Income taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Deferred tax assets related to:
Net operating loss carryforwards	$ 35,505	$ 29,102
Stock-based compensation	3,008	3,207
Accruals and reserves	3,590	3,724
Inventory	1,408	425
Fixed assets	585	0
Lease liabilities	3,950	3,653
Tax credit carryforward	2,226	1,423
Capitalized research and development	4,818	2,405
Other	875	445
Total deferred tax assets	55,965	44,384
Deferred tax liabilities related to:
Intangibles	(3,696)	(6,150)
Right-of-use assets	(2,500)	(3,458)
Fair value change in investments	(440)	(447)
Fixed assets	0	(1,177)
Total deferred tax liabilities	(6,636)	(11,232)
Net deferred tax (liabilities) assets before valuation allowance	49,329	33,152
Less: valuation allowance	(49,517)	(33,402)	$ (2,993)	$ (8,498)
Net deferred tax liabilities	$ (188)	$ (250)