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Restructuring and Other Charges - Narrative (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended		9 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges	$ 21	$ 2	$ 38	$ 5
IFF Productivity Program
Restructuring Cost and Reserve [Line Items]
Additional Charges (Reversals), Net			38
IFF Productivity Program \| Minimum \| Taste, Food Ingredients, Health And Biosciences, And Scent
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	100		100		$ 100
IFF Productivity Program \| Maximum \| Taste, Food Ingredients, Health And Biosciences, And Scent
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Expected Cost	120		120		120
Employee Severance \| IFF Productivity Program
Restructuring Cost and Reserve [Line Items]
Additional Charges (Reversals), Net	$ 21		$ 38
Restructuring Costs					41
Fixed Asset Write Down [Member] \| IFF Productivity Program
Restructuring Cost and Reserve [Line Items]
Restructuring Costs					$ 20