Debt	9 Months Ended
Sep. 30, 2014
Debt Disclosure [Abstract]
Debt	G. Debt – In the first quarter of 2014, holders of $575 principal amount of Alcoa’s 5.25% Convertible Notes due March 15, 2014 (the “Notes”) exercised their option to convert the Notes into 89 million shares of Alcoa common stock. The conversion rate for the Notes was 155.4908 shares of Alcoa’s common stock per $1,000 (in full dollars) principal amount of notes, equivalent to a conversion price of $6.43 per share. The difference between the $575 principal amount of the Notes and the $89 par value of the issued shares increased Additional capital on the accompanying Consolidated Balance Sheet. This transaction was not reflected in the accompanying Statement of Consolidated Cash Flows as it represents a noncash financing activity. In September 2014, Alcoa completed a public debt offering under its shelf registration statement for $1,250 of 5.125% Notes due 2024 (the “2024 Notes”). Alcoa received $1,238 in net proceeds from the public debt offering reflecting an original issue discount. The net proceeds are intended to be used, together with the net proceeds of newly issued mandatory convertible preferred stock (see Note K), to finance the cash portion of a planned acquisition of an aerospace business (see Note E). The original issue discount was deferred and is being amortized to interest expense over the term of the 2024 Notes. Interest on the 2024 Notes will be paid semi-annually in April and October, commencing April 2015. If the acquisition is not consummated on or prior to 5:00 p.m. (New York City time) on April 1, 2015 or if prior to this stated date and time, the share purchase agreement related to the acquisition is terminated other than in connection with the consummation of the acquisition and is not otherwise amended or replaced, Alcoa is required to redeem the 2024 Notes, in whole but not in part, at a redemption price in cash equal to 101% of the aggregate principal amount of the 2024 Notes, plus any accrued and unpaid interest on the 2024 Notes. Separately, Alcoa has the option to redeem the 2024 Notes, as a whole or in part, at any time or from time to time, on at least 30 days, but not more than 60 days, prior notice to the holders of the 2024 Notes at a redemption price specified in the 2024 Notes. The 2024 Notes are subject to repurchase upon the occurrence of a change in control repurchase event (as defined in the 2024 Notes) at a repurchase price in cash equal to 101% of the aggregate principal amount of the 2024 Notes repurchased, plus any accrued and unpaid interest on the 2024 Notes repurchased. The 2024 Notes rank pari passu with Alcoa’s other unsecured unsubordinated indebtedness. On July 25, 2014, Alcoa entered into a Five-Year Revolving Credit Agreement (the “Credit Agreement”) with a syndicate of lenders and issuers named therein. The Credit Agreement provides a $4,000 senior unsecured revolving credit facility (the “Credit Facility”), the proceeds of which are to be used to provide working capital or for other general corporate purposes of Alcoa. Subject to the terms and conditions of the Credit Agreement, Alcoa may from time to time request increases in lender commitments under the Credit Facility, not to exceed $500 in aggregate principal amount, and may also request the issuance of letters of credit, subject to a letter of credit sublimit of $1,000 under the Credit Facility. The Credit Facility matures on July 25, 2019, unless extended or earlier terminated in accordance with the provisions of the Credit Agreement. Alcoa may make two one-year extension requests during the term of the Credit Facility, with any extension being subject to the lender consent requirements set forth in the Credit Agreement. Under the provisions of the Credit Agreement, Alcoa will pay a fee of 0.25% (based on Alcoa’s long-term debt ratings as of September 30, 2014) of the total commitment per annum to maintain the Credit Facility. The Credit Facility is unsecured and amounts payable under it will rank pari passu with all other unsecured, unsubordinated indebtedness of Alcoa. Borrowings under the Credit Facility may be denominated in U.S. dollars or euros. Loans will bear interest at a base rate or a rate equal to LIBOR, plus, in each case, an applicable margin based on the credit ratings of Alcoa’s outstanding senior unsecured long-term debt. The applicable margin on base rate loans and LIBOR loans will be 0.50% and 1.50% per annum, respectively, based on Alcoa’s long-term debt ratings as of September 30, 2014. Loans may be prepaid without premium or penalty, subject to customary breakage costs. The Credit Facility replaces Alcoa’s Five-Year Revolving Credit Agreement, dated as of July 25, 2011 (the “Former Credit Agreement”), which was scheduled to mature on July 25, 2017. The Former Credit Agreement, which had a total capacity of $3,750 and was undrawn, was terminated effective July 25, 2014. The Credit Agreement includes covenants substantially similar to those in the Former Credit Agreement, including, among others, (a) a leverage ratio, (b) limitations on Alcoa’s ability to incur liens securing indebtedness for borrowed money, (c) limitations on Alcoa’s ability to consummate a merger, consolidation or sale of all or substantially all of its assets, and (d) limitations on Alcoa’s ability to change the nature of its business. As of September 30, 2014, Alcoa was in compliance with all such covenants. The obligation of Alcoa to pay amounts outstanding under the Credit Facility may be accelerated upon the occurrence of an “Event of Default” as defined in the Credit Agreement. Such Events of Default include, among others, (a) Alcoa’s failure to pay the principal of, or interest on, borrowings under the Credit Facility, (b) any representation or warranty of Alcoa in the Credit Agreement proving to be materially false or misleading, (c) Alcoa’s breach of any of its covenants contained in the Credit Agreement, and (d) the bankruptcy or insolvency of Alcoa. There were no amounts outstanding under the Credit Facility at September 30, 2014 and no amounts were borrowed during the 2014 third quarter under the Credit Facility. At the end of 2013, Alcoa had ten revolving credit facilities (excluding the Credit Facility above), each with a different financial institution, providing a combined capacity of $1,190 and expiration dates ranging from February 2014 through December 2015. A credit facility ($150 capacity) that was due to expire in February 2014 was extended to March 2015 in the first quarter of 2014. Another credit facility ($150 capacity) expired in March 2014 (a new agreement with the same financial institution was entered into in April 2014 and the new facility expires in March 2016). Also in the first quarter of 2014, Alcoa entered into an eleventh revolving credit agreement, providing a $50 credit facility with an expiration date of February 2016. In the third quarter of 2014, two credit facilities ($200 combined capacity) that were due to expire in September 2014 and October 2014 were extended to September 2016 and October 2015, respectively. Additionally in the third quarter of 2014, a $200 credit facility expired and was not extended or renewed. In summary, at September 30, 2014, Alcoa has ten revolving credit facilities (excluding the Credit Facility), providing a combined capacity of $1,040, of which $340, $400, and $300 is due to expire in the remainder of 2014, 2015, and 2016, respectively. The purpose of any borrowings under all of these credit arrangements is to provide for working capital requirements and for other general corporate purposes. The covenants contained in all these arrangements are the same as the Credit Agreement above. During the first, second, and third quarters of 2014, Alcoa borrowed and repaid $620, $510, and $510, respectively, under these credit arrangements. The weighted-average interest rate and weighted-average days outstanding of the respective borrowings during the first, second, and third quarters of 2014 were 1.53%, 1.55%, and 1.55%, respectively, and 49 days, 84 days, and 73 days, respectively.

