Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2022	Mar. 06, 2023	Jun. 30, 2022
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2022
Document Transition Report	false
Entity File Number	001-38459
Entity Registrant Name	SURFACE ONCOLOGY, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	46-5543980
Entity Address, Address Line One	50 Hampshire Street
Entity Address, Address Line Two	8th Floor
Entity Address, City or Town	Cambridge
Entity Address, State or Province	MA
Entity Address, Postal Zip Code	02139
City Area Code	617
Local Phone Number	714-4096
Title of 12(b) Security	Common stock, $0.0001
Trading Symbol	SURF
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Public Float			$ 85,420,850
Entity Common Stock, Shares Outstanding		60,716,873
Documents Incorporated by Reference	Portions of the registrant’s Definitive Proxy Statement relating to the Annual Meeting of Shareholders, scheduled to be held on June 7, 2023, are incorporated by reference into Part III of this Report.
Entity Central Index Key	0001718108
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	FY
Amendment Flag	false