SEGMENT INFORMATION, Business Segment Net Sales (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Segment information [Abstract]
Net sales	$ 155,043	$ 150,716	$ 480,140	$ 435,526
Human Nutrition & Health [Member] | Reportable Segments [Member]
Segment information [Abstract]
Net sales	85,890	81,365	253,966	232,523
Animal Nutrition & Health [Member] | Reportable Segments [Member]
Segment information [Abstract]
Net sales	40,410	38,010	128,587	113,136
Specialty Products [Member] | Reportable Segments [Member]
Segment information [Abstract]
Net sales	17,629	17,264	58,233	56,813
Industrial Products [Member] | Reportable Segments [Member]
Segment information [Abstract]
Net sales	$ 11,114	$ 14,077	$ 39,354	$ 33,054