Securities Financing Activities - Types of Financial Assets Pledged and Remaining Maturity (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	$ 667,703	$ 541,587
Securities loaned and other	40,722	33,700
Overnight and continuous
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	354,509	247,579
Securities loaned and other	31,657	28,402
Up to 30 days
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	175,020	174,971
Securities loaned and other	943	997
30 – 90 days
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	77,551	71,637
Securities loaned and other	834	2,132
Greater than 90 days
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	60,623	47,400
Securities loaned and other	7,288	2,169
Mortgage-backed securities, U.S. government agencies
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	56,156	28,811
Securities loaned and other	0	0
Mortgage-backed securities, Residential - nonagency
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	1,679	2,165
Securities loaned and other	0	0
Mortgage-backed securities, Commercial - nonagency
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	1,572	1,390
Securities loaned and other	0	0
U.S. Treasury and government agencies
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	387,049	323,078
Securities loaned and other	13	69
Obligations of U.S. states and municipalities
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	1,079	1,150
Securities loaned and other	0	0
Non-U.S. government debt
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	189,092	154,900
Securities loaned and other	3,163	4,313
Corporate debt securities
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	14,348	13,898
Securities loaned and other	953	428
Asset-backed securities
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	2,734	3,867
Securities loaned and other	0	0
Equity securities
Securities Financing Transaction [Line Items]
Securities sold under repurchase agreements	13,994	12,328
Securities loaned and other	$ 36,593	$ 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: