Fair Value Option - Aggregate Differences (Details) - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Long-term beneficial interests
Performing loans, ninety days or more past due	$ 0	$ 0
Lending-related commitments, fair value option elected
Long-term beneficial interests
Contractual amount of lending-related commitments	9,700,000,000	6,900,000,000
Contractual lending-related commitments, fair value	(95,000,000)	(82,000,000)
Contractual principal outstanding
Loans
Nonaccrual loans	4,162,000,000	4,279,000,000
Total loans	52,168,000,000	49,680,000,000
Contractual principal outstanding \| Principal-protected debt
Long-term debt
Total long-term debt	39,559,000,000	32,674,000,000
Contractual principal outstanding \| Loans reported as trading assets
Loans
Nonaccrual loans	4,038,000,000	4,240,000,000
All other performing loans	43,722,000,000	42,215,000,000
Contractual principal outstanding \| Loans
Loans
Nonaccrual loans	124,000,000	39,000,000
All other performing loans	4,284,000,000	3,186,000,000
Fair value
Loans
Nonaccrual loans	1,303,000,000	1,350,000,000
Total loans	48,267,000,000	44,904,000,000
Long-term debt
Total long-term debt	67,828,000,000	54,886,000,000
Long-term beneficial interests
Total long-term beneficial interests	0	28,000,000
Fair value \| Principal-protected debt
Long-term debt
Total long-term debt	36,681,000,000	28,718,000,000
Fair value \| Nonprincipal-protected debt
Long-term debt
Total long-term debt	31,147,000,000	26,168,000,000
Long-term beneficial interests
Total long-term beneficial interests	0	28,000,000
Fair value \| Loans reported as trading assets
Loans
Nonaccrual loans	1,231,000,000	1,350,000,000
All other performing loans	42,727,000,000	40,403,000,000
Fair value \| Loans
Loans
Nonaccrual loans	72,000,000	0
All other performing loans	4,237,000,000	3,151,000,000
Fair value over/(under) contractual principal outstanding
Loans
Nonaccrual loans, Fair value over/(under) contractual principal outstanding	(2,859,000,000)	(2,929,000,000)
Total loans	(3,901,000,000)	(4,776,000,000)
Fair value over/(under) contractual principal outstanding \| Principal-protected debt
Long-term debt
Long-term debt, Fair value over/(under) contractual principal outstanding	(2,878,000,000)	(3,956,000,000)
Fair value over/(under) contractual principal outstanding \| Loans reported as trading assets
Loans
Nonaccrual loans, Fair value over/(under) contractual principal outstanding	(2,807,000,000)	(2,890,000,000)
All other performing loans	(995,000,000)	(1,812,000,000)
Fair value over/(under) contractual principal outstanding \| Loans
Loans
Nonaccrual loans, Fair value over/(under) contractual principal outstanding	(52,000,000)	(39,000,000)
All other performing loans	$ (47,000,000)	$ (35,000,000)

Represents the portion of loans held as assets for which the fair value option has been elected, valued at fair value.

No definition available.

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

- Definition

Fair Value Options Other Performing Loans.

+ References

No definition available.

+ Details

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

- Definition

Guarantor Obligations, Net of Other Commitments, Current Carrying Value

+ References

No definition available.

+ Details

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

- Definition

Long Term Beneficial Interests.

+ References

No definition available.

+ Details

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

- Definition

Long term beneficial interests.

+ References

No definition available.

+ Details

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

- Definition

This item represents the difference between the aggregate fair value and the aggregate unpaid principal balance of long-term debt instruments that have contractual principal amounts and for which the fair value option has been elected.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (d)(2)
-URI http://asc.fasb.org/extlink&oid=75031198&loc=d3e14064-108612

+ Details

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

- References

No definition available.

+ Details

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

- Definition

This item represents the aggregate fair value of loans held as assets that are in nonaccrual status for which the fair value option has been elected, if the entity's policy is to recognize interest income separately from other changes in fair value.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (e)(2)
-URI http://asc.fasb.org/extlink&oid=75031198&loc=d3e14064-108612

+ Details

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

- Definition

For loans held as assets for which the fair value option has been elected, this item represents the difference between the aggregate fair value and the aggregate unpaid principal balance of those loans that are in nonaccrual status.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (e)(3)
-URI http://asc.fasb.org/extlink&oid=75031198&loc=d3e14064-108612

+ Details

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

- Definition

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 28
-Subparagraph (e)(3)
-URI http://asc.fasb.org/extlink&oid=75031198&loc=d3e14064-108612

+ Details

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

- Definition

Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 460
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=115931803&loc=d3e12069-110248

+ Details

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

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
-URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031897-161870

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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

- References

No definition available.

+ Details

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

- Details

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

- Details

Name:	us-gaap_FairValueByMeasurementBasisAxis=us-gaap_CarryingReportedAmountFairValueDisclosureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByLiabilityClassAxis=jpm_PrincipalProtectedDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=jpm_TradingLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByAssetClassAxis=us-gaap_LoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByMeasurementBasisAxis=us-gaap_EstimateOfFairValueFairValueDisclosureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByLiabilityClassAxis=jpm_NonPrincipalProtectedDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FairValueByMeasurementBasisAxis=us-gaap_ChangeDuringPeriodFairValueDisclosureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: