Collaboration and license agreements - Narrative (Details)					1 Months Ended								12 Months Ended		40 Months Ended
	Sep. 30, 2024 USD ($)	Mar. 01, 2024 USD ($) target	Dec. 11, 2023 USD ($) performanceObligation target	May 29, 2023 USD ($) $ / shares shares	Sep. 30, 2024 USD ($)	Apr. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)	Aug. 31, 2021 USD ($)	Nov. 30, 2020 USD ($) target	Feb. 29, 2020 USD ($) protein	Dec. 31, 2018 USD ($) performanceObligation target	Mar. 31, 2017 USD ($)	Dec. 31, 2024 USD ($) target performanceObligation	Dec. 31, 2023 USD ($)	Jun. 30, 2020 USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of performance obligations | performanceObligation											12
Transaction price allocated to performance obligation													$ 19,064,000
Contract with customer, liability							$ 37,285,000						47,169,000	$ 37,285,000
Revenue from collaboration agreements													35,584,000	20,756,000
Revenue recognized that was included in the contract liability at the beginning of the period													$ 12,184,000	20,185,000
MKDG Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of potential research and development targets | target		2											2
Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Written notice period for termination of agreement				90 days
MKDG Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment		$ 16,000,000
Number of performance obligations | performanceObligation													2
Transaction price allocated to performance obligation													$ 16,000,000
Contract with customer, liability													13,373,000
Revenue from collaboration agreements													7,304,000	0
MKDG Agreement | Discovery, Regulatory, and Commercial Milestones
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount eligible to receive		$ 740,000,000
MKDG Agreement | Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Written notice period for termination of agreement		60 days
Merck Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment			$ 10,000,000.0
Number of performance obligations | performanceObligation			1
Contract with customer, liability							10,000,000						6,022,000	10,000,000
Option to include number of additional targets | target			3
Potential proceeds from collaboration			$ 2,500,000,000
Revenue from collaboration agreements													3,979,000	0
Merck Agreement | Research and development milestones
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount eligible to receive			$ 600,000,000
Merck Agreement | Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Written notice period for termination of agreement			60 days
Betta Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment	$ 10,000,000			$ 10,000,000.0										1,000,000
Contract with customer, liability							12,000,000						15,281,000	12,000,000
Number of shares (in shares) | shares				5,567,928
Consideration received on transaction				$ 25,000,000.0
Price per share (in dollars per share) | $ / shares				$ 4.49
Premium percentage				25.00%
Duration of trading day volume weighted average closing price				60 days
Trading days prior to the effective date of the stock purchase agreement				2 days
Proceeds from issuance of common stock													20,000,000
Premium from issuance of common stock													5,000,000
Estimated transaction price													135,500,000
Transaction price from closing of the stock purchase agreement	$ 5,000,000
Regulatory milestone achieved							$ 2,000,000
Expected consideration to be received from manufactured clinical supply													118,500,000
Revenue from collaboration agreements													$ 3,415,000	$ 0
Betta Agreement | Research and development milestones
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount eligible to receive				$ 357,000,000.0
Betta Agreement | Drug Application Approval
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount eligible to receive				$ 40,000,000.0
Restated Roche Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Additional upfront consideration received											$ 40,000,000
Number of potential targets | target									5		6
Number of targets | target									2				2
Option exercise fees									$ 8,000,000.0
Annual research plan payments receivables									1,000,000
Restated Roche Agreement | Lead series identification achievement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront fees									2,000,000
Restated Roche Agreement | Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Written notice period for termination of agreement													90 days
Restated Roche Agreement | Maximum | Research, development and commercial milestone payments
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount eligible to receive									273,000,000
Restated Roche Agreement | Maximum | One-time sales-based payments
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount eligible to receive									$ 150,000,000
Biogen Research and License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Research agreement, period										54 months
Nonrefundable upfront payment										$ 45,000,000
Revenue recognized that was included in the contract liability at the beginning of the period					$ 8,000,000	$ 8,000,000
Biogen Research and License Agreement | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of targeted protein degradation | protein										5
Biogen Research and License Agreement | Maximum | Research and development milestones
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Payment received										$ 35,000,000
Biogen Research and License Agreement | Maximum | One-time sales-based payments
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Payment received										$ 26,000,000
Biogen License Agreement | Research and development services
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized that was included in the contract liability at the beginning of the period													$ 55,000,000.0
Calico License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment															$ 5,000,000
Research term												5 years
Research extend term								1 year
Annual payments															$ 5,000,000
Amount payable for extend research term option								$ 1,000,000
Calico License Agreement | Maximum | One-time sales-based payments
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Payment received												$ 65,000,000
Calico License Agreement | Maximum | Potential research, development and commercial milestone payments
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Payment received												$ 132,000,000
Calico License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Transaction price allocated to performance obligation													$ 166,500,000