Income taxes - Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Deferred tax assets:
Net operating loss carryforwards	$ 109,059	$ 118,399
Tax credit carryforwards	96,610	91,147
Stock-based compensation	5,966	6,034
Allowance for returns	1,823	1,818
Intangible assets	2,727	3,753
Deferred Tax Assets, Operating lease liabilities	8,326	10,177
Deferred Tax Assets, Property, Plant and Equipment	988	1,661
Accruals and reserves	20,540	22,001
Total deferred tax assets	301,305	284,112
Deferred Tax Liabilities Operating Lease Liability	(4,321)	(5,072)
Deferred Tax Liabilities, Gross, Total	4,321	$ 5,072
Deferred Tax Assets, Net, Total	$ 296,984		$ 279,040