Basic and diluted earnings per common share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Earnings per common share:
Weighted average common shares outstanding during the period – shares used for basic  earnings per common share	9,366	9,341
Common shares issuable under share based  payment plans which are potentially dilutive	51	35
Common shares used for diluted  earnings per common share	9,417	9,376
Net income attributable to the Company	$ 672	$ 28,373
-basic	$ 0.07	$ 3.04
-diluted	$ 0.07	$ 3.03