Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Mar. 31, 2023	Nov. 18, 2021	Oct. 08, 2021
Class of Stock [Line Items]
Equity Securities Registered, Value						$ 750.0
At-the-market Equity Offering Program, Common Stock Available for Issuance	$ 278.1		$ 278.1		$ 300.0
At-the-market Equity Offering Program, Common Stock Issued			546,174
Stock Issued During Period, Value, New Issues	19.7		$ 19.7
Payments of Stock Issuance Costs			0.4
Common Stock, Shares Authorized	$ 728.1		728.1
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	154,034
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value	$ 40.19
Stock-based compensation expense	$ 1.8	$ 1.9	2.7	$ 2.5
Common Stock
Class of Stock [Line Items]
Stock Issued During Period, Value, New Issues	0.5
Additional Paid-in Capital
Class of Stock [Line Items]
Stock Issued During Period, Value, New Issues	19.2
Retained Earnings
Class of Stock [Line Items]
Stock Issued During Period, Value, New Issues	0.0
Noncontrolling Interest
Class of Stock [Line Items]
Stock Issued During Period, Value, New Issues	0.0
Retirement Eligible
Class of Stock [Line Items]
Stock-based compensation expense	$ 0.7	$ 1.3	$ 0.7	$ 1.3