Segment Information - Reportable Segment Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Net sales:
Net sales	$ 920,016	$ 842,861	$ 1,850,944	$ 1,671,154
Segment profit:
Restructuring and other charges, net	(1,186)	(791)	(1,903)	(10,934)
Gain on sales of fixed assets	(1,264)	68	(1,195)	89
Operating profit	154,509	151,687	329,363	281,750
Interest expense	(53,246)	(17,556)	(69,841)	(30,363)
Other income, net	20,655	7,909	21,232	29,140
Income before taxes	121,918	142,040	280,754	280,527
Flavor Compounds
Net sales:
Net sales	450,540	414,323	899,559	820,487
Segment profit:
Operating profit	109,605	96,840	221,169	191,395
Fragrances [Member]
Net sales:
Net sales	469,476	428,538	951,385	850,667
Segment profit:
Operating profit	80,780	80,993	174,056	158,867
Global expenses [Member]
Segment profit:
Operating profit	(20,572)	(13,488)	(44,398)	(29,781)
Corporate and Other [Member]
Segment profit:
Restructuring and other charges, net	(403)	(445)	(1,429)	(1,066)
Operational improvement initiative costs	(993)	(731)	(993)	(1,923)
Legal Charges/Credits, net	0	(1,000)	0	(1,000)
Gain on sales of fixed assets	0	19	0	(5,331)
Tax assessment	(193)	(791)	(910)	(10,934)
Integration-related costs	(1,264)	68	(1,195)	89
FDA mandated product recall	0	(3,500)	(5,000)	(3,500)
Acquisition Related Costs | Corporate and Other [Member]
Segment profit:
Acquisition and related costs	4	(6,278)	518	(15,066)
Frutarom Acquisition Related Costs | Corporate and Other [Member]
Segment profit:
Acquisition and related costs	$ (12,455)	$ 0	$ (12,455)	$ 0