Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Sales of goods	$ 91,811	$ 97,629
Sales of services	30,643	21,073
Total net sales	122,454	118,702
Cost of goods sold	75,300	79,401
Cost of services sold	25,126	18,049
Total cost of sales	100,426	97,450
Gross profit	22,028	21,252
Selling and administrative expenses	20,458	19,227
Amortization expense	1,785	1,759
Interest expense	1,958	2,108
Interest income	(71)	(56)
Equity in loss of nonconsolidated investments	3	200
Other (income) expense	(608)	5
Total operating expenses	23,525	23,243
Loss before income taxes	(1,497)	(1,991)
Income tax expense	525	431
Net loss	$ (2,022)	$ (2,422)
Basic loss per common share (usd per share)	$ (0.20)	$ (0.23)
Diluted loss per common share (usd per share)	(0.20)	(0.23)
Dividends paid per common share (usd per share)	$ 0	$ 0