Income taxes - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Taxes [Line Items]
Loss carryforwards	$ 16,435	$ 12,537
Deferred tax assets valuation allowance	25,001	26,339	$ 41,929	$ 43,467
Decrease in valuation allowance	1,300
Unrecognized tax benefits that, if recognized, would impact effective tax rate	5,600	6,400
Recognized expense/income from the release of penalty reserves	300	200	$ 700
Accrued interest expense and penalties payable related to unrecognized tax benefits	700	$ 900
Estimated decrease in gross unrecognized tax positions within the next 12 months, maximum	2,600
State
Income Taxes [Line Items]
Tax credit carryforward	7,200
Loss carryforwards	11,300
Federal
Income Taxes [Line Items]
Loss carryforwards	$ 3,700