Income Taxes	3 Months Ended
Mar. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	K. Income Taxes – The effective tax rate for the first quarter of 2015 and 2014 was 47.0% (provision on income) and 28.1% (benefit on a loss), respectively. The rate for the 2015 first quarter differs from the U.S. federal statutory rate of 35% primarily due to a loss on the sale of a rolling mill in Russia (see Note E) for which no tax benefit was recognized, a $35 unfavorable impact related to the interim period treatment of losses in certain foreign jurisdictions for which no tax benefit was recognized (impact is expected to reverse by the end of 2015), and a $33 net discrete income tax charge as described below, somewhat offset by foreign income taxed in lower rate jurisdictions. In the first quarter of 2015, AWAC, a joint venture owned 60% by Alcoa and 40% by Alumina Limited (Alcoa consolidates AWAC for financial reporting purposes), recognized an $83 discrete income tax charge for a valuation allowance on certain deferred tax assets, which were related mostly to employee benefits and tax loss carryforwards. Alcoa also had a $50 deferred tax liability related to its 60%-share of these deferred tax assets that was written off as a result of the valuation allowance recognized by AWAC. The rate for the 2014 first quarter differs from the U.S. federal statutory rate of 35% primarily due to a $56 unfavorable impact related to the interim period treatment of operational losses in certain foreign jurisdictions for which no tax benefit was recognized (impact reversed by the end of 2014), partially offset by the U.S. tax impact of deemed distributions from otherwise lower tax rate foreign jurisdictions.

Income Taxes

3 Months Ended

Mar. 31, 2015

K. Income Taxes – The effective tax rate for the first quarter of 2015 and 2014 was 47.0% (provision on income) and 28.1% (benefit on a loss), respectively.

The rate for the 2015 first quarter differs from the U.S. federal statutory rate of 35% primarily due to a loss on the sale of a rolling mill in Russia (see Note E) for which no tax benefit was recognized, a $35 unfavorable impact related to the interim period treatment of losses in certain foreign jurisdictions for which no tax benefit was recognized (impact is expected to reverse by the end of 2015), and a $33 net discrete income tax charge as described below, somewhat offset by foreign income taxed in lower rate jurisdictions.

In the first quarter of 2015, AWAC, a joint venture owned 60% by Alcoa and 40% by Alumina Limited (Alcoa consolidates AWAC for financial reporting purposes), recognized an $83 discrete income tax charge for a valuation allowance on certain deferred tax assets, which were related mostly to employee benefits and tax loss carryforwards. Alcoa also had a $50 deferred tax liability related to its 60%-share of these deferred tax assets that was written off as a result of the valuation allowance recognized by AWAC.

The rate for the 2014 first quarter differs from the U.S. federal statutory rate of 35% primarily due to a $56 unfavorable impact related to the interim period treatment of operational losses in certain foreign jurisdictions for which no tax benefit was recognized (impact reversed by the end of 2014), partially offset by the U.S. tax impact of deemed distributions from otherwise lower tax rate foreign jurisdictions.