Segment Information, Operating Results by Segment (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue [Abstract]
Revenue	$ 317,650	$ 342,734	$ 1,004,349	$ 1,062,252
Operating income (loss)	38,788	50,264	135,576	158,126
Interest expense	4,936	5,407	15,538	16,517
Earnings before income taxes	33,852	44,857	120,038	141,609
Flavors & Fragrances [Member]
Revenue [Abstract]
Revenue	163,870	179,103	517,148	553,403
Operating income (loss)	17,600	24,814	60,775	74,142
Interest expense	0	0	0	0
Earnings before income taxes	17,600	24,814	60,775	74,142
Color [Member]
Revenue [Abstract]
Revenue	123,710	132,356	399,610	416,786
Operating income (loss)	23,436	26,565	81,512	91,370
Interest expense	0	0	0	0
Earnings before income taxes	23,436	26,565	81,512	91,370
Asia Pacific [Member]
Revenue [Abstract]
Revenue	30,070	31,275	87,591	92,063
Operating income (loss)	5,406	5,750	13,825	15,256
Interest expense	0	0	0	0
Earnings before income taxes	5,406	5,750	13,825	15,256
Reportable Segments [Member]
Revenue [Abstract]
Revenue	324,707	350,802	1,028,706	1,090,045
Reportable Segments [Member] \| Flavors & Fragrances [Member]
Revenue [Abstract]
Revenue	167,577	184,397	531,264	571,401
Reportable Segments [Member] \| Color [Member]
Revenue [Abstract]
Revenue	127,005	135,130	409,796	426,581
Reportable Segments [Member] \| Asia Pacific [Member]
Revenue [Abstract]
Revenue	30,125	31,275	87,646	92,063
Intersegment Revenue [Member]
Revenue [Abstract]
Revenue	(7,057)	(8,068)	(24,357)	(27,793)
Intersegment Revenue [Member] \| Flavors & Fragrances [Member]
Revenue [Abstract]
Revenue	(3,707)	(5,294)	(14,116)	(17,998)
Intersegment Revenue [Member] \| Color [Member]
Revenue [Abstract]
Revenue	(3,295)	(2,774)	(10,186)	(9,795)
Intersegment Revenue [Member] \| Asia Pacific [Member]
Revenue [Abstract]
Revenue	(55)	0	(55)	0
Corporate & Other [Member]
Revenue [Abstract]
Revenue	0	0	0	0
Operating income (loss)	(7,654)	(6,865)	(20,536)	(22,642)
Interest expense	4,936	5,407	15,538	16,517
Earnings before income taxes	$ (12,590)	$ (12,272)	$ (36,074)	$ (39,159)

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