Investment Securities - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
Jun. 30, 2021	Dec. 31, 2020	Jun. 30, 2020
Schedule of Held-to-maturity Securities [Line Items]
Amount of investment securities transferred from AFS to HTM for capital management purposes	$ 104,500
Approximate percentage rated at least AA+	97.00%	98.00%
Investment securities, allowance for credit losses	$ 87	$ 78	$ 23
Unrealized gains/(losses) on investment securities
Schedule of Held-to-maturity Securities [Line Items]
Pretax unrealized gains included in AOCI on the securities at the date of transfer	$ 425

Debt Securities, Available-for-Sale and Held-to-Maturity, Allowance for Credit Loss

No definition available.

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

- Definition

Debt Securities, Available-for-sale, Transfer to Held-to-maturity, Amount

+ References

No definition available.

+ Details

Name:	jpm_DebtSecuritiesAvailableforsaleTransfertoHeldtomaturityAmount
Namespace Prefix:	jpm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Debt Securities, Held-To-Maturity, External Credit Rating, Percent Rated AA Plus Or Higher

+ References

No definition available.

+ Details

Name:	jpm_DebtSecuritiesHeldToMaturityExternalCreditRatingPercentRatedAAPlusOrHigher
Namespace Prefix:	jpm_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount, before tax, of adjustment from accumulated other comprehensive income (loss) for amortization of gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale) from transfer to investment in debt security measured at amortized cost (held-to-maturity).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 35
-Paragraph 10B
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121568769&loc=SL120268667-111560

+ Details

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

- Definition

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.

+ References

No definition available.

+ Details

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

- Details

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