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

Quarterly report pursuant to Section 13 or 15(d)

Collaboration and License Agreements and Supply Agreements - Additional Information (Details)

Collaboration and License Agreements and Supply Agreements - Additional Information (Details)			1 Months Ended								3 Months Ended			12 Months Ended
	Mar. 31, 2021 USD ($)	May 31, 2019 USD ($)	Dec. 31, 2021 USD ($)	Oct. 31, 2021 USD ($)	Aug. 31, 2020 USD ($)	Mar. 31, 2020 USD ($)	Feb. 29, 2020 USD ($)	Sep. 30, 2019 USD ($)	Jul. 31, 2018 USD ($) Program	Aug. 31, 2017 Program	Mar. 31, 2022 USD ($)	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2021 USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Accounts receivable, reserve for credit losses			$ 0								$ 0			$ 0
Accounts receivable			12,454,000								11,686,000			12,454,000
BioNova Option Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue											4,000,000.0
Initial licensing option payment				$ 4,000,000.0
Maximum potential payments related to option exercise, development, regulatory, and commercial milestones				$ 200,000,000
Minimum term of royalties receivable based on annual net sales				10 years
Initial licensing option refundable payment				$ 4,000,000.0
Additional payment required to exercise license option				$ 12,000,000.0
BMS Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of programs advancing through preclinical development \| Program										4
Contingent payments		$ 275,000,000.0
Deferred revenue			0								0			0
2018 BMS Master Services Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue			600,000								2,300,000			600,000
2018 Merck Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue			900,000								0			900,000
Milestone payment receivable upon initiation of IND enabling toxicology study												$ 15,000,000.0
2018 Merck Agreement \| Future Services on Collaboration Joint Steering Committee ("JSC")
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Contingent payment received														15,000,000.0
Remaining contingent payment received														300,000
Revenue recognized											300,000
2018 Merck Agreement \| Merck Sharp & Dohme Corp
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of target programs \| Program									2
Initial transaction price									$ 60,000,000.0
Upfront payment received											60,000,000.0
Constrained variable consideration														7,500,000
Milestone payment received														2,500,000
Additional milestone payment received														7,500,000
Revenue recognized											$ 600,000			1,900,000
Revenue recognition aggregate contingent payments eligible to receive														500,000,000
Milestone method revenue recognition description											If one or more products from the target program is developed for non-oncology or a single indication, the Company will be eligible for reduced aggregate contingent payments. In addition, the Company is eligible to receive tiered royalties ranging from mid-single digit to low teen percentages on the worldwide sales of any commercial products that may result from the collaboration.
First Cytokine-Derivative Program \| Merck Sharp & Dohme Corp
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment received						$ 5,000,000.0
Extended research term						1 year
Transaction price	$ 65,000,000.0					$ 65,000,000.0	$ 60,000,000.0					80,000,000.0
Constrained variable consideration							$ 5,000,000.0					15,000,000.0
2020 Merck Master Services Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue			0								$ 0			0
MDA Agreement \| EMD Serono
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue			0								0			0
Contingent payment received								$ 1,500,000				$ 2,000,000.0
Milestone payment received					$ 1,000,000.0
Maximum amount eligible to receive for each product developed											52,500,000
2019 EMD Serono Supply Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue			$ 0								0			0
Supply Agreement \| Vaxcyte, Inc.
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Reimbursements expenses											2,400,000		$ 300,000
Tasly License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Minimum term of royalties receivable based on annual net sales			10 years
Nonrefundable upfront payment receivable			$ 40,000,000.0											40,000,000.0
Maximum potential payments related to development regulatory commercialization contingent payments and milestones			345,000,000											$ 345,000,000
Reduction of research and development expenses recognized											0
Upfront payment revenue not recognized			$ 40,000,000.0								$ 40,000,000.0