Debt (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended		12 Months Ended
	Oct. 31, 2023	Sep. 30, 2026	Sep. 30, 2025	Sep. 30, 2026	Sep. 30, 2025	Dec. 31, 2025	Jun. 30, 2023	Dec. 31, 2019	Sep. 30, 2015
Debt Instrument [Line Items]
Collateral amount		$ 150.0		$ 150.0
Remaining borrowing capacity		20.0		$ 20.0
UBS Credit Line
Debt Instrument [Line Items]
Spread on interest rate (as a percent)				0.50%		0.50%
UBS Credit Line | Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity							$ 100.0	$ 50.0	$ 50.0
Collateral amount		150.0		$ 150.0
Spread on interest rate (as a percent)	0.50%
Total drawn down		80.0		80.0
Remaining borrowing capacity		20.0		20.0
Interest expense		0.9	$ 1.0	2.7	$ 3.1
Outstanding balance		$ 80.3		$ 80.3		$ 80.3