G. Debt – In the first quarter of 2014, holders of $575 principal amount of Alcoa’s 5.25% Convertible Notes due March 15, 2014 (the “Notes”) exercised their option to convert the Notes into 89 million shares of Alcoa common stock. The conversion rate for the Notes was 155.4908 shares of Alcoa’s common stock per $1,000 (in full dollars) principal amount of notes, equivalent to a conversion price of $6.43 per share. The difference between the $575 principal amount of the Notes and the $89 par value of the issued shares increased Additional capital on the accompanying Consolidated Balance Sheet. This transaction was not reflected in the accompanying Statement of Consolidated Cash Flows as it represents a noncash financing activity.

In September 2014, Alcoa completed a public debt offering under its shelf registration statement for $1,250 of 5.125% Notes due 2024 (the “2024 Notes”). Alcoa received $1,238 in net proceeds from the public debt offering reflecting an original issue discount. The net proceeds are intended to be used, together with the net proceeds of newly issued mandatory convertible preferred stock (see Note K), to finance the cash portion of a planned acquisition of an aerospace business (see Note E). The original issue discount was deferred and is being amortized to interest expense over the term of the 2024 Notes. Interest on the 2024 Notes will be paid semi-annually in April and October, commencing April 2015. If the acquisition is not consummated on or prior to 5:00 p.m. (New York City time) on April 1, 2015 or if prior to this stated date and time, the share purchase agreement related to the acquisition is terminated other than in connection with the consummation of the acquisition and is not otherwise amended or replaced, Alcoa is required to redeem the 2024 Notes, in whole but not in part, at a redemption price in cash equal to 101% of the aggregate principal amount of the 2024 Notes, plus any accrued and unpaid interest on the 2024 Notes. Separately, Alcoa has the option to redeem the 2024 Notes, as a whole or in part, at any time or from time to time, on at least 30 days, but not more than 60 days, prior notice to the holders of the 2024 Notes at a redemption price specified in the 2024 Notes. The 2024 Notes are subject to repurchase upon the occurrence of a change in control repurchase event (as defined in the 2024 Notes) at a repurchase price in cash equal to 101% of the aggregate principal amount of the 2024 Notes repurchased, plus any accrued and unpaid interest on the 2024 Notes repurchased. The 2024 Notes rank pari passu with Alcoa’s other unsecured unsubordinated indebtedness.

