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On March 5, 2017, the Registrant's compensation committee certified the performance shares payout multiplier based on the level of achievement by the Registrant of a certain pre-established performance goal for 2014 through 2016."},{"field":"price","element":"transactionPricePerShare","label":"F3","text":"Shares earned upon the vesting on March 5, 2017 of certain performance shares granted to the reporting person in 2014 under the Kaiser Aluminum Corporation 2006 Equity and Performance Incentive Plan, as amended.  On March 5, 2017, the Registrant's compensation committee certified the performance shares payout multiplier based on the level of achievement by the Registrant of a certain pre-established performance goal for 2014 through 2016."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes 2,157 shares acquired pursuant to grants of restricted stock units."}],"balance_after":6259,"source":{"system":"sec-edgar","filing":"0001628280-17-002332","document":"wf-form4_148893038840353.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/811596/000162828017002332/wf-form4_148893038840353.xml","form_type":"4"}},{"id":4399022,"issuer":{"id":4302,"kind":"organization","name":"KAISER ALUMINUM CORP","symbol":"KALU"},"owners":[{"id":50918,"kind":"person","name":"West Neal E","position":1,"cik":"0001330319","reported_name":"West Neal E","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"VP & Chief Accounting Officer"}}],"security":"Common Stock, par value $0.01 per share","published_at":"2017-03-07T23:46:41.000Z","date":"2017-03-05","kind":"grant","acquired":true,"shares":1052,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Grant to the reporting person effective as of March 5, 2017 of restricted stock units under the Kaiser Aluminum Corporation 2016 Equity and Incentive Compensation Plan. All restrictions will lapse on March 5, 2020 or earlier upon the occurrence of certain specified circumstances."},{"field":"price","element":"transactionPricePerShare","label":"F1","text":"Grant to the reporting person effective as of March 5, 2017 of restricted stock units under the Kaiser Aluminum Corporation 2016 Equity and Incentive Compensation Plan. All restrictions will lapse on March 5, 2020 or earlier upon the occurrence of certain specified circumstances."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes 2,157 shares acquired pursuant to grants of restricted stock units."}],"balance_after":4478,"source":{"system":"sec-edgar","filing":"0001628280-17-002332","document":"wf-form4_148893038840353.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/811596/000162828017002332/wf-form4_148893038840353.xml","form_type":"4"}}]}