Amount of investment that generates income tax credit and other income tax benefit under tax credit program elected to be accounted for using proportional amortization method. Includes, but is not limited to, investment under program not meeting condition for accounting under proportional amortization method.

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478156/740-323-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 323
-Name Accounting Standards Codification
-Section 50
-Paragraph 1A
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478156/740-323-50-1A

+ Details

Name:	us-gaap_AmortizationMethodQualifiedAffordableHousingProjectInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 12
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-12

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 231
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482663/740-10-55-231

+ Details

Name:	us-gaap_EffectiveIncomeTaxRateContinuingOperations
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
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_IncomeTaxContingencyLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Estimated amount of loss resulting from an adverse tax position.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-15

+ Details

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

- Definition

The amount of the unrecognized tax benefit of a position taken for which it is reasonably possible that the total amount thereof will significantly increase or decrease within twelve months of the balance sheet date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-15

+ Details

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

- Definition

The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 217
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482663/740-10-55-217

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 15A
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-15A

+ Details

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

- Details

Name:	us-gaap_IncomeTaxAuthorityNameAxis=us-gaap_InternalRevenueServiceIRSMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	axp_IncomeTaxEstimationEstimationExpenseTypeAxis=axp_PenaltiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Income Taxes (Details Textual) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
Income Taxes (Details Textual) - USD ($) $ in Millions	Dec. 31, 2024	Mar. 31, 2025	Mar. 31, 2024
Income Tax Contingency [Line Items]
Effective tax rates		22.40%	22.50%
Unrecognized tax benefits change as a result of potential resolutions of prior years' tax		$ 132
Unrecognized tax benefits that, if recognized, could impact effective tax rate		104
Tax credit investments		$ 1,699	$ 1,454
Internal Revenue Service (IRS)
Income Tax Contingency [Line Items]
Additional estimated federal income tax payment	$ 185
Internal Revenue Service (IRS) \| Penalties
Income Tax Contingency [Line Items]
Additional estimated federal income tax payment	$ 50