CONSOLIDATED STATEMENT OF INCOME AND COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Net sales	$ 1,268,076	$ 1,267,345	$ 3,814,166	$ 3,856,315
Cost of goods sold	743,649	734,257	2,242,030	2,245,729
Gross profit	524,427	533,088	1,572,136	1,610,586
Research and development expenses	89,968	85,077	256,825	260,489
Selling and administrative expenses	234,520	210,829	694,641	634,111
Amortization of acquisition-related intangibles	47,738	48,430	144,922	143,964
Restructuring and other charges, net	1,497	3,716	8,299	22,415
Losses on sales of fixed assets	415	372	1,568	1,136
Operating profit	150,289	184,664	465,881	548,471
Interest expense	34,844	33,497	99,046	102,662
Other expense (income), net	9,945	(5,699)	4,762	(15,114)
Income before taxes	105,500	156,866	362,073	460,923
Taxes on income	19,269	27,059	61,265	81,033
Net income	86,231	129,807	300,808	379,890
Net income attributable to noncontrolling interests	1,403	2,683	5,169	7,560
Net income attributable to IFF stockholders	84,828	127,124	295,639	372,330
Other comprehensive income (loss), net, after tax:
Foreign currency translation adjustments	79,291	(204,853)	(226,519)	(176,490)
(Losses) gains on derivatives qualifying as hedges	(4,751)	2,939	(6,405)	3,257
Pension and postretirement net liability	3,507	2,721	10,399	7,908
Net current period other comprehensive income (loss)	78,047	(199,193)	(222,525)	(165,325)
Comprehensive income (loss) attributable to IFF stockholders	$ 162,875	$ (72,069)	$ 73,114	$ 207,005
Net income per share - basic (in dollars per share)	$ 0.76	$ 1.15	$ 2.68	$ 3.34
Net income per share - diluted (in dollars per share)	$ 0.75	$ 1.13	$ 2.64	$ 3.30
Average number of shares outstanding - basic (in shares)	112,183	111,998	112,148	111,953
Average number of shares outstanding - diluted (in shares)	113,622	113,493	113,631	113,133