DESCRIPTION OF THE PLAN (Details) - EBP 001 - USD ($)	12 Months Ended
Dec. 31, 2025	Dec. 31, 2024
EBP, Description of Plan [Line Items]
Participant contribution, automatic, election period	60 days
Participant contribution, automatic, annual increase deferral rate	1.00%
Participant contribution, pretax, maximum annual compensation to total compensation, percent	90.00%
Employer contribution, matching percentage	100.00%
Employer contribution, participant compensation matched, percent	6.00%
Requisite service period	3 years
Forfeited nonvested account, decrease from administrative expense	$ 145,000	$ 71,000
Forfeited nonvested account, decrease from employer contribution	2,592,000	1,571,000
Forfeited nonvested account	$ 107,000	$ 1,014,000
Investment, transfer increment, percent	0.01
IFF Common Stock
EBP, Description of Plan [Line Items]
Participant contribution, investment, fund contribution to total contributions, percent	0.20
Vanguard Federal Money Market Fund
EBP, Description of Plan [Line Items]
Investment, assets invested in government securities, threshold percentage	80.00%
Investment, maximum dollar-weighted average maturity, days	60 days
Investment, maximum dollar-weighted average life, days	120 days
Investment, assets invested in government securities, percentage	100.00%
Minimum
EBP, Description of Plan [Line Items]
Participant contribution, automatic, deferral rate	3.00%
Maximum
EBP, Description of Plan [Line Items]
Participant contribution, automatic, deferral rate	9.00%

EBP, Investment, Assets Invested In Government Securities, Minimum Threshold Percentage

No definition available.

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- Definition

EBP, Investment, Assets Invested In Government Securities, Percentage

+ References

No definition available.

+ Details

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Namespace Prefix:	iff_
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Period Type:	duration

- Definition

EBP, Investment, Maximum Dollar-Weighted Average Life, Days

+ References

No definition available.

+ Details

Name:	iff_EBPInvestmentMaximumDollarWeightedAverageLifeDays
Namespace Prefix:	iff_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

EBP, Investment, Maximum Dollar-Weighted Average Maturity, Days

+ References

No definition available.

+ Details

Name:	iff_EBPInvestmentMaximumDollarWeightedAverageMaturityDays
Namespace Prefix:	iff_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

EBP, Investment, Transfer Increment, Percentage

+ References

No definition available.

+ Details

Name:	iff_EBPInvestmentTransferIncrementPercentage
Namespace Prefix:	iff_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Annual increase in percentage of eligible compensation contributed for participant automatically enrolled in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) until the contribution reaches maximum threshold.

+ References

No definition available.

+ Details

Name:	iff_EBPParticipantContributionAutomaticAnnualIncreaseDeferralRate
Namespace Prefix:	iff_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

EBP, Participant Contribution, Automatic, Election Period

+ References

No definition available.

+ Details

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Namespace Prefix:	iff_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

EBP, Participant Contribution, Investment, Fund Contribution to Total Contribution, Threshold Percentage

+ References

No definition available.

+ Details

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Namespace Prefix:	iff_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

EBP, Requisite Service Period

+ References

No definition available.

+ Details

Name:	iff_EBPRequisiteServicePeriod
Namespace Prefix:	iff_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478416/962-205-50-1

+ Details

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Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of employer matching contribution on eligible participant contribution to employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanEmployerContributionMatchingPercentage
Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of participant compensation eligible for employer matching contribution for participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

+ Details

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Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of plan asset, in forfeited nonvested account, no longer allocated to participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanForfeitedNonvestedAccount
Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Amount of decrease in forfeited nonvested account of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) from administrative expense.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (j)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478416/962-205-50-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-04(5)(c))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

+ Details

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Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of decrease in forfeited nonvested account of employee stock purchase, saving, or similar plan (employee benefit plan (EBP)) from employer contribution.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 962
-SubTopic 325
-Name Accounting Standards Codification
-Section 55
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478873/962-325-55-17

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (j)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478416/962-205-50-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 962
-SubTopic 205
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6A-04(5)(c))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477804/962-205-S99-1

+ Details

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Namespace Prefix:	us-gaap-ebp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Percentage of eligible compensation contributed for participant automatically enrolled in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)).

+ References

+ Details

Name:	us-gaap-ebp_EmployeeBenefitPlanParticipantContributionAutomaticDeferralRate
Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of maximum pretax annual compensation that participant in employee stock purchase, saving, or similar plan (employee benefit plan (EBP)), is permitted to contribute to total pretax annual compensation.

+ References

+ Details

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Namespace Prefix:	us-gaap-ebp_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Details

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Namespace Prefix:
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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- Details

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