Income Taxes	9 Months Ended
Sep. 30, 2016
Income Taxes [Abstract]
Income Taxes	8. Income Taxes The results of operations of Credco are included in the consolidated U.S. federal income tax return of American Express. Under an agreement with American Express, provision for income taxes is recognized on a separate company basis. If benefits for net operating losses, future tax deductions and foreign tax credits cannot be recognized on a separate company basis, such benefits are then recognized based upon a share, derived by formula, of those deductions and credits that are recognizable on an American Express consolidated reporting basis. American Express is under continuous examination by the Internal Revenue Service (IRS) and tax authorities in other countries and states in which American Express has significant business operations. The tax years under examination and open for examination vary by jurisdiction. The IRS has completed its field examination of American Express’ federal tax returns for years through 2007; however, refund claims for certain years continue to be reviewed by the IRS. In addition, American Express is currently under examination by the IRS for the years 2008 through 2014. Credco believes it is reasonably possible that its unrecognized tax benefits could decrease within the next 12 months by as much as $294 million principally as a result of potential resolutions of prior years’ tax items with various taxing authorities. The prior years’ tax items include unrecognized tax benefits relating to the attribution of taxable income to a particular jurisdiction or jurisdictions. Of the $294 million of unrecognized tax benefits, approximately $289 million relates to amounts that if recognized would be recorded in shareholder’s equity and would not impact Credco’s results of operations or its effective tax rate. The effective tax rate was 14.3 percent and 12.5 percent for the three and nine months ended September 30, 2016, respectively, and 13.3 percent and 15.2 percent for the three and nine months ended September 30, 2015, respectively. The changes in tax rates primarily reflected the geographic mix of expenses in the United States attracting a 35 percent statutory benefit and foreign earnings taxed at lower rates, which are indefinitely reinvested. In addition, the effective tax rate in each of the periods reflects the impact of certain prior years’ tax items. The results for the nine months ended September 30, 2015 reflect out-of-period corrections that increased tax expense by $11 million. The corrections relate to tax calculations of foreign exchange gains/losses in one jurisdiction reflected in the 2014 results. None of the current or prior period financial statements were materially misstated from these corrections. The tax rate in each of the periods reflects the favorable impact of the tax benefit related to Credco’s ongoing funding activities outside the United States. Credco’s provision for income taxes for interim financial periods is not based on an estimated annual effective rate due to volatility in certain components of revenues and expenses that prevents Credco from projecting a reliable estimate of full year pretax income. A discrete calculation of the provision for income taxes is calculated for each interim period.

8. Income Taxes

The results of operations of Credco are included in the consolidated U.S. federal income tax return of American Express. Under an agreement with American Express, provision for income taxes is recognized on a separate company basis. If benefits for net operating losses, future tax deductions and foreign tax credits cannot be recognized on a separate company basis, such benefits are then recognized based upon a share, derived by formula, of those deductions and credits that are recognizable on an American Express consolidated reporting basis.

American Express is under continuous examination by the Internal Revenue Service (IRS) and tax authorities in other countries and states in which American Express has significant business operations. The tax years under examination and open for examination vary by jurisdiction. The IRS has completed its field examination of American Express’ federal tax returns for years through 2007; however, refund claims for certain years continue to be reviewed by the IRS. In addition, American Express is currently under examination by the IRS for the years 2008 through 2014.

Credco believes it is reasonably possible that its unrecognized tax benefits could decrease within the next 12 months by as much as $294 million principally as a result of potential resolutions of prior years’ tax items with various taxing authorities. The prior years’ tax items include unrecognized tax benefits relating to the attribution of taxable income to a particular jurisdiction or jurisdictions. Of the $294 million of unrecognized tax benefits, approximately $289 million relates to amounts that if recognized would be recorded in shareholder’s equity and would not impact Credco’s results of operations or its effective tax rate.

The effective tax rate was 14.3 percent and 12.5 percent for the three and nine months ended September 30, 2016, respectively, and 13.3 percent and 15.2 percent for the three and nine months ended September 30, 2015, respectively. The changes in tax rates primarily reflected the geographic mix of expenses in the United States attracting a 35 percent statutory benefit and foreign earnings taxed at lower rates, which are indefinitely reinvested. In addition, the effective tax rate in each of the periods reflects the impact of certain prior years’ tax items.

The results for the nine months ended September 30, 2015 reflect out-of-period corrections that increased tax expense by $11 million. The corrections relate to tax calculations of foreign exchange gains/losses in one jurisdiction reflected in the 2014 results. None of the current or prior period financial statements were materially misstated from these corrections.

The tax rate in each of the periods reflects the favorable impact of the tax benefit related to Credco’s ongoing funding activities outside the United States. Credco’s provision for income taxes for interim financial periods is not based on an estimated annual effective rate due to volatility in certain components of revenues and expenses that prevents Credco from projecting a reliable estimate of full year pretax income. A discrete calculation of the provision for income taxes is calculated for each interim period.