MARKETING AGREEMENT - Net Commission Earned Under the Marketing Agreement (Details) - USD ($) $ in Millions	12 Months Ended
Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Marketing Agreement [Line Items]
Contribution expenses	$ (2,708.3)	$ (2,891.1)	$ (3,431.3)
Monsanto Marketing Agreement
Marketing Agreement [Line Items]
Gross commission	75.7	83.4	94.0
Contribution expenses	(18.0)	(18.0)	(18.0)
Net commission	57.7	65.4	76.0
Reimbursements associated with Roundup® marketing agreement	82.5	67.9	70.8
Total net sales associated with Roundup® marketing agreement	$ 140.2	$ 133.3	$ 146.8

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://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

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),(d))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration