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Restructuring and Other Charges, Net - Changes in Employee-Related Restructuring Liabilities (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Restructuring Reserve [Roll Forward]
Beginning Balance			$ 5,200
Additional Charges (Reversals), Net			22,415
Non-Cash Charges			(1,182)
Additional charges, net	$ 3,716	$ 927	22,415	$ 2,830
Payments			(10,457)
Ending Balance	15,976		15,976
Frutarom Integration Initiative \| Employee Severance
Restructuring Reserve [Roll Forward]
Beginning Balance			0
Additional Charges (Reversals), Net			3,772
Non-Cash Charges			0
Additional charges, net			7,600
Payments			(2,285)
Ending Balance	1,487		1,487
Frutarom Integration Initiative \| Fixed Asset Write Down [Member]
Restructuring Reserve [Roll Forward]
Beginning Balance			0
Additional Charges (Reversals), Net			1,182
Non-Cash Charges			(1,182)
Payments			0
Ending Balance	0		0
Frutarom Integration Initiative \| Other
Restructuring Reserve [Roll Forward]
Beginning Balance			0
Additional Charges (Reversals), Net			2,666
Non-Cash Charges			0
Payments			(1,088)
Ending Balance	1,578		1,578
2019 Severance Initiatives \| Employee Severance
Restructuring Reserve [Roll Forward]
Beginning Balance			0
Additional Charges (Reversals), Net			14,430
Non-Cash Charges			0
Additional charges, net			14,800
Payments			(5,924)
Ending Balance	8,506		8,506
2019 Severance Initiatives \| Other
Restructuring Reserve [Roll Forward]
Beginning Balance			0
Additional Charges (Reversals), Net			365
Non-Cash Charges			0
Payments			(365)
Ending Balance	0		0
2017 Productivity Program
Restructuring Reserve [Roll Forward]
Additional charges, net			24,500
2017 Productivity Program \| Employee Severance
Restructuring Reserve [Roll Forward]
Beginning Balance			4,125
Additional Charges (Reversals), Net			0
Non-Cash Charges			0
Payments			(795)
Ending Balance	3,330		3,330
2017 Productivity Program \| Other
Restructuring Reserve [Roll Forward]
Beginning Balance			1,075
Additional Charges (Reversals), Net			0
Non-Cash Charges			0
Payments			0
Ending Balance	1,075		1,075
Taste [Member]
Restructuring Reserve [Roll Forward]
Additional charges, net	88	0	328	1,646
Scent [Member]
Restructuring Reserve [Roll Forward]
Additional charges, net	803	927	11,703	1,184
Frutarom
Restructuring Reserve [Roll Forward]
Additional charges, net	2,453	0	7,290	0
Shared IT & Corporate Costs [Member]
Restructuring Reserve [Roll Forward]
Additional charges, net	$ 372	$ 0	$ 3,094	$ 0