Debt (Details 1) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Long-term Debt	$ 58,423	$ 55,804
Unamortized Underwriting Fees	$ (117)	$ (111)
Long-term Debt [Member]
Debt Instrument [Line Items]
Year-End Stated Rate on Debt	2.77%	2.44%
Parent Company [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 18,191	$ 12,695
Fixed Rate Senior Notes Amount [Member] | Parent Company [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 14,043	$ 10,377
Year-End Effective Interest Rates with Swaps	3.64%	3.17%
Fixed Rate Senior Notes Amount [Member] | Parent Company [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Year-End Stated Rate on Debt	3.48%	3.85%
Fixed Rate Senior Notes Amount [Member] | American Express National Bank [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 0
Year-End Effective Interest Rates with Swaps	0.00%
Fixed Rate Senior Notes Amount [Member] | American Express National Bank [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Year-End Stated Rate on Debt	0.00%
Fixed Rate Senior Notes Amount [Member] | American Express Credit Corporation [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 16,677	$ 19,652
Year-End Effective Interest Rates with Swaps	3.06%	2.27%
Fixed Rate Senior Notes Amount [Member] | American Express Credit Corporation [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Year-End Stated Rate on Debt	2.28%	2.24%
Fixed Rate Senior Notes Amount [Member] | American Express Lending Trust [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 12,474	$ 8,099
Year-End Effective Interest Rates with Swaps	0.00%	0.00%
Fixed Rate Senior Notes Amount [Member] | American Express Lending Trust [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Year-End Stated Rate on Debt	2.28%	1.90%
Floating Rate Senior Notes Amount [Member] | Parent Company [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 3,600	$ 1,750
Year-End Effective Interest Rates with Swaps	0.00%	0.00%
Floating Rate Senior Notes Amount [Member] | Parent Company [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Year-End Stated Rate on Debt	3.17%	1.93%
Floating Rate Senior Notes Amount [Member] | American Express National Bank [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 0	$ 125
Year-End Effective Interest Rates with Swaps	0.00%	0.00%
Floating Rate Senior Notes Amount [Member] | American Express National Bank [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Year-End Stated Rate on Debt	0.00%	1.89%
Floating Rate Senior Notes Amount [Member] | American Express Credit Corporation [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 3,800	$ 4,550
Year-End Effective Interest Rates with Swaps	0.00%	0.00%
Floating Rate Senior Notes Amount [Member] | American Express Credit Corporation [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Year-End Stated Rate on Debt	3.31%	2.09%
Floating Rate Senior Notes Amount [Member] | American Express Charge Trust II [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 1,535	$ 4,200
Year-End Effective Interest Rates with Swaps	0.00%	0.00%
Floating Rate Senior Notes Amount [Member] | American Express Charge Trust II [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Year-End Stated Rate on Debt	2.89%	1.79%
Floating Rate Senior Notes Amount [Member] | American Express Lending Trust [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 5,125	$ 5,800
Year-End Effective Interest Rates with Swaps	0.00%	0.00%
Floating Rate Senior Notes Amount [Member] | American Express Lending Trust [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Year-End Stated Rate on Debt	2.80%	2.03%
Floating Rate Subordinated Notes Amount [Member] | American Express Charge Trust II [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 0	$ 87
Year-End Effective Interest Rates with Swaps	0.00%	0.00%
Floating Rate Subordinated Notes Amount [Member] | American Express Charge Trust II [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Year-End Stated Rate on Debt	0.00%	2.11%
Floating Rate Subordinated Notes Amount [Member] | American Express Lending Trust [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 167	$ 192
Year-End Effective Interest Rates with Swaps	0.00%	0.00%
Floating Rate Subordinated Notes Amount [Member] | American Express Lending Trust [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Year-End Stated Rate on Debt	2.96%	2.05%
Convertible Subordinated Debt [Member] | Parent Company [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 598	$ 598
Year-End Effective Interest Rates with Swaps	3.66%	2.66%
Convertible Subordinated Debt [Member] | Parent Company [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Year-End Stated Rate on Debt	3.63%	3.63%
Fixed Rate Subordinated Notes Amount [Member] | American Express Lending Trust [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 240	$ 206
Year-End Effective Interest Rates with Swaps	0.00%	0.00%
Fixed Rate Subordinated Notes Amount [Member] | American Express Lending Trust [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Year-End Stated Rate on Debt	2.37%	2.21%
Fixed Rate Instruments [Member] | Other Subsidiaries [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 19	$ 23
Year-End Effective Interest Rates with Swaps	0.00%	0.00%
Fixed Rate Instruments [Member] | Other Subsidiaries [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Year-End Stated Rate on Debt	5.54%	5.59%
Fixed Rate Instruments [Member] | Other Subsidiaries [Member] | Capitalized lease transactions
Debt Instrument [Line Items]
Long-term Debt	$ 19	$ 23
Floating Rate Borrowings [Member] | Other Subsidiaries [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 262	$ 256
Year-End Effective Interest Rates with Swaps	0.00%	0.00%
Floating Rate Borrowings [Member] | Other Subsidiaries [Member] | Long-term Debt [Member]
Debt Instrument [Line Items]
Year-End Stated Rate on Debt	0.42%	0.42%