CONSOLIDATED STATEMENTS OF EQUITY (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Shares Issued During Period, New Issues		84,547
Share-Based Payment Arrangement, Decrease for Tax Withholding Obligation	$ (0.1)	$ (0.1)
Issuance of common stock (84,547 shares)		1.7
Net income	20.8	40.5
Issuances of common stock, Value	0.0	0.0
Stock-based compensation expense	0.6	0.4
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 1,220.6	$ 1,058.4
Common Stock
Common Stock, Shares, Outstanding	49,772,555	49,675,768
Share-Based Payment Arrangement, Decrease for Tax Withholding Obligation	$ 0.0	$ 0.0
Issuance of common stock (84,547 shares)		0.1
Net income	0.0	0.0
Issuances of common stock, Value	0.0	0.0
Stock-based compensation expense	0.0	0.0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 49.8	$ 49.7
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture	11,075	10,832
Additional Paid-in Capital
Share-Based Payment Arrangement, Decrease for Tax Withholding Obligation	$ (0.1)	$ (0.1)
Issuance of common stock (84,547 shares)		1.6
Net income	0.0	0.0
Issuances of common stock, Value	0.0	0.0
Stock-based compensation expense	0.6	0.4
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	641.1	638.1
Retained Earnings
Share-Based Payment Arrangement, Decrease for Tax Withholding Obligation	0.0	0.0
Issuance of common stock (84,547 shares)		0.0
Net income	20.8	40.5
Issuances of common stock, Value	0.0	0.0
Stock-based compensation expense	0.0	0.0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	528.7	369.6
Noncontrolling Interest
Share-Based Payment Arrangement, Decrease for Tax Withholding Obligation	0.0	0.0
Issuance of common stock (84,547 shares)		0.0
Net income	0.0	0.0
Issuances of common stock, Value	0.0	0.0
Stock-based compensation expense	0.0	0.0
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 1.0	$ 1.0