Segment Reporting (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2017 USD ($) segment	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)
Segment Reporting Information [Line Items]
Number of principal reporting segments | segment									3
Net Revenue	$ 243,260	$ 240,455	$ 213,276	$ 215,389	$ 205,522	$ 216,766	$ 211,489	$ 210,971	$ 912,380	$ 844,748	$ 879,577
Income from Operations									88,738	67,620	66,528
Goodwill	84,761				74,825				84,761	74,825	75,509	$ 75,691
Total Identifiable Assets	639,671				552,776				639,671	552,776
Industrial
Segment Reporting Information [Line Items]
Net Revenue									522,706	484,088	498,761
Income from Operations									51,914	35,984	42,194
Goodwill	61,682				56,447				61,682	56,447	56,293	57,320
Total Identifiable Assets	369,271				339,064				369,271	339,064
Agricultural
Segment Reporting Information [Line Items]
Net Revenue									227,389	205,834	208,257
Income from Operations									24,059	20,720	17,295
Goodwill	6,357				3,489				6,357	3,489	2,984	695
Total Identifiable Assets	141,023				111,120				141,023	111,120
European
Segment Reporting Information [Line Items]
Net Revenue									162,285	154,826	172,559
Income from Operations									12,765	10,916	7,039
Goodwill	16,722				14,889				16,722	14,889	$ 16,232	$ 17,676
Total Identifiable Assets	$ 129,377				$ 102,592				$ 129,377	$ 102,592