CONSOLIDATED STATEMENT OF INCOME AND COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
Net sales	$ 1,347,317	$ 1,297,402
Cost of goods sold	781,450	766,143
Gross profit	565,867	531,259
Research and development expenses	85,909	90,596
Selling and administrative expenses	229,714	213,182
Amortization of acquisition-related intangibles	48,350	47,625
Restructuring and other charges, net	4,918	16,174
Losses (gains) on sales of fixed assets	754	(188)
Operating profit	196,222	163,870
Interest expense	32,140	36,572
Other loss (income), net	10,574	(7,278)
Income before taxes	153,508	134,576
Taxes on income	26,297	23,362
Net income	127,211	111,214
Net income attributable to noncontrolling interests	2,604	2,385
Net income attributable to IFF stockholders	124,607	108,829
Other comprehensive (loss) income, after tax:
Foreign currency translation adjustments	(452,278)	42,377
Gains (losses) on derivatives qualifying as hedges	1,447	(97)
Pension and postretirement net liability	3,517	2,593
Net current period other comprehensive income (loss)	(447,314)	44,873
Comprehensive (loss) income attributable to IFF stockholders	$ (322,707)	$ 153,702
Net income per share - basic (in dollars per share)	$ 1.16	$ 0.97
Net income per share - diluted (in dollars per share)	$ 1.15	$ 0.96
Average number of shares outstanding - basic (in shares)	112,082	111,864
Average number of shares outstanding - diluted (in shares)	113,594	113,389