Sutro Biopharma, Inc. Quarterly report pursuant to Section 13 or 15(d)

Subsequent Events - Additional Information (Details) - USD ($) $ in Millions		1 Months Ended	3 Months Ended	12 Months Ended
	Jul. 26, 2022	Aug. 05, 2022	Jun. 30, 2022	Dec. 31, 2021
2018 Merck Agreement \| Merck Sharp & Dohme Corp
Subsequent Event [Line Items]
Milestone payment received				$ 2.5
Common Stock \| ATM
Subsequent Event [Line Items]
Shares of common stock			1,716,996
Net proceeds from issuance of common stock			$ 8.2
Subsequent Event \| 2018 Merck Agreement \| Merck Sharp & Dohme Corp
Subsequent Event [Line Items]
Milestone payment received	$ 10.0
Subsequent Event \| Common Stock \| ATM
Subsequent Event [Line Items]
Shares of common stock		3,518,619
Net proceeds from issuance of common stock		$ 19.9