v2.4.0.8
Document and Entity Information
3 Months Ended
Mar. 31, 2015
Apr. 27, 2015
Document and Entity Information [Abstract]    
Entity Registrant Name Kaiser Aluminum Corp  
Entity Central Index Key 0000811596  
Document Type 10-Q  
Document Period End Date Mar. 31, 2015  
Amendment Flag false  
Document Fiscal Year Focus 2015  
Document Fiscal Period Focus Q1  
Current Fiscal Year End Date --12-31  
Entity Filer Category Large Accelerated Filer  
Entity Common Stock, Shares Outstanding   17,154,172