XML 12 R1.htm IDEA: XBRL DOCUMENT v3.4.0.3
Document and Entity Information - shares
3 Months Ended
Mar. 31, 2016
Apr. 22, 2016
Document and Entity Information    
Entity Registrant Name KAPSTONE PAPER & PACKAGING CORP  
Entity Central Index Key 0001325281  
Document Type 10-Q  
Document Period End Date Mar. 31, 2016  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Entity Current Reporting Status Yes  
Entity Filer Category Large Accelerated Filer  
Entity Common Stock, Shares Outstanding   96,509,838
Document Fiscal Year Focus 2016  
Document Fiscal Period Focus Q1