Document and Entity Information
Mar. 10, 2022
Cover [Abstract]  
Document Type 8-K
Amendment Flag false
Document Period End Date Mar. 10, 2022
Entity Registrant Name SIERRA ONCOLOGY, INC.
Entity Central Index Key 0001290149
Entity Emerging Growth Company false
Title of 12(b) Security Common Stock, $0.001 par value
Trading Symbol SRRA
Security Exchange Name NASDAQ
Entity File Number 001-37490
Entity Incorporation State Country Code DE
Entity Tax Identification Number 20-0138994
Entity Address Address Line1 1820 Gateway Drive
Entity Address, Address Line 2 Suite 110
Entity Address City Or Town San Mateo
Entity Address State Or Province CA
Entity Address Postal Zip Code 94404
City Area Code 605
Local Phone Number 376-8679
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false