Accumulated Other Comprehensive Income/(Loss) - Components of Other Comprehensive Income/(Loss) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Unrealized gains/(losses) on AFS securities:
Net change, Pre-tax	$ 8,066	$ 3,921	$ (1,761)
Net change, Tax effect	(1,649)	(845)	285
Total other comprehensive income/(loss), after–tax	6,417	3,076	(1,476)
Accumulated other comprehensive income/(loss)
Unrealized gains/(losses) on AFS securities:
Total other comprehensive income/(loss), after–tax	6,417	3,076	(1,476)
Accumulated other comprehensive income/(loss) \| Other Income
Unrealized gains/(losses) on AFS securities:
Net pre-tax gain (loss) reclassified related to liquidation of legal entity	6	7
Accumulated other comprehensive income/(loss) \| Other Expense
Unrealized gains/(losses) on AFS securities:
Net pre-tax gain (loss) reclassified related to liquidation of legal entity		1	(168)
Unrealized gains/(losses) on investment securities
Unrealized gains/(losses) on AFS securities:
Net unrealized gains/(losses) arising during the period/Translation, Pre-tax	6,228	4,025	(2,825)
Net unrealized gains/(losses) arising during the period/Translation, Tax effect	(1,495)	(974)	665
Net unrealized gains/(losses) arising during the period/Translation, After-tax	4,733	3,051	(2,160)
Reclassification, Pre-tax	(802)	(258)	395
Reclassification, Tax effect	192	62	(93)
Reclassification, After-tax	(610)	(196)	302
Net change, Pre-tax	5,426	3,767	(2,430)
Net change, Tax effect	(1,303)	(912)	572
Total other comprehensive income/(loss), after–tax	4,123	2,855	(1,858)
Net pre-tax gain (loss) reclassified related to liquidation of legal entity		18
Unrealized gains/(losses) on investment securities \| Other Income
Unrealized gains/(losses) on AFS securities:
Net pre-tax gain (loss) reclassified related to liquidation of legal entity	3	18
Unrealized gains/(losses) on investment securities \| Other Expense
Unrealized gains/(losses) on AFS securities:
Net pre-tax gain (loss) reclassified related to liquidation of legal entity			(17)
Translation adjustments
Unrealized gains/(losses) on AFS securities:
Net unrealized gains/(losses) arising during the period/Translation, Pre-tax	1,407	(49)	(1,078)
Net unrealized gains/(losses) arising during the period/Translation, Tax effect	(103)	33	156
Net unrealized gains/(losses) arising during the period/Translation, After-tax	1,304	(16)	(922)
Reclassification, Pre-tax	(1,411)	46	1,236
Reclassification, Tax effect	341	(10)	(294)
Reclassification, After-tax	(1,070)	36	942
Net change, Pre-tax	(4)	(3)	158
Net change, Tax effect	238	23	(138)
Total other comprehensive income/(loss), after–tax	234	20	20
Net pre-tax gain (loss) reclassified related to liquidation of legal entity		(10)
Translation adjustments \| Other Income
Unrealized gains/(losses) on AFS securities:
Net pre-tax gain (loss) reclassified related to liquidation of legal entity	3
Translation adjustments \| Other Expense
Unrealized gains/(losses) on AFS securities:
Net pre-tax gain (loss) reclassified related to liquidation of legal entity			(151)
Fair value hedges, net of change
Unrealized gains/(losses) on AFS securities:
Net change, Pre-tax	25	39	(140)
Net change, Tax effect	(6)	(9)	33
Total other comprehensive income/(loss), after–tax	19	30	(107)
Cash flow hedges
Unrealized gains/(losses) on AFS securities:
Net unrealized gains/(losses) arising during the period/Translation, Pre-tax	3,623	122	(245)
Net unrealized gains/(losses) arising during the period/Translation, Tax effect	(870)	(28)	58
Net unrealized gains/(losses) arising during the period/Translation, After-tax	2,753	94	(187)
Reclassification, Pre-tax	(570)	103	(18)
Reclassification, Tax effect	137	(25)	4
Reclassification, After-tax	(433)	78	(14)
Net change, Pre-tax	3,053	225	(263)
Net change, Tax effect	(733)	(53)	62
Total other comprehensive income/(loss), after–tax	2,320	172	(201)
Defined benefit pension and OPEB plans
Unrealized gains/(losses) on AFS securities:
Net change, Pre-tax	214	1,157	(450)
Net change, Tax effect	(2)	(193)	77
Total other comprehensive income/(loss), after–tax	212	964	(373)
DVA on fair value option elected liabilities, net change
Unrealized gains/(losses) on AFS securities:
Net change, Pre-tax	(648)	(1,264)	1,364
Net change, Tax effect	157	299	(321)
Total other comprehensive income/(loss), after–tax	$ (491)	$ (965)	$ 1,043

