XML 12 R1.htm IDEA: XBRL DOCUMENT v3.23.3
Document and Entity Information - shares
 9 Months Ended
Sep. 30, 2023
Oct. 31, 2023
Document and Entity Information    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Sep. 30, 2023  
Document Transition Report false  
Entity File Number 001-37372  
Entity Registrant Name Collegium Pharmaceutical, Inc.  
Entity Incorporation, State or Country Code VA  
Entity Tax Identification Number 03-0416362  
Entity Address, Address Line One 100 Technology Center Drive  
Entity Address, City or Town Stoughton  
Entity Address, State or Province MA  
Entity Address, Postal Zip Code 02072  
City Area Code 781  
Local Phone Number 713-3699  
Title of 12(b) Security Common Stock  
Trading Symbol COLL  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   32,610,873
Entity Central Index Key 0001267565  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2023  
Document Fiscal Period Focus Q3  
Amendment Flag false