Industry Segments - Schedule of reporting information by segment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Net sales	$ 144,075	$ 132,676	$ 428,081	$ 427,998
Operating Income	7,111	2,986	20,049	15,281
Interest expense, net	(1,785)	(2,015)	(5,545)	(6,087)
Income from continuing operations before income taxes	5,326	971	14,504	9,194
Operating Segments [Member] | Material Handling [Member]
Segment Reporting Information [Line Items]
Net sales	104,089	89,911	310,343	299,842
Operating Income	10,325	4,378	29,839	26,152
Operating Segments [Member] | Distribution [Member]
Segment Reporting Information [Line Items]
Net sales	40,004	42,793	117,836	128,248
Operating Income	3,179	3,301	7,742	9,803
Inter-company sales [Member]
Segment Reporting Information [Line Items]
Net sales	(18)	(28)	(98)	(92)
Corporate [Member]
Segment Reporting Information [Line Items]
Operating Income	$ (6,393)	$ (4,693)	$ (17,532)	$ (20,674)