CONSOLIDATED STATEMENT OF INCOME AND COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Net sales	$ 1,291,568	$ 920,016	$ 2,588,970	$ 1,850,944
Cost of goods sold	745,329	521,299	1,511,472	1,046,419
Gross profit	546,239	398,717	1,077,498	804,525
Research and development expenses	84,816	74,767	175,412	153,244
Selling and administrative expenses	210,100	157,407	423,282	300,051
Amortization of acquisition-related intangibles	47,909	9,584	95,534	18,769
Restructuring and other charges, net	2,525	1,186	18,699	1,903
Losses on sales of fixed assets	952	1,264	764	1,195
Operating profit	199,937	154,509	363,807	329,363
Interest expense	32,593	53,246	69,165	69,841
Other income, net	(2,137)	(20,655)	(9,415)	(21,232)
Income before taxes	169,481	121,918	304,057	280,754
Taxes on income	30,612	22,769	53,974	52,190
Net income	138,869	99,149	250,083	228,564
Net income attributable to noncontrolling interests	2,492	0	4,877	0
Net income attributable to IFF stockholders	136,377	99,149	245,206	228,564
Other comprehensive (loss) income, after tax:
Foreign currency translation adjustments	(14,014)	(85,264)	28,363	(70,461)
Gains on derivatives qualifying as hedges	415	10,455	318	9,926
Pension and postretirement net liability	2,594	2,890	5,187	5,519
Net current period other comprehensive income (loss)	(11,005)	(71,919)	33,868	(55,016)
Comprehensive income attributable to IFF stockholders	$ 125,372	$ 27,230	$ 279,074	$ 173,548
Net income per share - basic (in dollars per share)	$ 1.21	$ 1.25	$ 2.19	$ 2.89
Net income per share - diluted (in dollars per share)	$ 1.20	$ 1.25	$ 2.16	$ 2.87
Average number of shares outstanding - basic (in shares)	111,996	79,065	111,930	79,041
Average number of shares outstanding - diluted (in shares)	112,872	79,303	113,131	79,347