Segment Information, Revenue from External Customers by Product Line (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenue [Abstract]
Revenue	$ 356,477	$ 341,397
Flavors & Fragrances [Member]
Revenue [Abstract]
Revenue	182,482	181,075
Flavors [Member]
Revenue [Abstract]
Revenue	109,051	113,617
Natural Ingredients [Member]
Revenue [Abstract]
Revenue	53,201	53,522
Fragrances [Member]
Revenue [Abstract]
Revenue	26,094	19,736
Color [Member]
Revenue [Abstract]
Revenue	143,728	130,840
Food & Beverage Colors [Member]
Revenue [Abstract]
Revenue	76,816	71,388
Cosmetics [Member]
Revenue [Abstract]
Revenue	45,504	37,459
Other Colors [Member]
Revenue [Abstract]
Revenue	24,840	25,219
Asia Pacific [Member]
Revenue [Abstract]
Revenue	30,267	29,482
Intersegment Revenue [Member]
Revenue [Abstract]
Revenue	(9,296)	(9,180)
Intersegment Revenue [Member] | Flavors & Fragrances [Member]
Revenue [Abstract]
Revenue	(5,864)	(5,800)
Intersegment Revenue [Member] | Color [Member]
Revenue [Abstract]
Revenue	(3,432)	(3,226)
Intersegment Revenue [Member] | Asia Pacific [Member]
Revenue [Abstract]
Revenue	$ 0	$ (154)