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Assets and Liabilities, at Fair Value - Narrative (Details) - Senior Secured Notes due 2031 - USD ($) $ in Millions	Dec. 31, 2024	Sep. 30, 2024	Mar. 01, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Senior secured notes	$ 543.3	$ 543.1
Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stated interest rate (as a percent)	7.875%		7.875%
Level 2 \| Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt, fair value	$ 575.0