Industry Segments - Schedule of reporting information by segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Net sales	$ 144,117	$ 164,335	$ 295,322	$ 320,683
Operating Income	11,166	19,742	12,295	26,458
Interest expense, net	(2,053)	(2,467)	(4,072)	(5,169)
Income from continuing operations before income taxes	9,113	17,275	8,223	21,289
Operating Segments | Material Handling
Segment Reporting Information [Line Items]
Net sales	100,907	115,774	209,931	228,055
Operating Income	14,333	20,846	21,774	34,253
Operating Segments | Distribution
Segment Reporting Information [Line Items]
Net sales	43,234	48,592	85,455	92,697
Operating Income	3,966	4,508	6,502	7,999
Inter-company sales
Segment Reporting Information [Line Items]
Net sales	(24)	(31)	(64)	(69)
Corporate
Segment Reporting Information [Line Items]
Operating Income	$ (7,133)	$ (5,612)	$ (15,981)	$ (15,794)