Variable Interest Entities - Re-securitizations (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Transfers of securities to VIEs
Agency	$ 4,503	$ 4,786
Variable Interest Entity [Line Items]
Assets held in VIEs with continuing involvement	182,978		$ 183,040
Firm-sponsored private-label \| Nonconsolidated re-securitization VIEs
Variable Interest Entity [Line Items]
Assets held in VIEs with continuing involvement	24		118
Interest in VIEs	0		10
Agency \| Nonconsolidated re-securitization VIEs
Variable Interest Entity [Line Items]
Interest in VIEs	$ 2,842		$ 3,058

Amount of securities transferred to agency re-securitization VIEs during the period.

No definition available.

Name:	jpm_SecuritiesTransferredToAgencyResecuritizationVies
Namespace Prefix:	jpm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Variable Interest Entity, Transfer of Securities [Abstract]

+ References

No definition available.

+ Details

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

- 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

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- Definition

Net carrying amount of the assets and liabilities in the reporting entity's statement of financial position that relate to the reporting entity's variable interest in the Variable Interest Entity (VIE), when the reporting entity is not the VIE's primary beneficiary.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_MortgageBackedSecuritiesIssuedByPrivateEnterprisesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_FinancialInstrumentAxis=us-gaap_MortgageBackedSecuritiesIssuedByUSGovernmentSponsoredEnterprisesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: