Income Taxes	6 Months Ended
Jun. 30, 2013
Income Tax Disclosure [Abstract]
Income Taxes	J. Income Taxes – The effective tax rate for the second quarter of 2013 and 2012 was 16.5% (provision on a loss) and 216.7% (provision on a loss), respectively. The rate for the 2013 second quarter differs from the U.S. federal statutory rate of 35% primarily due to a $103 nondeductible charge for a legal matter (see the Government Investigations section under Litigation in Note F), restructuring charges related to operations in Canada (benefit at a lower tax rate) and Italy (no tax benefit) (see Note C), and a $10 discrete income tax charge related to prior year taxes in Spain and Australia. The rate for the 2012 second quarter differs from the U.S. federal statutory rate of 35% primarily due to an $8 discrete income tax charge related to prior year U.S. taxes on certain depletable assets and a net $2 discrete income tax charge for other miscellaneous items. The effective tax rate for the 2013 and 2012 six-month periods was 79.4% (provision on income) and 39.4% (provision on income), respectively. The rate for the 2013 six-month period differs from the U.S. federal statutory rate of 35% primarily due to the previously mentioned $103 nondeductible charge, restructuring charges in Canada and Italy, and $10 discrete income tax charge, somewhat offset by a $19 discrete income tax benefit related to new U.S. tax legislation. On January 2, 2013, the American Taxpayer Relief Act of 2012 was signed into law and reinstated various expired or expiring temporary business tax provisions through 2013. Two specific temporary business tax provisions that expired in 2011 and impacted Alcoa are the look-through rule for payments between related controlled foreign corporations and the research and experimentation credit. The expiration of these two provisions resulted in Alcoa recognizing a higher income tax provision of $19 in 2012. As tax law changes are accounted for in the period of enactment, Alcoa recognized the previously mentioned discrete income tax benefit in the 2013 first quarter related to the 2012 tax year to reflect the extension of these provisions. The rate for the 2012 six-month period differs from the U.S. federal statutory rate of 35% primarily due to the previously mentioned discrete income tax charges, partially offset by foreign income taxed in lower rate jurisdictions.

Income Taxes

6 Months Ended

Jun. 30, 2013

J. Income Taxes – The effective tax rate for the second quarter of 2013 and 2012 was 16.5% (provision on a loss) and 216.7% (provision on a loss), respectively.

The rate for the 2013 second quarter differs from the U.S. federal statutory rate of 35% primarily due to a $103 nondeductible charge for a legal matter (see the Government Investigations section under Litigation in Note F), restructuring charges related to operations in Canada (benefit at a lower tax rate) and Italy (no tax benefit) (see Note C), and a $10 discrete income tax charge related to prior year taxes in Spain and Australia.

The rate for the 2012 second quarter differs from the U.S. federal statutory rate of 35% primarily due to an $8 discrete income tax charge related to prior year U.S. taxes on certain depletable assets and a net $2 discrete income tax charge for other miscellaneous items.

The effective tax rate for the 2013 and 2012 six-month periods was 79.4% (provision on income) and 39.4% (provision on income), respectively.

The rate for the 2013 six-month period differs from the U.S. federal statutory rate of 35% primarily due to the previously mentioned $103 nondeductible charge, restructuring charges in Canada and Italy, and $10 discrete income tax charge, somewhat offset by a $19 discrete income tax benefit related to new U.S. tax legislation.

On January 2, 2013, the American Taxpayer Relief Act of 2012 was signed into law and reinstated various expired or expiring temporary business tax provisions through 2013. Two specific temporary business tax provisions that expired in 2011 and impacted Alcoa are the look-through rule for payments between related controlled foreign corporations and the research and experimentation credit. The expiration of these two provisions resulted in Alcoa recognizing a higher income tax provision of $19 in 2012. As tax law changes are accounted for in the period of enactment, Alcoa recognized the previously mentioned discrete income tax benefit in the 2013 first quarter related to the 2012 tax year to reflect the extension of these provisions.

The rate for the 2012 six-month period differs from the U.S. federal statutory rate of 35% primarily due to the previously mentioned discrete income tax charges, partially offset by foreign income taxed in lower rate jurisdictions.