v3.25.1
Assets and Liabilities, at Fair Value - Narrative (Details) - Senior Secured Notes due 2031 - USD ($)
$ in Millions
Mar. 31, 2025
Sep. 30, 2024
Mar. 01, 2024
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Carrying value $ 543.6 $ 543.1  
Senior Notes      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Debt instrument, interest rate, stated percentage     7.875%
Senior Notes | Level 2      
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]      
Long-term debt, fair value $ 574.1