Segment Information, Operating Results by Segment (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenue [Abstract]
Revenue	$ 363,041	$ 338,475	$ 719,518	$ 679,872
Operating income (loss)	52,181	44,380	107,862	68,417
Interest expense	5,555	4,717	11,110	9,528
Earnings before income taxes	46,626	39,663	96,752	58,889
Flavors & Fragrances [Member]
Revenue [Abstract]
Revenue	191,818	180,736	374,300	361,811
Operating income (loss)	24,001	28,502	49,328	57,272
Interest expense	0	0	0	0
Earnings before income taxes	24,001	28,502	49,328	57,272
Color [Member]
Revenue [Abstract]
Revenue	140,702	129,253	284,430	260,093
Operating income (loss)	31,133	29,072	64,805	59,289
Interest expense	0	0	0	0
Earnings before income taxes	31,133	29,072	64,805	59,289
Asia Pacific [Member]
Revenue [Abstract]
Revenue	30,521	28,486	60,788	57,968
Operating income (loss)	4,634	3,820	9,506	8,970
Interest expense	0	0	0	0
Earnings before income taxes	4,634	3,820	9,506	8,970
Reportable Segments [Member]
Revenue [Abstract]
Revenue	373,470	347,395	739,243	697,972
Reportable Segments [Member] \| Flavors & Fragrances [Member]
Revenue [Abstract]
Revenue	198,658	185,556	387,004	372,431
Reportable Segments [Member] \| Color [Member]
Revenue [Abstract]
Revenue	144,291	132,894	291,451	266,960
Reportable Segments [Member] \| Asia Pacific [Member]
Revenue [Abstract]
Revenue	30,521	28,945	60,788	58,581
Intersegment Revenue [Member]
Revenue [Abstract]
Revenue	(10,429)	(8,920)	(19,725)	(18,100)
Intersegment Revenue [Member] \| Flavors & Fragrances [Member]
Revenue [Abstract]
Revenue	(6,840)	(4,820)	(12,704)	(10,620)
Intersegment Revenue [Member] \| Color [Member]
Revenue [Abstract]
Revenue	(3,589)	(3,641)	(7,021)	(6,867)
Intersegment Revenue [Member] \| Asia Pacific [Member]
Revenue [Abstract]
Revenue	0	(459)	0	(613)
Corporate & Other [Member]
Revenue [Abstract]
Revenue	0	0	0	0
Operating income (loss)	(7,587)	(17,014)	(15,777)	(57,114)
Interest expense	5,555	4,717	11,110	9,528
Earnings before income taxes	$ (13,142)	$ (21,731)	$ (26,887)	$ (66,642)

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