Borrowings - Components of Interest and Other Debt Expenses (Details) - 2028 Notes $ in Millions	3 Months Ended
	Dec. 31, 2023 USD ($)
Debt Instrument [Line Items]
Coupon interest	$ 3.8
Amortization of financing costs and discount	0.1
Effect of interest rate swap	0.6
Total interest expense	$ 4.5
Coupon interest rate (net of effect of interest rate swaps)	9.45%