Transactions with Affiliates 2 (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
Short-term debt to affiliates	$ 6,225	$ 5,899	$ 5,997
AE Exposure Management Limited [Member]
Related Party Transaction [Line Items]
Short-term debt to affiliates	5,731	5,122
American Express Europe LLC [Member]
Related Party Transaction [Line Items]
Short-term debt to affiliates	219	517
American Express Holdings Netherlands CV [Member]
Related Party Transaction [Line Items]
Short-term debt to affiliates	192	192
Accertify Inc. [Member]
Related Party Transaction [Line Items]
Short-term debt to affiliates	82	68
American Express Swiss Holdings Gmbh [Member]
Related Party Transaction [Line Items]
Short-term debt to affiliates	$ 1	$ 0