v3.7.0.1
Document and Entity Information - USD ($)
12 Months Ended
Dec. 31, 2016
Jun. 05, 2017
Jun. 30, 2016
Document And Entity Information [Abstract]      
Document Type 10-K/A    
Amendment Flag true    
Amendment Description Cerulean Pharma Inc. (the “Company”) is filing this Amendment No. 2 on Form 10-K/A (the “Amendment”) to its Annual Report on Form 10-K for the fiscal year ended December 31, 2016, originally filed with the Securities and Exchange Commission on March 31, 2017 (the “Original 10-K”) and amended by that certain Amendment No. 1 on Form 10-K/A filed on April 28, 2017 (“Amendment No. 1” and together with the Original 10-K, the “Annual Report”). This Amendment is being filed to include revised certifications of the Company’s principal executive officer and principal financial officer in Exhibits 31.1 and 31.2, which replace the versions of those certifications that were previously filed as Exhibits 31.1 and 31.2 to the Original 10-K and as Exhibits 31.3 and 31.4 to Amendment No. 1, to add language regarding internal control over financial reporting that was inadvertently omitted from such previously filed certifications. Each certification, as corrected by this Amendment, was true and correct as of the filing date of each of the Original 10-K and Amendment No. 1. In addition, this Amendment is being filed to include the existing employment agreements between the Company and one of its named executive officers for the fiscal year ended December 31, 2016, Scott Eliasof, who serves as Senior Vice President and Chief Scientific Officer of the Company. In accordance with Rule 12b-15 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), Part II, Items 8 and 9A of the Annual Report are hereby restated in their entirety without material change, and Part IV, Item 15 of the Annual Report is hereby amended and restated in its entirety, with the only changes to Part IV, Item 15 being the addition of Dr. Eliasof’s existing employment agreements, an updated consent from Deloitte & Touche LLP, new certifications by our principal executive officer and principal financial officer filed herewith and updated XBRL exhibits. Except as otherwise expressly set forth in this Amendment, no portion of the Annual Report is being amended or updated by this Amendment. Accordingly, this Amendment should be read in conjunction with the Annual Report and with our filings with the Securities and Exchange Commission subsequent to the Annual Report. Unless we specify otherwise, all references in this Amendment to “we,” “our,” “us,” or “the Company” refer to Cerulean Pharma Inc.    
Document Period End Date Dec. 31, 2016    
Document Fiscal Year Focus 2016    
Document Fiscal Period Focus FY    
Trading Symbol CERU    
Entity Registrant Name CERULEAN PHARMA INC.    
Entity Central Index Key 0001401914    
Current Fiscal Year End Date --12-31    
Entity Well-known Seasoned Issuer No    
Entity Current Reporting Status Yes    
Entity Voluntary Filers No    
Entity Filer Category Non-accelerated Filer    
Entity Common Stock, Shares Outstanding   29,031,728  
Entity Public Float     $ 47,569,338