Segment Information, Revenue from External Customers by Product Line (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenue [Abstract]
Revenue	$ 350,677	$ 347,513
Flavors, Extracts & Flavor Ingredients [Member]
Revenue [Abstract]
Revenue	101,453	103,528
Natural Ingredients [Member]
Revenue [Abstract]
Revenue	57,600	51,219
Fragrances [Member]
Revenue [Abstract]
Revenue	22,284	23,267
Yogurt Fruit Preparations [Member]
Revenue [Abstract]
Revenue	5,161	5,539
Food & Beverage Colors [Member]
Revenue [Abstract]
Revenue	90,793	88,848
Personal Care [Member]
Revenue [Abstract]
Revenue	43,743	44,921
Inks [Member]
Revenue [Abstract]
Revenue	8,959	10,110
Asia Pacific [Member]
Revenue [Abstract]
Revenue	30,449	28,519
Flavors & Fragrances [Member]
Revenue [Abstract]
Revenue	181,187	178,744
Flavors & Fragrances [Member] | Flavors, Extracts & Flavor Ingredients [Member]
Revenue [Abstract]
Revenue	101,453	103,528
Flavors & Fragrances [Member] | Natural Ingredients [Member]
Revenue [Abstract]
Revenue	57,600	51,219
Flavors & Fragrances [Member] | Fragrances [Member]
Revenue [Abstract]
Revenue	22,284	23,267
Flavors & Fragrances [Member] | Yogurt Fruit Preparations [Member]
Revenue [Abstract]
Revenue	5,161	5,539
Color [Member]
Revenue [Abstract]
Revenue	139,193	140,250
Color [Member] | Food & Beverage Colors [Member]
Revenue [Abstract]
Revenue	90,793	88,848
Color [Member] | Personal Care [Member]
Revenue [Abstract]
Revenue	43,743	44,921
Color [Member] | Inks [Member]
Revenue [Abstract]
Revenue	8,959	10,110
Asia Pacific [Member]
Revenue [Abstract]
Revenue	30,297	28,519
Asia Pacific [Member] | Asia Pacific [Member]
Revenue [Abstract]
Revenue	30,449	28,519
Intersegment Revenue [Member]
Revenue [Abstract]
Revenue	9,765	8,438
Intersegment Revenue [Member] | Flavors & Fragrances [Member]
Revenue [Abstract]
Revenue	5,311	4,809
Intersegment Revenue [Member] | Color [Member]
Revenue [Abstract]
Revenue	4,302	3,629
Intersegment Revenue [Member] | Asia Pacific [Member]
Revenue [Abstract]
Revenue	$ 152	$ 0