MARKETING AGREEMENT - Net Commission Earned Under the Marketing Agreement (Details) - USD ($) $ in Millions	12 Months Ended
Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Marketing Agreement [Line Items]
Contribution expenses	$ (2,618.7)	$ (2,708.3)	$ (2,891.1)
Monsanto Marketing Agreement
Marketing Agreement [Line Items]
Gross commission	90.8	75.7	83.4
Contribution expenses	(18.0)	(18.0)	(18.0)
Net commission	72.8	57.7	65.4
Reimbursements associated with Roundup® marketing agreement	91.2	82.5	67.9
Total net sales associated with Roundup® marketing agreement	$ 164.0	$ 140.2	$ 133.3

The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(2)(d))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(2)(a))
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483621/220-10-S99-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 924
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 11.L)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479941/924-10-S99-1

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Balance Type:	debit
Period Type:	duration