Asset Securitizations (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Assets from Trusts [Line Items]
Restricted cash and cash equivalents	$ 1,330	$ 427
American Express Lending Trust
Assets from Trusts [Line Items]
Direct and Indirect ownership of variable interests	12,500	14,600
Restricted cash and cash equivalents	1,238	88
American Express Charge Trust
Assets from Trusts [Line Items]
Direct and Indirect ownership of variable interests	6,700	3,900
Restricted cash and cash equivalents	$ 0	$ 0