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Derivative Financial Instruments and Fair Value Measurements - Fair Value Measurements - Changes in fair value of the Company's Level 3 investment assets (Details) - Credit facility investment including accrued interest - Level 3 - Fair Value, Measurements, Recurring $ in Millions	12 Months Ended
	Sep. 30, 2024 USD ($)
Derivative financial instruments
Investment Gains/(Losses)	$ 0.5
Interest Earned	0.5
Purchases	32.5
Sales	(11.6)
Ending Balance	$ 21.9

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