Note 10 - Information by Operating Segment - Net Economic Earnings to Net Income (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Net Income	$ 85.1	$ 91.0
Fair value and timing adjustments	(5.2)	(7.8)
Acquisition activities	1.9	0.0
Income tax adjustments	0.9	1.9
Net Economic Earnings	$ 82.7	$ 85.1