Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2019	Jul. 26, 2019
Document And Entity Information [Abstract]
Entity Registrant Name	SYROS PHARMACEUTICALS, INC.
Trading Symbol	SYRS
Entity Central Index Key	0001556263
Document Type	10-Q
Document Period End Date	Jun. 30, 2019
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		42,438,244
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
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	453772460
Entity Address, Address Line One	620 Memorial Drive
Entity Address, Address Line Two	Suite 300
Entity Address, City or Town	Cambridge
Entity Address, State or Province	Massachusetts
Entity Address, Postal Zip Code	02139
City Area Code	(617)
Local Phone Number	744-1340