Summary of Significant Accounting Policies (Other Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended			6 Months Ended
	Aug. 02, 2019	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Mar. 31, 2020	Mar. 31, 2019
Accounting Policies [Abstract]
Revenues		$ 723.2		$ 714.2	$ 1,408.2	$ 1,397.7
Sale of businesses	$ 166.6
Professional Fees			$ 4.0
Net Income (Loss) Attributable to Parent		46.9		49.5	86.7	$ 91.7
Net Income		$ 46.9		$ 49.5	$ 86.7
Net Income Attributable to Common Shareholders per Common Share - Basic (usd per share)		$ 0.70		$ 0.74	$ 1.30	$ 1.37
Earnings Per Share, Diluted		$ 0.70		$ 0.74	$ 1.29	$ 1.36