Securities Financing Activities - Types of Financial Assets Pledged and Remaining Maturity (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	$ 635,858	$ 541,587
Securities loaned and other	33,408	33,700
Overnight and continuous
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	342,097	247,579
Securities loaned and other	29,654	28,402
Up to 30 days
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	163,805	174,971
Securities loaned and other	1,228	997
30 – 90 days
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	64,822	71,637
Securities loaned and other	514	2,132
Greater than 90 days
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	65,134	47,400
Securities loaned and other	2,012	2,169
Mortgage-backed securities, U.S. government agencies
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	25,607	28,811
Securities loaned and other	0	0
Mortgage-backed securities, Residential - nonagency
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	1,675	2,165
Securities loaned and other	0	0
Mortgage-backed securities, Commercial - nonagency
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	1,654	1,390
Securities loaned and other	0	0
U.S. Treasury and government agencies
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	382,199	323,078
Securities loaned and other	10	69
Obligations of U.S. states and municipalities
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	1,509	1,150
Securities loaned and other	0	0
Non-U.S. government debt
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	190,950	154,900
Securities loaned and other	1,912	4,313
Corporate debt securities
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	13,151	13,898
Securities loaned and other	1,301	428
Asset-backed securities
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	2,476	3,867
Securities loaned and other	0	0
Equity securities
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	16,637	12,328
Securities loaned and other	$ 30,185	$ 28,890

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.

No definition available.

+ Details

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

- Definition

Amount, before effects of master netting arrangements, of securities loaned to entities in exchange for collateral. Includes liabilities not subject to a master netting arrangement and elected not to be offset.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

+ Details

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

- Definition

Amount, before effects of master netting arrangements, of funds outstanding borrowed in the form of a security repurchase agreement between the entity and another party for the sale and repurchase of identical or substantially the same securities at a date certain for a specified price. Includes liabilities not subject to a master netting arrangement and elected not to be offset.

+ References

+ Details

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

- Details

Name:	us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis=jpm_MaturityOvernightandContinuousMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis=us-gaap_MaturityUpTo30DaysMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis=us-gaap_Maturity30To90DaysMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_AssetsSoldUnderAgreementsToRepurchaseMaturityPeriodsAxis=us-gaap_MaturityOver90DaysMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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

- Details

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