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	3 Months Ended
Dec. 31, 2024	Dec. 31, 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 or Comprehensive Income [Extensible Enumeration]	Selling, general and administrative	Selling, general and administrative
Level 3
Total gains:
Included in earnings	$ 109	$ 0
Level 3 \| Debt Securities
Reconciliation of changes in the fair value of our financial assets
Assets at beginning of period	29,294	37,440
Accrued interest	455	433
Total gains:
Included in earnings	0	(5)
Assets at end of period	29,749	37,868
Level 3 \| Equity Securities Without Readily Determinable Fair Value
Reconciliation of changes in the fair value of our financial assets
Assets at beginning of period	30,090	28,232
Purchases	646	291
Total gains:
Assets at end of period	$ 30,845	$ 28,523

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis Accrued Interest

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Indicates line item in statement of income or comprehensive income that includes unrealized gain (loss) from asset measured at fair value 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 gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3).

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- Definition

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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- Definition

Fair value 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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