FAIR VALUE MEASUREMENT OF FINANCIAL INSTRUMENTS - Reconciliation of Changes in Fair Value of Financial Assets and Liabilities Classified as Level 3 (Details) - USD ($) $ in Thousands	12 Months Ended
Sep. 30, 2024	Sep. 30, 2023
Reconciliation of changes in the fair value of our financial assets
Fair Value Asset Recurring Basis Still Held Unrealized Gain Loss Statement Of Income Extensible List Not Disclosed Flag	Included in earnings2	Included in earnings2
Reconciliation of changes in the fair value of our financial liabilities
Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Selling, general and administrative	Selling, general and administrative
Level 3
Reconciliation of changes in the fair value of our financial assets
Assets at beginning of period	$ 28,232	$ 23,745
Purchases	3,870	4,487
Disposals	(616)	0
Included in earnings	(1,396)	0
Assets at end of period	30,090	28,232
Reconciliation of changes in the fair value of our financial liabilities
Liabilities at beginning of period	9,455	4,022
Additions	0	500
Total gains or losses included in earnings	6,670	7,808
Settlements	(16,125)	(2,875)
Liabilities at end of period	0	9,455
Level 3 \| Investment in Galileo, net
Reconciliation of changes in the fair value of our financial assets
Assets at beginning of period	37,440	33,565
Purchases	250	2,122
Accrued interest	1,771	2,434
Included in earnings	(10,167)	(681)
Assets at end of period	$ 29,294	$ 37,440

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Amount of unrealized gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3) and still held.

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of sale of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of gain (loss) recognized in income from liability measured at fair value on recurring basis using unobservable input (level 3).

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Amount of settlements of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Indicates line item in statement of income or comprehensive income that includes gain (loss) from liability measured at fair value using unobservable input (level 3).

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