Supplemental Information (Sale of Business) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	Apr. 30, 2025	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Disclosures by Disposal Group [Line Items]
Gain on sale of business		$ 0.0	$ 67.3	$ 0.0	$ 67.3
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Singapore Subsidiary
Disclosures by Disposal Group [Line Items]
Proceeds from divestiture of businesses	$ 104.3
Gain on sale of business			67.3		67.3
Gain (loss) on sale of business, net of tax			$ 51.9		$ 51.9
Singapore Subsidiary
Disclosures by Disposal Group [Line Items]
Subsidiary, ownership percentage	100.00%