Significant agreements - Deferred revenue (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Deferred revenue
Contract assets	$ 0	$ 0
Deferred revenue	65,578	71,340	$ 35,156
Deferred revenue material rights option
Deferred revenue
Deferred revenue	3,900
Ionis
Deferred revenue
Deferred revenue	30,895	34,115
Genentech
Deferred revenue
Deferred revenue	32,042	34,436	27,579
Genentech | Deferred revenue material rights option
Deferred revenue
Deferred revenue	24,300
AstraZeneca
Deferred revenue
Deferred revenue	2,295	$ 2,361	$ 3,756
AstraZeneca | Target 4 and Target 5 Material Rights
Deferred revenue
Deferred revenue	$ 2,400