Collaboration and license agreements - Narrative (Details) $ / shares in Units, $ in Thousands				1 Months Ended							3 Months Ended		40 Months Ended
	May 02, 2024 USD ($)	Mar. 31, 2024 USD ($) performanceObligation target	May 29, 2023 USD ($) $ / shares shares	Apr. 30, 2024 USD ($)	Jan. 31, 2024 USD ($)	Aug. 31, 2021 USD ($)	Nov. 30, 2020 USD ($) target	Feb. 29, 2020 USD ($) protein	Dec. 31, 2018 USD ($) target performanceObligation	Mar. 31, 2017 USD ($)	Mar. 31, 2024 USD ($) performanceObligation target	Mar. 31, 2023 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2023 USD ($) target	Dec. 11, 2023 USD ($) target performanceObligation
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of performance obligations | performanceObligation									12
Contract with customer, liability		$ 55,848									$ 55,848			$ 37,285
Revenue from collaboration agreements											3,039	$ 3,759
Revenue recognized that was included in the contract liability at the beginning of the period											2,744	3,231
Transaction price allocated to performance obligation		$ 19,064									19,064
Foreign Tax Authority
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Payments for tax withholdings											$ 1,200
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]
Number of performance obligations | performanceObligation		2									2
Contract with customer, liability		$ 16,000									$ 16,000
Revenue from collaboration agreements											55	0
MKDG Agreement | Discovery, Regulatory, and Commercial Milestones
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount eligible to receive		$ 740,000									740,000
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
Number of performance obligations | performanceObligation															1
Contract with customer, liability		$ 9,355									9,355			10,000
Option to include number of additional targets | target															3
Potential proceeds from collaboration															$ 2,500,000
Revenue from collaboration agreements											645	$ 0
Merck Agreement | Research and development milestones
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount eligible to receive															$ 600,000
Merck Agreement | Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Written notice period for termination of agreement		60 days
Betta Agreements
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment			$ 10,000								15,800
Contract with customer, liability		$ 17,000									$ 17,000			$ 12,000
Stock repurchase program, number of shares authorized to be repurchased (in shares) | shares			5,567,928
Stock repurchase program, authorized amount			$ 25,000
Share price (in dollars per share) | $ / shares			$ 4.49
Transaction price from closing of the stock purchase agreement		5,000
Regulatory milestone achieved		$ 2,000
Stock repurchase program, premium percentage			25.00%
Betta Agreements | Research and development milestones
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount eligible to receive			$ 357,000
Betta Agreements | Drug Application Approval
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount eligible to receive			$ 40,000
Restated Roche Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of targets | target							2							2
Additional upfront consideration received									$ 40,000
Number of potential targets | target							5		6
Annual research plan payments receivables							$ 1,000
Option exercise fees							$ 8,000
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
Restated Roche Agreement | Maximum | One-time sales-based payments
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount eligible to receive							150,000
Restated Roche Agreement | Lead series identification achievement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront fees							$ 2,000
Biogen Research and License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of targets | performanceObligation		5									5
Research agreement, period								54 months
Nonrefundable upfront payment								$ 45,000
Number of performance obligation | performanceObligation		1									1
Biogen Research and 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
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
Biogen Research and License Agreement | Maximum | One-time sales-based payments
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Payment received								$ 26,000
Calico License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment													$ 5,000
Research term										5 years
Research extend term						1 year
Amount payable for extend research term option						$ 1,000
Annual payments													$ 5,000
Calico License Agreement | Maximum | One-time sales-based payments
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Payment received										$ 65,000
Calico License Agreement | Maximum | Potential research, development and commercial milestone payments
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Payment received										$ 132,000
Restated Roche Agreement And Biogen License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Transaction price allocated to performance obligation		$ 59,900									$ 59,900
Subsequent event | MKDG Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Upfront payment	$ 16,000
Subsequent event | Biogen Research and License Agreement
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue recognized that was included in the contract liability at the beginning of the period				$ 8,000