On July 25, 2014, Alcoa entered into a Five-Year Revolving Credit Agreement (the “Credit Agreement”) with a syndicate of lenders and issuers named therein. The Credit Agreement provides a $4,000 senior unsecured revolving credit facility (the “Credit Facility”), the proceeds of which are to be used to provide working capital or for other general corporate purposes of Alcoa. Subject to the terms and conditions of the Credit Agreement, Alcoa may from time to time request increases in lender commitments under the Credit Facility, not to exceed $500 in aggregate principal amount, and may also request the issuance of letters of credit, subject to a letter of credit sublimit of $1,000 under the Credit Facility.

The Credit Facility matures on July 25, 2019, unless extended or earlier terminated in accordance with the provisions of the Credit Agreement. Alcoa may make two one-year extension requests during the term of the Credit Facility, with any extension being subject to the lender consent requirements set forth in the Credit Agreement. Under the provisions of the Credit Agreement, Alcoa will pay a fee of 0.25% (based on Alcoa’s long-term debt ratings as of September 30, 2014) of the total commitment per annum to maintain the Credit Facility.

The Credit Facility is unsecured and amounts payable under it will rank pari passu with all other unsecured, unsubordinated indebtedness of Alcoa. Borrowings under the Credit Facility may be denominated in U.S. dollars or euros. Loans will bear interest at a base rate or a rate equal to LIBOR, plus, in each case, an applicable margin based on the credit ratings of Alcoa’s outstanding senior unsecured long-term debt. The applicable margin on base rate loans and LIBOR loans will be 0.50% and 1.50% per annum, respectively, based on Alcoa’s long-term debt ratings as of September 30, 2014. Loans may be prepaid without premium or penalty, subject to customary breakage costs.

The Credit Facility replaces Alcoa’s Five-Year Revolving Credit Agreement, dated as of July 25, 2011 (the “Former Credit Agreement”), which was scheduled to mature on July 25, 2017. The Former Credit Agreement, which had a total capacity of $3,750 and was undrawn, was terminated effective July 25, 2014.

The Credit Agreement includes covenants substantially similar to those in the Former Credit Agreement, including, among others, (a) a leverage ratio, (b) limitations on Alcoa’s ability to incur liens securing indebtedness for borrowed money, (c) limitations on Alcoa’s ability to consummate a merger, consolidation or sale of all or substantially all of its assets, and (d) limitations on Alcoa’s ability to change the nature of its business. As of September 30, 2014, Alcoa was in compliance with all such covenants.

The obligation of Alcoa to pay amounts outstanding under the Credit Facility may be accelerated upon the occurrence of an “Event of Default” as defined in the Credit Agreement. Such Events of Default include, among others, (a) Alcoa’s failure to pay the principal of, or interest on, borrowings under the Credit Facility, (b) any representation or warranty of Alcoa in the Credit Agreement proving to be materially false or misleading, (c) Alcoa’s breach of any of its covenants contained in the Credit Agreement, and (d) the bankruptcy or insolvency of Alcoa.

There were no amounts outstanding under the Credit Facility at September 30, 2014 and no amounts were borrowed during the 2014 third quarter under the Credit Facility.

At the end of 2013, Alcoa had ten revolving credit facilities (excluding the Credit Facility above), each with a different financial institution, providing a combined capacity of $1,190 and expiration dates ranging from February 2014 through December 2015.

A credit facility ($150 capacity) that was due to expire in February 2014 was extended to March 2015 in the first quarter of 2014. Another credit facility ($150 capacity) expired in March 2014 (a new agreement with the same financial institution was entered into in April 2014 and the new facility expires in March 2016). Also in the first quarter of 2014, Alcoa entered into an eleventh revolving credit agreement, providing a $50 credit facility with an expiration date of February 2016.

In the third quarter of 2014, two credit facilities ($200 combined capacity) that were due to expire in September 2014 and October 2014 were extended to September 2016 and October 2015, respectively. Additionally in the third quarter of 2014, a $200 credit facility expired and was not extended or renewed.

In summary, at September 30, 2014, Alcoa has ten revolving credit facilities (excluding the Credit Facility), providing a combined capacity of $1,040, of which $340, $400, and $300 is due to expire in the remainder of 2014, 2015, and 2016, respectively.

The purpose of any borrowings under all of these credit arrangements is to provide for working capital requirements and for other general corporate purposes. The covenants contained in all these arrangements are the same as the Credit Agreement above.

During the first, second, and third quarters of 2014, Alcoa borrowed and repaid $620, $510, and $510, respectively, under these credit arrangements. The weighted-average interest rate and weighted-average days outstanding of the respective borrowings during the first, second, and third quarters of 2014 were 1.53%, 1.55%, and 1.55%, respectively, and 49 days, 84 days, and 73 days, respectively.