Condensed Consolidated Statements of Shareholders' Equity - USD ($) $ in Millions	Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Treasury Stock	AOCI Attributable to Parent
Beginning Balance at Dec. 31, 2022	$ 535.0	$ 0.6	$ 573.6	$ 1,169.9	$ (1,109.0)	$ (100.1)	[1]
Balance, shares at Dec. 31, 2022		45,572,185			17,364,635
Stock issuance, net, shares		61,745			(18)
Cash dividends - per common share	(23.3)			(23.3)
Share-based employee compensation	6.8		6.8
Net Income (Loss)	107.5			107.5
Other comprehensive income (loss)	(1.7)					(1.7)
Acquisition of treasury stock	(57.6)				$ (57.6)
Acquisition of treasury stock, shares		(810,645)			810,645
Ending Balance at Jun. 30, 2023	566.7	$ 0.6	580.4	1,254.1	$ (1,166.6)	(101.8)	[1]
Balance, shares at Jun. 30, 2023		44,823,285			18,175,262
Beginning Balance at Mar. 31, 2023	544.8	$ 0.6	577.2	1,205.5	$ (1,136.3)	(102.2)	[1]
Balance, shares at Mar. 31, 2023		45,217,244			17,731,828
Stock issuance, net, shares		49,417			58
Cash dividends - per common share	(11.6)			(11.6)
Share-based employee compensation	3.2		3.2
Net Income (Loss)	60.2			60.2
Other comprehensive income (loss)	0.4					0.4
Acquisition of treasury stock	(30.3)				$ (30.3)
Acquisition of treasury stock, shares		(443,376)			443,376
Ending Balance at Jun. 30, 2023	566.7	$ 0.6	580.4	1,254.1	$ (1,166.6)	(101.8)	[1]
Balance, shares at Jun. 30, 2023		44,823,285			18,175,262
Beginning Balance at Dec. 31, 2023	$ 591.8	$ 0.6	591.7	1,346.6	$ (1,242.4)	(104.7)	[1]
Balance, shares at Dec. 31, 2023	43,902,061	43,902,061			19,152,279
Stock issuance, net, shares		112,089
Cash dividends - per common share	$ (24.9)			(24.9)
Share-based employee compensation	3.4		3.4
Net Income (Loss)	125.8			125.8
Other comprehensive income (loss)	(1.8)					(1.8)
Acquisition of treasury stock	(25.3)				$ (25.3)
Acquisition of treasury stock, shares		(226,393)			226,393
Ending Balance at Jun. 30, 2024	$ 669.0	$ 0.6	595.1	1,447.5	$ (1,267.7)	(106.5)	[1]
Balance, shares at Jun. 30, 2024	43,787,757	43,787,757			19,378,672
Beginning Balance at Mar. 31, 2024	$ 626.8	$ 0.6	595.3	1,394.1	$ (1,257.6)	(105.6)	[1]
Balance, shares at Mar. 31, 2024		43,777,371			19,294,861
Stock issuance, net, shares		94,197
Cash dividends - per common share	(12.5)			(12.5)
Share-based employee compensation	(0.2)		(0.2)
Net Income (Loss)	65.9			65.9
Other comprehensive income (loss)	(0.9)					(0.9)
Acquisition of treasury stock	(10.1)				$ (10.1)
Acquisition of treasury stock, shares		(83,811)			83,811
Ending Balance at Jun. 30, 2024	$ 669.0	$ 0.6	$ 595.1	$ 1,447.5	$ (1,267.7)	$ (106.5)	[1]
Balance, shares at Jun. 30, 2024	43,787,757	43,787,757			19,378,672

[1] (1) Amounts are net of tax.