Industry Segments - Schedule of reporting information by segment (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Net sales	$ 130,064	$ 132,676	$ 144,117	$ 151,205	$ 139,194	$ 141,661	$ 164,335	$ 156,348	$ 558,062	$ 601,538	$ 623,649
Operating Income									16,168	30,861	22,618
Interest expense, net									(8,173)	(8,999)	(8,535)
Income from continuing operations before income taxes									7,995	21,862	14,083
Identifiable Assets	381,684				428,791				381,684	428,791	563,433
Capital Additions, Net									12,523	23,727	24,170
Depreciation and Amortization									34,465	34,979	31,172
Operating Segments [Member] | Material Handling [Member]
Segment Reporting Information [Line Items]
Net sales									387,513	414,030	432,054
Operating Income									29,583	49,762	31,903
Identifiable Assets	289,341				335,506				289,341	335,506	370,501
Capital Additions, Net									10,967	21,422	22,197
Depreciation and Amortization									31,943	32,667	29,013
Operating Segments [Member] | Distribution [Member]
Segment Reporting Information [Line Items]
Net sales									170,660	187,637	191,873
Operating Income									12,834	16,114	16,024
Identifiable Assets	56,072				58,772				56,072	58,772	57,523
Capital Additions, Net									1,424	1,795	1,786
Depreciation and Amortization									1,221	998	1,022
Operating Segments [Member] | Discontinued Operations [Member]
Segment Reporting Information [Line Items]
Identifiable Assets	0				0				0	0	117,775
Inter-company sales [Member]
Segment Reporting Information [Line Items]
Net sales									(111)	(129)	(278)
Corporate [Member]
Segment Reporting Information [Line Items]
Operating Income									(26,249)	(35,015)	(25,309)
Identifiable Assets	$ 36,271				$ 34,513				36,271	34,513	17,634
Capital Additions, Net									132	510	187
Depreciation and Amortization									$ 1,301	$ 1,314	$ 1,137