Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Sales of goods	$ 103,058	$ 100,293	$ 318,414	$ 326,278
Sales of services	28,434	14,351	76,640	50,670
Total net sales	131,492	114,644	395,054	376,948
Cost of goods sold	82,460	81,674	256,152	260,705
Cost of services sold	22,667	13,167	63,549	44,667
Total cost of sales	105,127	94,841	319,701	305,372
Gross profit	26,365	19,803	75,353	71,576
Selling and administrative expenses	20,218	19,807	60,023	65,941
Amortization expense	1,764	1,763	5,218	7,818
Asset impairments	0	6,946	0	135,884
Interest expense	2,026	1,520	6,315	4,342
Interest income	(56)	(50)	(166)	(157)
Equity in (income) loss of nonconsolidated investments	(50)	263	5	946
Other income	(551)	(1,085)	(564)	(263)
Total operating expenses	23,351	29,164	70,831	214,511
Income (loss) before income taxes	3,014	(9,361)	4,522	(142,935)
Income tax (benefit) expense	(208)	(3,379)	698	(42,125)
Net income (loss)	$ 3,222	$ (5,982)	$ 3,824	$ (100,810)
Basic earnings (loss) per common share (usd per share)	$ 0.31	$ (0.58)	$ 0.37	$ (9.82)
Diluted earnings (loss) per common share (usd per share)	0.31	(0.58)	0.37	(9.82)
Dividends paid per common share (usd per share)	$ 0	$ 0.04	$ 0	$ 0.12