Asset Securitizations (Details Textuals) - USD ($) $ in Billions	Sep. 30, 2020	Dec. 31, 2019
American Express Lending Trust [Member]
Securitized Trusts [Line Items]
Direct and Indirect ownership of variable interests	$ 10.9	$ 12.9
American Express Charge Trust [Member]
Securitized Trusts [Line Items]
Direct and Indirect ownership of variable interests	$ 4.3	$ 8.3

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