Amount before tax and reclassification adjustments of other comprehensive income (loss) attributable to parent.

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

- Definition

Amount after tax, before reclassification adjustments, of other comprehensive income (loss), attributable to parent.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 55
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=121640130&loc=d3e1436-108581

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14A
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669686-108580

+ Details

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

- References

No definition available.

+ Details

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

- Definition

Amount of tax expense (benefit) allocated to other comprehensive income (loss) before reclassification adjustment from accumulated other comprehensive income (loss).

+ References

+ Details

Name:	us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount before tax of other comprehensive income (loss) attributable to parent entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 19
-URI http://asc.fasb.org/extlink&oid=108774443&loc=SL4569616-111683

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=108774443&loc=SL4569643-111683

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684

+ Details

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

- Definition

Amount before tax of reclassification adjustment from accumulated other comprehensive income for translation gain (loss) realized upon the sale or liquidation of an investment in a foreign entity and foreign currency hedges that are designated and qualified as hedging instruments for hedges of the foreign currency exposure of a net investment in a foreign operation.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 30
-Section 40
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=116633155&loc=d3e31531-110899

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=121641772&loc=d3e637-108580

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 17A
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL34724391-108580

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 16
-URI http://asc.fasb.org/extlink&oid=121641772&loc=d3e709-108580

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=121641772&loc=d3e689-108580

+ Details

Name:	us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationReclassificationAdjustmentFromAOCIRealizedUponSaleOrLiquidationBeforeTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount after tax of other comprehensive income (loss) attributable to parent entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1B
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669625-108580

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=108774443&loc=SL4569643-111683

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 1A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669619-108580

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 19
-URI http://asc.fasb.org/extlink&oid=108774443&loc=SL4569616-111683

+ Details

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

- Definition

Amount of tax expense (benefit) allocated to other comprehensive income (loss) attributable to parent entity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 20
-URI http://asc.fasb.org/extlink&oid=108774443&loc=SL4569643-111683

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 45
-Paragraph 19
-URI http://asc.fasb.org/extlink&oid=108774443&loc=SL4569616-111683

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (c)(3)
-URI http://asc.fasb.org/extlink&oid=109239629&loc=SL4573702-111684

+ Details

Name:	us-gaap_OtherComprehensiveIncomeLossTaxPortionAttributableToParent1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount before tax of reclassification adjustments of other comprehensive income (loss) attributable to parent.

+ References

+ Details

Name:	us-gaap_ReclassificationFromAociCurrentPeriodBeforeTaxAttributableToParent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount after tax of reclassification adjustments of other comprehensive income (loss) attributable to parent.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14A
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL7669686-108580

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 55
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=121640130&loc=d3e1436-108581

+ Details

Name:	us-gaap_ReclassificationFromAociCurrentPeriodNetOfTaxAttributableToParent
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of tax expense (benefit) of reclassification adjustment from accumulated other comprehensive income (loss).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=121641772&loc=d3e640-108580

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 17A
-URI http://asc.fasb.org/extlink&oid=121641772&loc=SL34724391-108580

+ Details

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

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedOtherComprehensiveIncomeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_OtherIncomeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_IncomeStatementLocationAxis=us-gaap_OtherExpenseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedNetUnrealizedInvestmentGainLossMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedTranslationAdjustmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_AociDerivativeQualifyingAsHedgeExcludedComponentParentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=jpm_AccumulatedGainLossFairValueOptionFinancialLiabilitiesAttributabletoParentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: