Collaborations, contracts and licensing agreements - Revenue from collaborations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenues	$ 179,126	$ 1,764
Revenue from collaborations and licenses
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenues	178,741	0
Revenue from collaborations and licenses | Acuitas Therapeutics, Inc.
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenues	204	504
Revenue from collaborations and licenses | Qilu Pharmaceutical Co, LTD.
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenues	0	812
Revenue from collaborations and licenses | Genevant
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenues	178,741	0
Non-cash royalty revenue
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenues	181	448
Non-cash royalty revenue | Alnylam Pharmaceuticals, Inc.
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Revenues	$ 181	$ 448