Debt	9 Months Ended
Sep. 30, 2013
Debt Disclosure [Abstract]
Debt	E. Debt – In May 2013, Alcoa elected to call for redemption the $422 in outstanding principal of its 6.00% Notes due July 2013 (the “Notes”) under the provisions of the Notes. The total cash paid to the holders of the called Notes was $435, which includes $12 in accrued and unpaid interest from the last interest payment date up to, but not including, the settlement date, and a $1 purchase premium. The purchase premium was recorded in Interest expense on the accompanying Statement of Consolidated Operations. This transaction was completed on June 28, 2013. At the end of 2012, Alcoa had six short-term revolving credit facilities with six different financial institutions, providing a combined capacity of $640 and expiration dates ranging from March 2013 through December 2015. One of these credit facilities ($150 capacity) was effectively terminated in March 2013 upon repayment of an existing borrowing (due to expire at the end of March 2013). Additionally, two of these facilities were set to expire in September 2013 but were extended to September 2014 ($100 capacity) and September 2015 ($100 capacity) in the third quarter of 2013. In the first quarter of 2013, Alcoa entered into three revolving credit agreements, providing a combined $425 in credit facilities, with three different financial institutions. One of these facilities replaced a $200 term loan, which Alcoa fully borrowed and repaid during the first quarter of 2013. In the second quarter of 2013, Alcoa entered into another revolving credit agreement, providing a $150 credit facility, with a different financial institution. These four new revolving credit facilities expire as follows: $75 in December 2013; $150 in February 2014; $150 in March 2014; and $200 in July 2014 (extended by one year in July 2013). In summary, at September 30, 2013, Alcoa has nine short-term revolving credit facilities, providing a combined capacity of $1,065, expiring between October 2013 and December 2015. The purpose of any borrowings under all nine arrangements is to provide working capital and for other general corporate purposes. The covenants contained in all nine arrangements are the same as Alcoa’s Five-Year Revolving Credit Agreement (see the Commercial Paper section of Note K to the Consolidated Financial Statements included in Alcoa’s 2012 Form 10-K). During the first, second, and third quarters of 2013, Alcoa fully borrowed and repaid $625, $575, and $325, respectively, under these credit arrangements (including the terminated revolving credit facility and term loan referred to above). The weighted-average interest rate and weighted-average days outstanding of the respective borrowings during the first, second, and third quarters of 2013 was 1.58%, 1.50%, and 1.58%, respectively, and 40 days, 72 days, and 66 days, respectively. Also in the first quarter of 2013, Alcoa’s subsidiary, Alumínio, borrowed and repaid a total of $52 in new loans with a weighted-average interest rate of 0.72% and a weighted-average maturity of 70 days from a financial institution. The purpose of these borrowings was to support Alumínio’s export operations.

E. Debt – In May 2013, Alcoa elected to call for redemption the $422 in outstanding principal of its 6.00% Notes due July 2013 (the “Notes”) under the provisions of the Notes. The total cash paid to the holders of the called Notes was $435, which includes $12 in accrued and unpaid interest from the last interest payment date up to, but not including, the settlement date, and a $1 purchase premium. The purchase premium was recorded in Interest expense on the accompanying Statement of Consolidated Operations. This transaction was completed on June 28, 2013.

At the end of 2012, Alcoa had six short-term revolving credit facilities with six different financial institutions, providing a combined capacity of $640 and expiration dates ranging from March 2013 through December 2015. One of these credit facilities ($150 capacity) was effectively terminated in March 2013 upon repayment of an existing borrowing (due to expire at the end of March 2013). Additionally, two of these facilities were set to expire in September 2013 but were extended to September 2014 ($100 capacity) and September 2015 ($100 capacity) in the third quarter of 2013.

In the first quarter of 2013, Alcoa entered into three revolving credit agreements, providing a combined $425 in credit facilities, with three different financial institutions. One of these facilities replaced a $200 term loan, which Alcoa fully borrowed and repaid during the first quarter of 2013. In the second quarter of 2013, Alcoa entered into another revolving credit agreement, providing a $150 credit facility, with a different financial institution. These four new revolving credit facilities expire as follows: $75 in December 2013; $150 in February 2014; $150 in March 2014; and $200 in July 2014 (extended by one year in July 2013).

In summary, at September 30, 2013, Alcoa has nine short-term revolving credit facilities, providing a combined capacity of $1,065, expiring between October 2013 and December 2015. The purpose of any borrowings under all nine arrangements is to provide working capital and for other general corporate purposes. The covenants contained in all nine arrangements are the same as Alcoa’s Five-Year Revolving Credit Agreement (see the Commercial Paper section of Note K to the Consolidated Financial Statements included in Alcoa’s 2012 Form 10-K).

During the first, second, and third quarters of 2013, Alcoa fully borrowed and repaid $625, $575, and $325, respectively, under these credit arrangements (including the terminated revolving credit facility and term loan referred to above). The weighted-average interest rate and weighted-average days outstanding of the respective borrowings during the first, second, and third quarters of 2013 was 1.58%, 1.50%, and 1.58%, respectively, and 40 days, 72 days, and 66 days, respectively.

Also in the first quarter of 2013, Alcoa’s subsidiary, Alumínio, borrowed and repaid a total of $52 in new loans with a weighted-average interest rate of 0.72% and a weighted-average maturity of 70 days from a financial institution. The purpose of these borrowings was to support Alumínio’s export operations.