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Common Stock Available for Issuance, Value Remaining

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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Percentage of vesting of award under share-based payment arrangement.

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Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended			6 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2025	Mar. 31, 2024
Class of Stock [Line Items]
Equity Securities Registered, Value	$ 750.0			$ 750.0
At-the-market Equity Offering Program, Common Stock Available for Issuance	300.0			300.0
Common Stock, Shares Authorized	750.0			750.0
Stock-based compensation expense	1.7	$ 1.8		$ 4.3	$ 2.7
October Two Thousand Twenty Four Grant \| Performance Shares
Class of Stock [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period				99,097
Stock-based compensation expense	0.3			$ 0.6
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value				$ 35.20
October Two Thousand Twenty Four Grant \| Performance Shares \| Minimum
Class of Stock [Line Items]
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage				0.00%
October Two Thousand Twenty Four Grant \| Performance Shares \| Maximum
Class of Stock [Line Items]
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage				200.00%
First Quarter Two Thousand Twenty Five time-based RSU Grants \| Time-Based RSU
Class of Stock [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period				306,300
Stock-based compensation expense	1.4			$ 3.7
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value				$ 29.00
First Quarter Two Thousand Twenty Five time-based RSU Grants \| Time-Based RSU \| Retirement Eligible
Class of Stock [Line Items]
Stock-based compensation expense	$ 1.1		$ 0.7	$ 1.1	$ 0.7