Quarterly report pursuant to Section 13 or 15(d)

Document and Entity Information

Document and Entity Information - shares
9 Months Ended
Sep. 30, 2020
Oct. 31, 2020
Cover [Abstract]    
Entity Registrant Name SYROS PHARMACEUTICALS, INC.  
Trading Symbol SYRS  
Entity Central Index Key 0001556263  
Document Type 10-Q  
Document Period End Date Sep. 30, 2020  
Amendment Flag false  
Current Fiscal Year End Date --12-31  
Entity Filer Category Accelerated Filer  
Entity Common Stock, Shares Outstanding   45,810,735
Document Fiscal Year Focus 2020  
Document Fiscal Period Focus Q3  
Entity Small Business true  
Entity Ex Transition Period true  
Entity Emerging Growth Company true  
Entity Current Reporting Status Yes  
Entity Shell Company false  
Entity File Number 001-37813  
Entity Tax Identification Number 45-3772460  
Entity Address, Address Line One 35 CambridgePark Drive  
Entity Address, Address Line Two 4th Floor  
Entity Address, City or Town Cambridge  
Entity Address, State or Province MA  
Entity Address, Postal Zip Code 02140  
City Area Code 617  
Local Phone Number 744-1340  
Document Quarterly Report true  
Document Transition Report false  
Entity Interactive Data Current Yes  
Entity Incorporation, State or Country Code DE  
Title of 12(b) Security Common Stock, $0.001 par value  
Security Exchange Name NASDAQ