Earnings per share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Earnings Per Share [Abstract]
Weighted average common shares outstanding during the period - shares used for basic earnings per common share	9,843	10,062	9,903	10,037
Common shares issuable under share based payment plans which are potentially dilutive	43	73	42	73
Common shares used for diluted earnings per common share	9,886	10,135	9,945	10,110
Income from continuing operations	$ 1,902	$ 2,030	$ 6,495	$ 458
Discontinued operations	(13)	(78)	6,849	122,109
Net income attributable to the Company	$ 2,001	$ 2,224	$ 13,724	$ 123,766
Basic earnings per common share:
Income from continuing operations	$ 0.19	$ 0.20	$ 0.66	$ 0.05
Discontinued operations	0.00	(0.01)	0.69	12.17
Net income attributable to the Company	0.20	0.22	1.39	12.33
Diluted earnings per common share
Income from continuing operations	0.19	0.20	0.65	0.05
Discontinued operations	0.00	(0.01)	0.69	12.08
Net income attributable to the Company	$ 0.20	$ 0.22	$ 1.38	$ 12.24