Collaboration and license agreements - Narrative (Details) $ / shares in Units, $ in Thousands					1 Months Ended						3 Months Ended		6 Months Ended		40 Months Ended
	Jun. 30, 2024 USD ($) performanceObligation target	Mar. 01, 2024 USD ($) target	Dec. 11, 2023 USD ($) target performanceObligation	May 29, 2023 USD ($) $ / shares shares	Apr. 30, 2024 USD ($)	Aug. 31, 2021 USD ($)	Nov. 30, 2020 USD ($) target	Feb. 29, 2020 USD ($) protein	Dec. 31, 2018 USD ($) target performanceObligation	Mar. 31, 2017 USD ($)	Jun. 30, 2024 USD ($) performanceObligation target	Jun. 30, 2023 USD ($)	Jun. 30, 2024 USD ($) performanceObligation target	Jun. 30, 2023 USD ($)	Jun. 30, 2020 USD ($)	Dec. 31, 2023 USD ($) target
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Number of performance obligations | performanceObligation									12
Contract with customer, liability	$ 53,502										$ 53,502		$ 53,502			$ 37,285
Revenue from collaboration agreements											12,006	$ 2,664	15,045	$ 6,423
Revenue recognized that was included in the contract liability at the beginning of the period											2,065	2,664	5,003	5,895
Transaction price allocated to performance obligation	$ 19,064										$ 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									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
Number of performance obligations | performanceObligation	2										2		2
Contract with customer, liability	$ 15,219										$ 15,219		$ 15,219
Revenue from collaboration agreements											1,894	0	1,949	0
Transaction price allocated to performance obligation	16,000										16,000		16,000
MKDG Agreement | Discovery, Regulatory, and Commercial Milestones
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Amount eligible to receive	740,000										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	8,253										8,253		8,253			10,000
Option to include number of additional targets | target			3
Potential proceeds from collaboration			$ 2,500,000
Revenue from collaboration agreements											1,102	$ 0	1,747	$ 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			$ 10,000									15,800
Contract with customer, liability	17,000										$ 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%
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
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		5
Research agreement, period								54 months
Nonrefundable upfront payment								$ 45,000
Revenue recognized that was included in the contract liability at the beginning of the period					$ 8,000
Number of performance obligation | performanceObligation	1										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	$ 57,100										$ 57,100		$ 57,100