Segment Information, Revenue from External Customers by Geographic Markets (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue [Abstract]
Revenue	$ 342,734	$ 353,519	$ 1,062,252	$ 1,033,391
North America [Member]
Revenue [Abstract]
Revenue	182,635	191,211	556,206	556,097
Europe [Member]
Revenue [Abstract]
Revenue	77,875	79,755	253,054	238,911
Asia Pacific [Member]
Revenue [Abstract]
Revenue	53,995	52,336	164,932	152,551
Other [Member]
Revenue [Abstract]
Revenue	28,229	30,217	88,060	85,832
Flavors & Fragrances [Member]
Revenue [Abstract]
Revenue	179,103	191,063	553,403	552,874
Color [Member]
Revenue [Abstract]
Revenue	132,187	129,899	416,617	389,992
Asia Pacific [Member]
Revenue [Abstract]
Revenue	31,275	32,557	92,063	90,525
Asia Pacific [Member] | Asia Pacific [Member]
Revenue [Abstract]
Revenue	31,275	32,557	92,063	90,525
Reportable Geographical Components [Member] | Flavors & Fragrances [Member] | North America [Member]
Revenue [Abstract]
Revenue	118,690	131,632	364,941	375,481
Reportable Geographical Components [Member] | Flavors & Fragrances [Member] | Europe [Member]
Revenue [Abstract]
Revenue	42,866	40,891	133,257	125,812
Reportable Geographical Components [Member] | Flavors & Fragrances [Member] | Asia Pacific [Member]
Revenue [Abstract]
Revenue	7,053	7,042	23,144	20,164
Reportable Geographical Components [Member] | Flavors & Fragrances [Member] | Other [Member]
Revenue [Abstract]
Revenue	10,494	11,498	32,061	31,417
Reportable Geographical Components [Member] | Color [Member] | North America [Member]
Revenue [Abstract]
Revenue	63,850	59,579	191,170	180,616
Reportable Geographical Components [Member] | Color [Member] | Europe [Member]
Revenue [Abstract]
Revenue	34,854	38,686	119,612	112,796
Reportable Geographical Components [Member] | Color [Member] | Asia Pacific [Member]
Revenue [Abstract]
Revenue	15,910	13,357	50,461	43,158
Reportable Geographical Components [Member] | Color [Member] | Other [Member]
Revenue [Abstract]
Revenue	17,573	18,277	55,374	53,422
Reportable Geographical Components [Member] | Asia Pacific [Member] | North America [Member]
Revenue [Abstract]
Revenue	0	0	0	0
Reportable Geographical Components [Member] | Asia Pacific [Member] | Europe [Member]
Revenue [Abstract]
Revenue	81	178	111	303
Reportable Geographical Components [Member] | Asia Pacific [Member] | Asia Pacific [Member]
Revenue [Abstract]
Revenue	31,032	31,937	91,327	89,229
Reportable Geographical Components [Member] | Asia Pacific [Member] | Other [Member]
Revenue [Abstract]
Revenue	162	442	625	993
Corporate & Other [Member]
Revenue [Abstract]
Revenue	169	0	169	0
Corporate & Other [Member] | North America [Member]
Revenue [Abstract]
Revenue	95	0	95	0
Corporate & Other [Member] | Europe [Member]
Revenue [Abstract]
Revenue	74	0	74	0
Corporate & Other [Member] | Asia Pacific [Member]
Revenue [Abstract]
Revenue	0	0	0	0
Corporate & Other [Member] | Other [Member]
Revenue [Abstract]
Revenue	$ 0	$ 0	$ 0	$ 0