Transactions with Affiliates 3 (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Related Party Transaction [Line Items]
Long Term Debt To Affiliates	$ 7,523	$ 270
Year-End Stated Rate on Debt	2.68%	1.51%
Year-End Stated Rate on Debt	3.20%	0.22%
American Express Company [Member]
Related Party Transaction [Line Items]
Year-End Stated Rate on Debt	3.32%	0.00%
American Express Company [Member] | Maturity November 2023 [Member]
Related Party Transaction [Line Items]
Long Term Debt To Affiliates	$ 7,240	$ 0
Amex Funding Management (Europe) Limited [Member]
Related Party Transaction [Line Items]
Long Term Debt To Affiliates		$ 0
Year-End Stated Rate on Debt	0.28%	0.00%
Amex Funding Management (Europe) Limited [Member] | Maturity September 2021 [Member]
Related Party Transaction [Line Items]
Long Term Debt To Affiliates	$ 283
LB Luxembourg Two S.a.r.l [Member]
Related Party Transaction [Line Items]
Long Term Debt To Affiliates	$ 0	$ 270
Year-End Stated Rate on Debt	0.00%	0.22%