CONSOLIDATED STATEMENT OF INCOME AND COMPREHENSIVE INCOME - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Net sales	$ 2,465.0	$ 1,347.0
Cost of goods sold	1,711.0	781.0
Gross profit	754.0	566.0
Research and development expenses	143.0	86.0
Selling and administrative expenses	451.0	230.0
Amortization of acquisition-related intangibles	152.0	48.0
Restructuring and other charges, net	4.0	5.0
Losses on sales of fixed assets	0.0	1.0
Operating profit	4.0	196.0
Interest expense	65.0	32.0
Other (income) expense, net	(7.0)	11.0
(Loss) income before taxes	(54.0)	153.0
Taxes on (loss) income	(14.0)	26.0
Net (loss) income	(40.0)	127.0
Net income attributable to noncontrolling interests	2.0	3.0
Net (loss) income attributable to IFF stockholders	(42.0)	124.0
Other comprehensive loss, after tax:
Foreign currency translation adjustments	(417.0)	(452.0)
Gains on derivatives qualifying as hedges	4.0	1.0
Pension and postretirement net liability	9.0	4.0
Net current period other comprehensive income (loss)	(404.0)	(447.0)
Comprehensive loss attributable to IFF stockholders	$ (446.0)	$ (323.0)
Net income per share - basic (in dollars per share)	$ (0.21)	$ 1.16
Net income per share - diluted (in dollars per share)	$ (0.21)	$ 1.15
Average number of shares outstanding - basic (in shares)	206	112
Average number of shares outstanding - diluted (in shares)	206	113