Earnings per share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Weighted average common shares outstanding during the period - shares used for basic earnings per common share	9,517	9,843	9,646	9,903
Common shares issuable under share based payment plans which are potentially dilutive	28	43	35	42
Common shares used for diluted earnings per common share	9,545	9,886	9,681	9,945
Income from continuing operations	$ 5,271	$ 1,902	$ 10,747	$ 6,495
Discontinued operations	0	(13)	0	6,849
Net income attributable to the Company	$ 5,455	$ 2,001	$ 11,222	$ 13,724
Basic earnings per common share:
Income from continuing operations	$ 0.55	$ 0.19	$ 1.11	$ 0.66
Discontinued operations	0.00	0.00	0.00	0.69
Net income attributable to the Company	0.57	0.20	1.16	1.39
Diluted earnings per common share
Income from continuing operations	0.55	0.19	1.11	0.65
Discontinued operations	0.00	0.00	0.00	0.69
Net income attributable to the Company	$ 0.57	$ 0.20	$ 1.16	$ 1.38