Asset Securitizations (Details Textuals) $ in Billions	Jun. 30, 2018 USD ($)
American Express Charge Trust [Member]
Securitized Trusts [Line Items]
Direct and Indirect ownership of variable interests	$ 5.2
American Express Lending Trust [Member]
Securitized Trusts [Line Items]
Direct and Indirect ownership of variable interests	$ 7.7

Direct and Indirect ownership of variable interests with the exception of the debt securities issued to third party investors.

No definition available.

Name:	axp_DirectAndIndirectOwnershipOfVariableInterests
Namespace Prefix:	axp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant