Supplemental Information (Sale of Other Assets) (Details) - Disposal Group, Disposed of by Sale, Not Discontinued Operations - Hersham Regional Office - USD ($) $ in Millions	1 Months Ended	3 Months Ended	9 Months Ended
	Jun. 30, 2025	Jun. 30, 2025	Jun. 30, 2025
Disclosures by Disposal Group [Line Items]
Proceeds from sale of other assets	$ 37.7
Gain on sale of other assets		$ 31.3	$ 31.3
Gain on sale of other assets, net of tax		$ 23.8	$ 23.8