Derivative Instruments - Impact on Statements of Income, Fair Value Hedges (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Gains/(losses) recorded in income
Derivatives	$ (139)	$ (1,417)	$ (1,301)	$ (4,208)
Hedged items	406	1,645	2,136	4,855
Income statement impact	267	228	835	647
Income statement impact of excluded components:
Amortization approach	(137)		(404)
Changes in fair value	267		833
Income statement impact due to:
Hedge ineffectiveness		2		7
Excluded components		226		640
OCI impact
Derivatives - Gains/(losses) recorded in OCI	45		(96)
Interest rate
Gains/(losses) recorded in income
Derivatives	(870)	22	(2,747)	(131)
Hedged items	1,032	182	3,214	759
Income statement impact	162	204	467	628
Income statement impact of excluded components:
Amortization approach	0		0
Changes in fair value	160		459
Income statement impact due to:
Hedge ineffectiveness		(2)		(16)
Excluded components		206		644
OCI impact
Derivatives - Gains/(losses) recorded in OCI	0		0
Foreign exchange
Gains/(losses) recorded in income
Derivatives	277	(982)	797	(3,254)
Hedged items	(165)	1,002	(452)	3,235
Income statement impact	112	20	345	(19)
Income statement impact of excluded components:
Amortization approach	(137)		(404)
Changes in fair value	112		345
Income statement impact due to:
Hedge ineffectiveness		0		0
Excluded components		20		(19)
OCI impact
Derivatives - Gains/(losses) recorded in OCI	45		(96)
Commodity
Gains/(losses) recorded in income
Derivatives	454	(457)	649	(823)
Hedged items	(461)	461	(626)	861
Income statement impact	(7)	4	23	38
Income statement impact of excluded components:
Amortization approach	0		0
Changes in fair value	(5)		29
Income statement impact due to:
Hedge ineffectiveness		4		23
Excluded components		$ 0		$ 15
OCI impact
Derivatives - Gains/(losses) recorded in OCI	$ 0		$ 0

Gain (Loss) from Components Excluded from Assessment of Fair Value Hedge Effectiveness, Amortization Method, Net

No definition available.

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

- Definition

Gain (Loss) from Components Excluded from Assessment of Fair Value Hedge Effectiveness, Changes in Fair Value, Net

+ References

No definition available.

+ Details

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

- Definition

Amount of gain (loss) from the increase (decrease) in fair value of derivative and nonderivative instruments designated as fair value hedging instruments recognized in the income statement.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 25
-Section 50
-Paragraph 1
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=109977999&loc=d3e76258-113986

+ Details

Name:	us-gaap_ChangeInUnrealizedGainLossOnFairValueHedgingInstruments1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of the increase (decrease) in fair value of the hedged item in a fair value hedge recognized in the income statement.

+ References

+ Details

Name:	us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Net gain (loss) relating to components of the gain (loss) on the fair value hedging instrument excluded from the assessment of fair value hedge effectiveness. Recognized in earnings.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 25
-Section 50
-Paragraph 1
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=109977999&loc=d3e76258-113986

+ Details

Name:	us-gaap_GainLossFromComponentsExcludedFromAssessmentOfFairValueHedgeEffectivenessNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

No definition available.

+ Details

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

- Definition

Amount of gain (loss)recognized in the income statement from the hedging ineffectiveness of a fair value hedge.

+ References

+ Details

Name:	us-gaap_GainLossOnFairValueHedgeIneffectivenessNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

No definition available.

+ Details

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

- Definition

Total amount of gain (loss) derived from fair value hedges recognized in earnings in the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959

+ Details

Name:	us-gaap_GainLossOnFairValueHedgesRecognizedInEarnings
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- References

No definition available.

+ Details

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

- References

No definition available.

+ Details

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

- Definition

Amount, before tax and adjustments, of gain (loss) from increase (decrease) in value of excluded component of derivative designated and qualifying as hedge. Adjustments include, but are not limited to, reclassifications for sale and settlement, and amounts recognized under systematic and rational method.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 10A
-Subparagraph (dd)
-URI http://asc.fasb.org/extlink&oid=114867106&loc=SL7669646-108580

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (bb)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624171-113959

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=114867106&loc=d3e637-108580

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4CCC
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109980867&loc=SL109998896-113959

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 20
-Section 45
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=109974929&loc=SL110061190-113977

+ Details

Name:	us-gaap_OtherComprehensiveIncomeLossDerivativeExcludedComponentIncreaseDecreaseBeforeAdjustmentsAndTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_InterestRateContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForeignExchangeContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DerivativeInstrumentRiskAxis=us-gaap_CommodityContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: