIEs	46	0
VIEs consolidated by the Firm \| Commercial and other
Firm-sponsored mortgage and other consumer securitization trusts
Assets held in consolidated securitization VIEs	0	0
Nonconsolidated entities
Firm-sponsored mortgage and other consumer securitization trusts
Assets held in nonconsolidated securitization VIEs with continuing involvement	145,770	143,102
Interest in securitized assets in nonconsolidated VIEs	4,073	2,966
Nonconsolidated entities \| Trading assets
Firm-sponsored mortgage and other consumer securitization trusts
Interest in securitized assets in nonconsolidated VIEs	1,538	1,327
Nonconsolidated entities \| Investment securities
Firm-sponsored mortgage and other consumer securitization trusts
Interest in securitized assets in nonconsolidated VIEs	2,273	1,398
Nonconsolidated entities \| Other financial assets
Firm-sponsored mortgage and other consumer securitization trusts
Interest in securitized assets in nonconsolidated VIEs	262	241
Nonconsolidated entities \| Residential mortgage \| Prime/Alt-A and option ARMs
Firm-sponsored mortgage and other consumer securitization trusts
Assets held in nonconsolidated securitization VIEs with continuing involvement	41,265	48,734
Interest in securitized assets in nonconsolidated VIEs	1,298	1,160
Nonconsolidated entities \| Residential mortgage \| Subprime
Firm-sponsored mortgage and other consumer securitization trusts
Assets held in nonconsolidated securitization VIEs with continuing involvement	12,154	13,490
Interest in securitized assets in nonconsolidated VIEs	9	7
Nonconsolidated entities \| Residential mortgage \| Trading assets \| Prime/Alt-A and option ARMs
Firm-sponsored mortgage and other consumer securitization trusts
Interest in securitized assets in nonconsolidated VIEs	574	535
Nonconsolidated entities \| Residential mortgage \| Trading assets \| Subprime
Firm-sponsored mortgage and other consumer securitization trusts
Interest in securitized assets in nonconsolidated VIEs	9	7
Nonconsolidated entities \| Residential mortgage \| Investment securities \| Prime/Alt-A and option ARMs
Firm-sponsored mortgage and other consumer securitization trusts
Interest in securitized assets in nonconsolidated VIEs	724	625
Nonconsolidated entities \| Residential mortgage \| Investment securities \| Subprime
Firm-sponsored mortgage and other consumer securitization trusts
Interest in securitized assets in nonconsolidated VIEs	0	0
Nonconsolidated entities \| Residential mortgage \| Other financial assets \| Prime/Alt-A and option ARMs
Firm-sponsored mortgage and other consumer securitization trusts
Interest in securitized assets in nonconsolidated VIEs	0	0
Nonconsolidated entities \| Residential mortgage \| Other financial assets \| Subprime
Firm-sponsored mortgage and other consumer securitization trusts
Interest in securitized assets in nonconsolidated VIEs	0	0
Nonconsolidated entities \| Commercial and other
Firm-sponsored mortgage and other consumer securitization trusts
Assets held in nonconsolidated securitization VIEs with continuing involvement	92,351	80,878
Interest in securitized assets in nonconsolidated VIEs	2,766	1,799
Nonconsolidated entities \| Commercial and other \| Trading assets
Firm-sponsored mortgage and other consumer securitization trusts
Interest in securitized assets in nonconsolidated VIEs	955	785
Nonconsolidated entities \| Commercial and other \| Investment securities
Firm-sponsored mortgage and other consumer securitization trusts
Interest in securitized assets in nonconsolidated VIEs	1,549	773
Nonconsolidated entities \| Commercial and other \| Other financial assets
Firm-sponsored mortgage and other consumer securitization trusts
Interest in securitized assets in nonconsolidated VIEs	$ 262	$ 241

Firm-sponsored mortgage and other consumer securitization trusts.

No definition available.

Name:	jpm_FirmSponsoredMortgageAndOtherConsumerSecuritizationTrustsAbstract
Namespace Prefix:	jpm_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percent of retained securitization interests rated A or better.

+ References

No definition available.

+ Details

Name:	jpm_PercentOfRetainedSecuritizationInterestsFairValueRatedOrBetter
Namespace Prefix:	jpm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Senior securities purchased in connection with IB secondary market making activities. These securities are excluded from entity interest in securitized assets in nonconsolidated VIEs.

+ References

No definition available.

+ Details

Name:	jpm_SeniorSecuritiesPurchasedExcludedFromInterestsContinuedToBeHeldByTransferorFairValue
Namespace Prefix:	jpm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Subordinated securities purchased in connection with IB secondary market making Activities. These securities are excluded from entity interest in securitized assets in nonconsolidated VIEs.

+ References

No definition available.

+ Details

Name:	jpm_SubordinatedSecuritiesPurchasedExcludedFromInterestsContinuedToBeHeldByTransferorFairValue
Namespace Prefix:	jpm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Principal amount of transferred financial assets in which the transferor has continuing involvement with the assets underlying the transaction. Continuing involvement includes, but is not limited to, servicing, recourse, and restrictions on transferor's interests in transferred financial assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719

+ Details

Name:	us-gaap_ContinuingInvolvementWithTransferredFinancialAssetsPrincipalAmountOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of transferred financial assets in which the transferor has continuing involvement with the assets underlying the transaction that have been derecognized. Continuing involvement includes, but is not limited to, servicing, recourse, and restrictions on transferor's interests in transferred financial assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719

+ Details

Name:	us-gaap_DerecognizedAssetsSecuritizedOrAssetbackedFinancingArrangementAssetsAndAnyOtherFinancialAssetsManagedTogetherPrincipalAmountOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The carrying amount (fair value) as of the balance sheet date of the transferor's interests in transferred financial assets (typically securitized receivables, generally not involved in the collection of principal) following transfer of significant portions of such financial instruments to other parties. Such interests could be ancillary cash flows and interest-only strips.

+ 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 (a)(3)
-URI http://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719

+ Details

Name:	us-gaap_InterestsContinuedToBeHeldByTransferorFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value portion of interest continued to be held by a transferor after transferring financial assets to a third party.

+ References

No definition available.

+ Details

Name:	us-gaap_RetainedInterestFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of transferred financial assets in which the transferor has continuing involvement with the assets underlying the transaction that continue to be recognized in the statement of financial position. Includes, but is not limited to, servicing, recourse, and restrictions on transferor's interests in transferred financial assets.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719

+ Details

Name:	us-gaap_SecuritizedAssetsAndAnyOtherFinancialAssetsManagedTogetherPrincipalAmountOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=jpm_CorporateInvestmentBankMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_UnderlyingAssetClassAxis=us-gaap_ResidentialMortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ExternalCreditRatingByGroupingAxis=us-gaap_ExternalCreditRatingInvestmentGradeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_ExternalCreditRatingByGroupingAxis=us-gaap_ExternalCreditRatingNonInvestmentGradeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_PrimeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InternalCreditAssessmentAxis=us-gaap_SubprimeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_UnderlyingAssetClassAxis=us-gaap_CommercialMortgageBackedSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_QualitativeAndQuantitativeInformationTransferorsContinuingInvolvementTransferredFinancialAssetsByTransferOrTransfereeAxis=us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_QualitativeAndQuantitativeInformationTransferorsContinuingInvolvementTransferredFinancialAssetsByTransferOrTransfereeAxis=us-gaap_VariableInterestEntityNotPrimaryBeneficiaryMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=jpm_DebtSecuritiesTradingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=us-gaap_AvailableforsaleSecuritiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_InvestmentTypeAxis=jpm_OtherFinancialAssetsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: