Reconciliation of income and expenses (Details 3) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income (loss) from discontinued operations	$ (163)	$ 477
Discontinued operations, held-for-sale or disposed of by sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Operating revenues	30	66
Operating expenses	245	174
Operating loss	(215)	(108)
Other income	0	12
Interest expense	0	575
Loss from discontinued operations before income taxes	(215)	(671)
Income taxes	(52)	(1,148)
Income (loss) from discontinued operations	$ (163)	$ 477