SEGMENT INFORMATION - Capital Expenditures (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Capital expenditures	$ 27,526	$ 23,034	$ 41,300
Human Nutrition & Health [Member] | Reportable Segments [Member]
Segment Reporting Information [Line Items]
Capital expenditures	20,580	14,470	21,361
Animal Nutrition & Health [Member] | Reportable Segments [Member]
Segment Reporting Information [Line Items]
Capital expenditures	4,424	6,577	17,854
Specialty Products [Member] | Reportable Segments [Member]
Segment Reporting Information [Line Items]
Capital expenditures	1,306	1,286	940
Industrial Products [Member] | Reportable Segments [Member]
Segment Reporting Information [Line Items]
Capital expenditures	$ 1,216	$ 701	$ 1,145