Variable Interest Entities - Firm Sponsored Variable Interest Entities (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Firm-sponsored mortgage and other consumer securitization trusts
Total assets held by securitization VIEs	$ 183,040	$ 182,763
Retained securitization interests, risk-rated 'A' or better, at fair value	60.00%	61.00%
Corporate & Investment Bank
Firm-sponsored mortgage and other consumer securitization trusts
Senior securities purchased in connection with CIB's secondary market-making activities	$ 87	$ 88
Subordinated securities purchased in connection with CIB's secondary market-making activities	28	48
Residential mortgage \| Investment-grade
Firm-sponsored mortgage and other consumer securitization trusts
Fair value of retained interests	1,300	1,300
Residential mortgage \| Noninvestment-grade
Firm-sponsored mortgage and other consumer securitization trusts
Fair value of retained interests	16	48
Residential mortgage \| Prime/Alt-A and option ARMs
Firm-sponsored mortgage and other consumer securitization trusts
Total assets held by securitization VIEs	63,350	68,874
Residential mortgage \| Subprime
Firm-sponsored mortgage and other consumer securitization trusts
Total assets held by securitization VIEs	16,729	18,984
Commercial and other
Firm-sponsored mortgage and other consumer securitization trusts
Total assets held by securitization VIEs	102,961	94,905
Commercial and other \| Investment-grade
Firm-sponsored mortgage and other consumer securitization trusts
Fair value of retained interests	1,200	1,600
Commercial and other \| Noninvestment-grade
Firm-sponsored mortgage and other consumer securitization trusts
Fair value of retained interests	623	412
VIEs consolidated by the Firm
Firm-sponsored mortgage and other consumer securitization trusts
Assets held in consolidated securitization VIEs	3,269	3,685
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	3,237	3,615
VIEs consolidated by the Firm \| Residential mortgage \| Subprime
Firm-sponsored mortgage and other consumer securitization trusts
Assets held in consolidated securitization VIEs	32	7
VIEs consolidated by the Firm \| Commercial and other
Firm-sponsored mortgage and other consumer securitization trusts
Assets held in consolidated securitization VIEs	0	63
Nonconsolidated entities
Firm-sponsored mortgage and other consumer securitization trusts
Assets held in nonconsolidated securitization VIEs with continuing involvement	145,500	133,303
Interest in securitized assets in nonconsolidated VIEs	3,117	3,481
Nonconsolidated entities \| Trading assets
Firm-sponsored mortgage and other consumer securitization trusts
Interest in securitized assets in nonconsolidated VIEs	1,459	1,248
Nonconsolidated entities \| Investment securities
Firm-sponsored mortgage and other consumer securitization trusts
Interest in securitized assets in nonconsolidated VIEs	1,448	2,076
Nonconsolidated entities \| Other financial assets
Firm-sponsored mortgage and other consumer securitization trusts
Interest in securitized assets in nonconsolidated VIEs	210	157
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	50,679	52,280
Interest in securitized assets in nonconsolidated VIEs	1,270	1,353
Nonconsolidated entities \| Residential mortgage \| Subprime
Firm-sponsored mortgage and other consumer securitization trusts
Assets held in nonconsolidated securitization VIEs with continuing involvement	15,434	17,612
Interest in securitized assets in nonconsolidated VIEs	53	93
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	623	410
Nonconsolidated entities \| Residential mortgage \| Trading assets \| Subprime
Firm-sponsored mortgage and other consumer securitization trusts
Interest in securitized assets in nonconsolidated VIEs	53	93
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	647	943
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	79,387	63,411
Interest in securitized assets in nonconsolidated VIEs	1,794	2,035
Nonconsolidated entities \| Commercial and other \| Trading assets
Firm-sponsored mortgage and other consumer securitization trusts
Interest in securitized assets in nonconsolidated VIEs	783	745
Nonconsolidated entities \| Commercial and other \| Investment securities
Firm-sponsored mortgage and other consumer securitization trusts
Interest in securitized assets in nonconsolidated VIEs	801	1,133
Nonconsolidated entities \| Commercial and other \| Other financial assets
Firm-sponsored mortgage and other consumer securitization trusts
Interest in securitized assets in nonconsolidated VIEs	$ 210	$ 157

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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=109247956&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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=109247956&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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=109247956&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

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 10
-Section 15
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=108778291&loc=d3e94415-111705

+ 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://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)(3)
-URI http://asc.fasb.org/extlink&oid=109247956&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: