Transactions with Affiliates 3 (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018
Related Party Transaction [Line Items]
Outstanding Balance	$ 13,469	$ 20,447
Affiliated Entity [Member]
Related Party Transaction [Line Items]
Outstanding Balance	$ 9,292	$ 7,523
Year-End Stated Rate on Debt	2.76%	3.20%
American Express Company [Member] | Maturity November 2023 [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Outstanding Balance	$ 8,959	$ 7,240
Year-End Stated Rate on Debt	2.85%	3.32%
Amex Funding Management (Europe) Limited [Member] | Maturity September 2021 [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Outstanding Balance	$ 333	$ 283
Year-End Stated Rate on Debt	0.28%	0.28%