Regulatory Matters and Capital Adequacy (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Regulatory Matters And Capital Adequacy [Abstract]
Well-capitalized ratios	10.00%
Minimum capital ratios	8.00%
Leverage capital required, Well-capitalized ratios	5.00%
Leverage capital required, Minimum capital ratios	4.00%
Risk-based capital required, Well-capitalized ratios	8.00%
Risk-based capital required, Minimum capital ratios	6.00%
Common Equity Tier 1 required, Minimum capital ratio	4.50%
Common Equity Tier 1 required, Well-capitalized ratios	6.50%
Parent Company [Member]
Regulatory capital ratios
Tier 1 capital	$ 18,265	$ 18,176
Total capital	$ 20,551	$ 20,801
Tier 1 capital ratio	13.51%	13.60%
Total capital ratio	15.20%	15.60%
Tier 1 leverage ratio	11.68%	11.80%
CET1 capital	$ 16,747	$ 17,525
CET1 capital ratio	12.40%	13.10%
American Express Centurion Bank [Member]
Regulatory capital ratios
Tier 1 capital	$ 6,013	$ 6,174
Total capital	$ 6,460	$ 6,584
Tier 1 capital ratio	16.90%	18.80%
Total capital ratio	18.20%	20.10%
Tier 1 leverage ratio	17.70%	18.70%
CET1 capital	$ 6,013	$ 6,174
CET1 capital ratio	16.90%	18.80%
American Express Bank, FSB [Member]
Regulatory capital ratios
Tier 1 capital	$ 6,927	$ 6,722
Total capital	$ 7,601	$ 7,604
Tier 1 capital ratio	13.70%	14.20%
Total capital ratio	15.10%	16.00%
Tier 1 leverage ratio	13.20%	15.10%
CET1 capital	$ 6,927	$ 6,722
CET1 capital ratio	13.70%	14.20%