Industry Segments - Schedule of reporting information by segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Segment Reporting Information [Line Items]
Net sales	$ 142,303	$ 144,117	$ 284,006	$ 295,322
Operating Income	5,580	11,166	12,938	12,295
Interest expense, net	(1,785)	(2,053)	(3,760)	(4,072)
Income from continuing operations before income taxes	3,795	9,113	9,178	8,223
Operating Segments [Member] | Material Handling [Member]
Segment Reporting Information [Line Items]
Net sales	103,074	100,907	206,254	209,931
Operating Income	7,426	14,333	19,514	21,774
Operating Segments [Member] | Distribution [Member]
Segment Reporting Information [Line Items]
Net sales	39,258	43,234	77,832	85,455
Operating Income	3,025	3,966	4,563	6,502
Inter-company sales [Member]
Segment Reporting Information [Line Items]
Net sales	(29)	(24)	(80)	(64)
Corporate [Member]
Segment Reporting Information [Line Items]
Operating Income	$ (4,871)	$ (7,133)	$ (11,139)	$ (15,981)