Revenue and Segment Information - Revenue, Income, Goodwill and Identifiable Assets by Location (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Segment Reporting Information [Line Items]
Net Sales	$ 261,934	$ 238,087
Income from Operations	22,606	21,361
Goodwill	88,821		$ 83,243
Total Identifiable Assets	852,253		721,633
Industrial
Segment Reporting Information [Line Items]
Net Sales	158,425	132,167
Income from Operations	16,472	11,800
Goodwill	61,277		61,107
Total Identifiable Assets	451,549		421,539
Agricultural
Segment Reporting Information [Line Items]
Net Sales	53,173	58,647
Income from Operations	2,172	5,253
Goodwill	6,177		6,230
Total Identifiable Assets	184,495		162,548
European
Segment Reporting Information [Line Items]
Net Sales	50,336	47,273
Income from Operations	3,962	$ 4,308
Goodwill	21,367		15,906
Total Identifiable Assets	$ 216,209		$ 137,546