Income taxes, Valuation allowance on deferred tax assets (Details) - Foreign Net Operating Loss Carryforwards [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Valuation allowance [Roll Forward]
Balance, beginning of period	$ 659	$ 444
Additions charged to income tax provision	74	215
Balance, end of period	$ 733	$ 659