Stock-based compensation - Summary of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation	$ 3,277	$ 2,518
Cost of goods sold
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation	548	537
Research and development
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation	862	758
Sales and marketing
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation	554	530
General and administrative
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Share-based compensation	$ 1,313	$ 693