Income Taxes - Operating losses and credit carryforwards (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
US Federal loss carryforwards
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	$ 52,544	$ 55,029
Tax credit carryforward, amount	7,144	1,818
US state loss carryforwards
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	85,635	79,907
Foreign Tax Authority
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards	90,826	73,922
Tax credit carryforward, amount	$ 46,851	$ 46,851