XML 25 R1.htm IDEA: XBRL DOCUMENT v3.2.0.727
Document and Entity Information - shares
 3 Months Ended
Mar. 31, 2015
Jun. 12, 2015
Document and Entity Information    
Entity Registrant Name COLLEGIUM PHARMACEUTICAL, INC  
Entity Central Index Key 0001267565  
Document Type 10-Q/A  
Document Period End Date Mar. 31, 2015  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Entity Current Reporting Status No  
Entity Filer Category Non-accelerated Filer  
Entity Common Stock, Shares Outstanding   20,665,597
Document Fiscal Year Focus 2015  
Document Fiscal Period Focus Q1