Segment Information, Revenue from External Customers by Product Line (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenue [Abstract]
Revenue	$ 347,513	$ 356,477
Flavors & Fragrances [Member]
Revenue [Abstract]
Revenue	178,744	182,482
Flavors [Member]
Revenue [Abstract]
Revenue	104,276	109,051
Natural Ingredients [Member]
Revenue [Abstract]
Revenue	51,219	53,201
Fragrances [Member]
Revenue [Abstract]
Revenue	28,058	26,094
Color [Member]
Revenue [Abstract]
Revenue	140,250	143,728
Food & Beverage Colors [Member]
Revenue [Abstract]
Revenue	80,364	76,816
Cosmetics [Member]
Revenue [Abstract]
Revenue	38,283	45,504
Other Colors [Member]
Revenue [Abstract]
Revenue	25,232	24,840
Asia Pacific [Member]
Revenue [Abstract]
Revenue	28,519	30,267
Intersegment Revenue [Member]
Revenue [Abstract]
Revenue	(8,438)	(9,296)
Intersegment Revenue [Member] | Flavors & Fragrances [Member]
Revenue [Abstract]
Revenue	(4,809)	(5,864)
Intersegment Revenue [Member] | Color [Member]
Revenue [Abstract]
Revenue	(3,629)	(3,432)
Intersegment Revenue [Member] | Asia Pacific [Member]
Revenue [Abstract]
Revenue	$ 0	$ 0