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			9 Months Ended		12 Months Ended
	Mar. 31, 2021 USD ($)	May 31, 2019 USD ($)	Jun. 30, 2022 USD ($) Program PerformanceObligation	Apr. 30, 2022 USD ($)	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 ($) Program	Aug. 31, 2017 Program	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Accounts receivable, reserve for credit losses					$ 0								$ 0			$ 0		$ 0
BioNova Option Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue													0			0
Initial licensing option payment						$ 4,000,000.0							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		0
2018 BMS Master Services Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue					600,000								2,100,000			2,100,000		600,000
2018 Merck Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue					900,000								0			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
Contingent payment received													10,000,000.0
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		0
MDA Agreement \| EMD Serono
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue					0								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								500,000			500,000		0
Supply Agreement \| Vaxcyte, Inc.
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Reimbursements expenses													4,000,000.0	$ 3,900,000		10,200,000	$ 4,900,000
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				$ 350,000,000.0	345,000,000													345,000,000
Reduction of research and development expenses recognized													0			0
Upfront payment revenue not recognized					40,000,000.0
Initial licensing payment due				25,000,000.0
Initial licensing payment in escrow				$ 15,000,000.0
Upfront payment revenue recognized																25,000,000.0
Upfront payment withholding tax amount																2,500,000
Astellas License and Collaboration Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Deferred revenue					$ 0								88,100,000			88,100,000		$ 0
Number of target programs \| Program			3
Upfront payment received																90,000,000.0
Transaction price			$ 90,000,000.0
Estimated service period			4 years
Recognition of up front payment			$ 89,100,000
Upfront payment revenue not recognized																29,200,000
Nonrefundable, non-creditable upfront payment receivable													90,000,000.0			90,000,000.0
Number of performance obligations \| PerformanceObligation			4
Maximum amount eligible to receive for development, regulatory and commercial milestones for each product candidate													$ 422,500,000			$ 422,500,000
Termination written notice period			30 days
Astellas License and Collaboration Agreement \| Future Services on Collaboration Joint Steering Committee ("JSC")
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Recognition of up front payment			$ 900,000