Loans and Accounts Receivable (Details 6) account in Thousands, $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2019 USD ($) account	Sep. 30, 2018 USD ($) account	Sep. 30, 2019 USD ($) account	Sep. 30, 2018 USD ($) account
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Accounts \| account	23	14	61	40
Outstanding Balances \| $	$ 214	$ 122	$ 569	$ 345
Card Member Loans [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Accounts \| account	21	13	55	36
Outstanding Balances \| $	$ 160	$ 98	$ 425	$ 267
Average Interest Rate Reduction (as a percentage)	13.00%	12.00%	13.00%	12.00%
Card Member Receivables [Member]
Financing Receivable, Troubled Debt Restructuring [Line Items]
Number of Accounts \| account	2	1	6	4
Outstanding Balances \| $	$ 54	$ 24	$ 144	$ 78
Average Payment Term Extension (in months)	27 months	27 months	27 months	28 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=118936363&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: