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Restructuring and Other Charges - Narrative (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended		24 Months Ended
	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges	$ 5	$ 14	$ 15	$ 49
IFF Productivity Program
Restructuring Cost and Reserve [Line Items]
Additional Charges (Reversals), Net			15
IFF Productivity Program \| Minimum \| Taste, Food Ingredients, Health And Biosciences, And Scent
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	85		85		$ 85
IFF Productivity Program \| Maximum \| Taste, Food Ingredients, Health And Biosciences, And Scent
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	95		95		95
Severance \| IFF Productivity Program
Restructuring Cost and Reserve [Line Items]
Additional Charges (Reversals), Net			14		81
Restructuring Costs	$ 14		$ 49
Fixed Asset Write Down [Member] \| IFF Productivity Program
Restructuring Cost and Reserve [Line Items]
Restructuring Costs					$ 2