Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Millions		Total	Common Stock [Member]		Additional Paid-In Capital [Member]		Retained Earnings [Member]		Accumulated Other Comprehensive Loss [Member]		Deferred Compensation [Member]		Treasury Stock, Common
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares Held In Trust For Deferred Compensation Plan		108,000
Common Stock, Dividends, Per Share, Declared		$ 0.590
Beginning Balances (shares) at Dec. 31, 2023	[1],[2]		22,235,000
Beginning Balances at Dec. 31, 2023		$ 1,246.1	$ 10.8	[1]	$ 749.4		$ 488.7		$ (2.8)		$ 9.1		$ (9.1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income		46.2					46.2
Other comprehensive income (loss)		1.0							1.0
Other Comprehensive Income (Loss), Net of Tax		1.0
Dividend declared							(13.2)
Retirement savings plan and dividend reinvestment plan (shares)	[1],[2],[3]		3,000
Stock Issued During The Period Value Retirement Savings Plan And Dividend Reinvestment Plan	[3]		$ 0.0	[1]	0.3
Share-based compensation (shares)	[1],[2],[4],[5]		29,000
Share-based compensation and tax benefit	[4],[5]		$ 0.0	[1]	0.5
Treasury stock activities	[2]										0.5		(0.5)
Ending Balances (shares) at Mar. 31, 2024	[1],[2]		22,267,000
Ending Balances at Mar. 31, 2024		$ 1,280.9	$ 10.8	[1]	750.2		521.7		(1.8)		9.6		(9.6)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation		14,000
Shares Held In Trust For Deferred Compensation Plan		111,000
Preferred Stock, Shares Authorized		2,000,000,000
Preferred Stock, Par or Stated Value Per Share		$ 10.00
Shares Held In Trust For Deferred Compensation Plan		114,000
Common Stock, Dividends, Per Share, Declared		$ 0.640
Beginning Balances (shares) at Dec. 31, 2024	[1],[2],[6]		22,899,000
Beginning Balances at Dec. 31, 2024		$ 1,390.2	$ 11.1	[1],[6]	830.5	[6]	550.3	[6]	(1.7)	[6]	9.8	[6]	(9.8)	[6]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income		50.9					50.9
Other comprehensive income (loss)		(0.6)							(0.6)
Other Comprehensive Income (Loss), Net of Tax		(0.6)
Dividend declared							(14.8)
Retirement savings plan and dividend reinvestment plan (shares)	[1],[2],[3]		161,000
Stock Issued During The Period Value Retirement Savings Plan And Dividend Reinvestment Plan	[3]		$ 0.1	[1]	19.7
Share-based compensation (shares)	[1],[2],[4],[5]		29,000
Share-based compensation and tax benefit	[4],[5]		$ 0.0	[1]	1.8
Treasury stock activities	[2]										2.4		(2.4)
Ending Balances (shares) at Mar. 31, 2025	[1],[2]		23,089,000
Ending Balances at Mar. 31, 2025		$ 1,447.3	$ 11.2	[1]	$ 852.0		$ 586.4		$ (2.3)		$ 12.2		$ (12.2)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation		8,000
Stock Issued, Value, During The Period Shares Retirement Savings Plan And Dividend Reinvestment Plan	[3]	$ 19.8
Preferred Stock, Shares Authorized		2,000,000
Preferred Stock, Par or Stated Value Per Share		$ 10.00
Shares Held In Trust For Deferred Compensation Plan		126,000

[1] 2.0 million shares of preferred stock at $0.01 par value have been authorized. No preferred shares have been issued or are outstanding; accordingly, no information has been included in the Condensed Consolidated Statements of Stockholders’ Equity.    

[2] Includes 126 thousand, 114 thousand, 111 thousand, and 108 thousand shares at March 31, 2025, December 31, 2024, March 31, 2024 and December 31, 2023, respectively, held in a Rabbi Trust related to our Non-Qualified Deferred Compensation Plan.

[3] Includes shares issued under the Retirement Savings Plan, DRIP and/or ATM program, as applicable.

[4] Includes amounts for shares issued for directors’ compensation.

[5] The shares issued under the SICP are net of shares withheld for employee taxes. For the three months ended March 31, 2025 and 2024, we withheld 8 thousand and 14 thousand shares, respectively, for employee taxes.

[6]