Earnings per share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Weighted average common shares outstanding during the period - shares used for basic earnings per common share	9,620	9,915	9,712	9,933
Common shares issuable under share based payment plans which are potentially dilutive	29	45	32	45
Common shares used for diluted earnings per common share	9,649	9,960	9,744	9,978
Income from continuing operations	$ 3,977	$ 2,952	$ 5,476	$ 4,593
Discontinued operations	0	6,776	0	6,862
Net income attributable to the Company	$ 4,149	$ 9,825	$ 5,767	$ 11,723
Basic earnings per common share:
Income from continuing operations	$ 0.41	$ 0.30	$ 0.56	$ 0.46
Discontinued operations	0.00	0.68	0.00	0.69
Net income attributable to the Company	0.43	0.99	0.59	1.18
Diluted earnings per common share
Income from continuing operations	0.41	0.30	0.56	0.46
Discontinued operations	0.00	0.68	0.00	0.69
Net income attributable to the Company	$ 0.43	$ 0.99	$ 0.59	$ 1.17