Industry Segments - Schedule of reporting information by segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Segment Reporting Information [Line Items]
Net sales	$ 225,486	$ 174,429
Total operating income	24,405	10,865
Interest expense, net	(1,147)	(995)
Income before income taxes	23,258	9,870
Operating Segments [Member] | Material Handling [Member]
Segment Reporting Information [Line Items]
Net sales	176,636	129,893
Total operating income	31,220	16,927
Operating Segments [Member] | Distribution [Member]
Segment Reporting Information [Line Items]
Net sales	48,861	44,550
Total operating income	3,301	1,438
Inter-company sales [Member]
Segment Reporting Information [Line Items]
Net sales	(11)	(14)
Corporate [Member]
Segment Reporting Information [Line Items]
Total operating income	$ (10,116)	$ (7,500)