Regulatory Matters and Capital Adequacy (Details Textuals) $ in Billions	12 Months Ended
	Dec. 31, 2019 USD ($)
Regulatory Matters And Capital Adequacy [Abstract]
Restricted net assets of subsidiaries	$ 10.0
Capital conservation buffer	2.50%
Retained earnings available for dividend payment	$ 4.9
American Express National Bank [Member]
Regulatory Matters And Capital Adequacy [Abstract]
Dividends paid from retained earnings to its parent company	$ 3.9