Industry Segments - Schedule of reporting information by segment (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Net Sales	$ 139,194	$ 141,661	$ 164,335	$ 156,348	$ 158,271	$ 162,109	$ 152,784	$ 150,485	$ 601,538	$ 623,649	$ 584,733
Income from Continuing Operations Before Income Taxes									30,861	22,618	44,316
Interest expense - net									(8,999)	(8,535)	(4,531)
Income from continuing operations before income taxes									21,862	14,083	39,785
Identifiable Assets	429,916				564,833				429,916	564,833	469,457
Capital Additions, Net									23,727	24,170	20,709
Depreciation and Amortization									34,979	31,172	23,528
Operating Segments | Material Handling
Segment Reporting Information [Line Items]
Net Sales									414,030	432,054	380,605
Income from Continuing Operations Before Income Taxes									49,762	31,903	47,428
Identifiable Assets	335,506				370,501				335,506	370,501	240,897
Capital Additions, Net									21,422	22,197	18,787
Depreciation and Amortization									32,667	29,013	21,728
Operating Segments | Distribution
Segment Reporting Information [Line Items]
Net Sales									187,637	191,873	204,460
Income from Continuing Operations Before Income Taxes									16,114	16,024	21,727
Identifiable Assets	58,772				57,523				58,772	57,523	63,340
Capital Additions, Net									1,795	1,786	915
Depreciation and Amortization									998	1,022	859
Operating Segments | Discontinued Operations [Member]
Segment Reporting Information [Line Items]
Identifiable Assets	0				117,775				0	117,775	160,568
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Net Sales									(129)	(278)	(332)
Corporate
Segment Reporting Information [Line Items]
Income from Continuing Operations Before Income Taxes									(35,015)	(25,309)	(24,839)
Identifiable Assets	$ 35,638				$ 19,034				35,638	19,034	4,652
Capital Additions, Net									510	187	1,007
Depreciation and Amortization									$ 1,314	$ 1,137	$ 941