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, 2021	$ 519.7	$ 0.6	$ 561.3	$ 1,011.4	$ (944.0)	$ (109.6)	[1]
Balance at Dec. 31, 2021		47,302,299			15,472,856
Stock issuance, net, shares		100,677
Cash dividends - per common share	(22.0)			(22.0)
Share-based employee compensation	4.4		4.4
Net earnings	96.6			96.6
Other comprehensive income (loss)	14.1					14.1
Acquisition of treasury stock	(85.0)				$ (85.0)
Acquisition of treasury stock, shares		(940,155)			940,155
Ending Balance at Jun. 30, 2022	527.8	$ 0.6	565.7	1,086.0	$ (1,029.0)	(95.5)	[1]
Balance at Jun. 30, 2022		46,462,821			16,413,011
Beginning Balance at Mar. 31, 2022	537.6	$ 0.6	563.9	1,044.8	$ (974.0)	(97.7)	[1]
Balance at Mar. 31, 2022		47,018,645			15,773,861
Stock issuance, net, shares		83,326
Cash dividends - per common share	(11.0)			(11.0)
Share-based employee compensation	1.8		1.8
Net earnings	52.2			52.2
Other comprehensive income (loss)	2.2					2.2
Acquisition of treasury stock	(55.0)				$ (55.0)
Acquisition of treasury stock, shares		(639,150)			639,150
Ending Balance at Jun. 30, 2022	527.8	$ 0.6	565.7	1,086.0	$ (1,029.0)	(95.5)	[1]
Balance at Jun. 30, 2022		46,462,821			16,413,011
Beginning Balance at Dec. 31, 2022	$ 535.0	$ 0.6	573.6	1,169.9	$ (1,109.0)	(100.1)	[1]
Balance at Dec. 31, 2022	45,572,185	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 earnings	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 at Jun. 30, 2023	44,823,285	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 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 earnings	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 at Jun. 30, 2023	44,823,285	44,823,285			18,175,262

[1] Amounts are net of tax