Major classes of assets and liabilities held for sale (Details 2) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018	Sep. 30, 2018
Current assets:
Total current assets held for sale	$ 426	$ 430	$ 571
Noncurrent assets:
Total noncurrent assets held for sale	2,087	2,087	1,835
Current liabilities:
Total current liabilities held for sale	3,393	4,001	7,959
Discontinued operations, held-for-sale or disposed of by sale
Current assets:
Receivables, net	426	430	571
Income taxes receivable (a)	0	0	1,640
Total current assets held for sale	426	430	2,211
Noncurrent assets:
Deferred income taxes	1,926	1,926	1,711
Other	161	161	161
Total noncurrent assets held for sale	2,087	2,087	1,872
Total assets held for sale	2,513	2,517	4,083
Current liabilities:
Accounts payable	0	80	188
Taxes payable	1,300	1,451	7,463
Other accrued liabilities	2,093	2,470	1,948
Total current liabilities held for sale	3,393	4,001	9,599
Noncurrent liabilities:
Deferred income taxes (b)	0	0	37
Total noncurrent liabilities held for sale	0	0	37
Total liabilities held for sale	$ 3,393	$ 4,001	$ 9,636