Variable Interest Entity (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Variable Interest Entity [Line Items]
Total assets	$ 31,981	$ 32,840
Total liabilities	29,689	30,451
Variable Interest Entity, Primary Beneficiary [Member] | American Express Canada Credit Corporation Member [Member]
Variable Interest Entity [Line Items]
Total assets	1,900	2,100
Total liabilities	1,900	2,000
Liabilities eliminated in consolidation	$ 910	$ 969