Common Stock	9 Months Ended
Sep. 30, 2016
Equity [Abstract]
Common Stock	M. Common Stock – As discussed in Note A, Arconic completed a 1-for-3 Reverse Stock Split on October 5, 2016. The Reverse Stock Split reduced the number of shares of common stock outstanding from approximately 1.3 billion shares to approximately 0.4 billion shares. The number of authorized shares of common stock was also decreased from 1.8 billion to 0.6 billion shares. The par value of the common stock remained at $1.00 per share. Accordingly, Common stock and Additional capital in the Company’s Consolidated Balance Sheet at September 30, 2016 were updated to reflect a decrease and increase of $877, respectively, as if the reverse stock split occurred on September 30, 2016. This transaction is not reflected on the Statement of Consolidated Cash Flows for the nine months ended September 30, 2016 as it represents a noncash financing activity. In August 2016, Arconic retired its outstanding treasury stock consisting of approximately 76 million shares. As a result, Common stock and Additional capital were decreased by $76 and $2,563, respectively, to reflect the retirement of the treasury shares. This transaction is not reflected on the Statement of Consolidated Cash Flows for the nine months ended September 30, 2016 as it represents a noncash financing activity.

Common Stock

9 Months Ended

Sep. 30, 2016

M. Common Stock – As discussed in Note A, Arconic completed a 1-for-3 Reverse Stock Split on October 5, 2016. The Reverse Stock Split reduced the number of shares of common stock outstanding from approximately 1.3 billion shares to approximately 0.4 billion shares. The number of authorized shares of common stock was also decreased from 1.8 billion to 0.6 billion shares. The par value of the common stock remained at $1.00 per share. Accordingly, Common stock and Additional capital in the Company’s Consolidated Balance Sheet at September 30, 2016 were updated to reflect a decrease and increase of $877, respectively, as if the reverse stock split occurred on September 30, 2016. This transaction is not reflected on the Statement of Consolidated Cash Flows for the nine months ended September 30, 2016 as it represents a noncash financing activity.

In August 2016, Arconic retired its outstanding treasury stock consisting of approximately 76 million shares. As a result, Common stock and Additional capital were decreased by $76 and $2,563, respectively, to reflect the retirement of the treasury shares. This transaction is not reflected on the Statement of Consolidated Cash Flows for the nine months ended September 30, 2016 as it represents a noncash financing activity.