Research and Development Agreements - Schedule of Research and Development Revenue from Related Party Relates to Revenue from Research and Development Agreements (Detail)

v3.21.2

Research and Development Agreements - Schedule of Research and Development Revenue from Related Party Relates to Revenue from Research and Development Agreements (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenue Recognition [Line Items]
Total research and development revenue, related party	$ 15,134	$ 6,040	$ 18,354	$ 7,840
Takeda Development Agreement
Revenue Recognition [Line Items]
Total research and development revenue, related party	12,900
Millennium Pharmaceuticals Inc
Revenue Recognition [Line Items]
Total research and development revenue, related party	12,899	3,063	13,136	3,396
Millennium Pharmaceuticals Inc | Takeda Development Agreement
Revenue Recognition [Line Items]
Total research and development revenue, related party	12,899	3,028	13,114	3,176
Millennium Pharmaceuticals Inc | Takeda Multi Target Agreement
Revenue Recognition [Line Items]
Total research and development revenue, related party	$ 0	$ 35	$ 22	$ 220