Loans and Card Member Receivables (Details 5) account in Thousands, $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2020 USD ($) account	Sep. 30, 2019 USD ($) account	Sep. 30, 2020 USD ($) account	Sep. 30, 2019 USD ($) account
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Accounts \| account	92	23	262	61
Outstanding Balances \| $	$ 1,045	$ 214	$ 3,315	$ 569
Card Member Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Accounts \| account	76	21	216	55
Outstanding Balances \| $	$ 649	$ 160	$ 1,947	$ 425
Average Interest Rate Reduction (as a percentage)	14.00%	13.00%	14.00%	13.00%
Card Member Receivables [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Accounts \| account	13	2	38	6
Outstanding Balances \| $	$ 231	$ 54	$ 1,049	$ 144
Average Payment Term Extension (in months)	18 months	27 months	19 months	27 months
Other Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Accounts \| account	3		8
Outstanding Balances \| $	$ 165		$ 319
Average Interest Rate Reduction (as a percentage)	3.00%		3.00%
Average Payment Term Extension (in months)	17 months		16 months

The average basis point reduction in interest rate by class of Financial Instrument

No definition available.

Name:	axp_AverageInterestRateReductionByClassOfFinancialInstrument
Namespace Prefix:	axp_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The average period for payment term extension for cardmember receivables modified in a TDR.

+ References

No definition available.

+ Details

Name:	axp_AveragePaymentTermExtension
Namespace Prefix:	axp_
Data Type:	xbrli:durationItemType
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_FinancingReceivableModificationsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953676-111524

+ Details

Name:	us-gaap_FinancingReceivableModificationsNumberOfContracts2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount, after troubled debt restructuring, of modified financing receivable.

+ References

+ Details

Name:	us-gaap_FinancingReceivableModificationsPostModificationRecordedInvestment2
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=axp_CardmemberLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=axp_CardmemberReceivablesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FinancingReceivableRecordedInvestmentByClassOfFinancingReceivableAxis=axp_OtherLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: