Stock compensation and other employee benefit plans - Stock compensation expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock compensation expense	$ 8,295	$ 20,303	$ 61,765
Cost of Revenue [Member]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock compensation expense	1,596	3,292	8,094
Research and Development [Member]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock compensation expense	541	1,460	3,657
Selling and Marketing [Member]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock compensation expense	718	1,889	2,056
General and Administrative [Member]
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock compensation expense	$ 5,440	$ 13,662	$ 47,958