Collaboration and License Agreements - Revenue Recognized (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended		12 Months Ended		24 Months Ended
	Aug. 01, 2022	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2021	Dec. 31, 2018	Dec. 31, 2020
Revenues
Revenue		$ 56,566	$ 65,977	$ 177,423	$ 165,255
License | Related Party
Revenues
Revenue			27,500		27,500
License | IDRx, Inc. | Director
Revenues
Revenue	$ 27,500
Collaborative Arrangement | Zai Lab (Shanghai) Co., Ltd.
Revenues
Revenue						$ 25,000
Collaborative Arrangement | Clementia
Revenues
Revenue		0			30,000			$ 46,500
Collaborative Arrangement | Collaboration revenue | Roche, Collaboration (Pralsetnib) Agreement
Revenues
Revenue		513	4,282	1,672	5,573
Collaborative Arrangement | Collaboration revenue | Roche, Collaboration and License (Immunotherapy) Agreement
Revenues
Revenue		0	2,500	25,700	1,700
Cumulative revenue catch-up				9,700
Collaborative Arrangement | Collaboration revenue | C Stone
Revenues
Revenue		1,820	2,915	16,861	18,209		$ 40,000
Collaborative Arrangement | License milestone revenue | C Stone
Revenues
Revenue		0	0	9,000	4,000
Collaborative Arrangement | Territory-specific activities | Zai Lab (Shanghai) Co., Ltd.
Revenues
Revenue			200		800
Collaborative Arrangement | Territory-specific activities, manufacturing services and royalty | C Stone
Revenues
Revenue		1,820	2,915	7,861	14,209
Collaborative Arrangement | Territory-specific activities, manufacturing and research and development services | Roche, Collaboration (Pralsetnib) Agreement
Revenues
Revenue		213	3,971	570	4,663
Collaborative Arrangement | Royalty | Roche, Collaboration (Pralsetnib) Agreement
Revenues
Revenue		$ 300	$ 311	$ 1,102	$ 910