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, 2020	$ 450.9	$ 0.6	$ 553.7	$ 869.8	$ (863.9)	$ (109.3)
Balance at Dec. 31, 2020		47,913,821
Balance at Dec. 31, 2020					14,685,510
Stock issuance, net, shares		40,278
Cash dividends - per common share	(10.2)			(10.2)
Share-based employee compensation	2.9		2.9
Net earnings	35.4			35.4
Other comprehensive income	4.6					4.6
Acquisition of treasury stock	(10.0)				$ (10.0)
Acquisition of treasury stock, shares		(125,635)			125,635
Ending Balance at Mar. 31, 2021	473.6	$ 0.6	556.6	895.0	$ (873.9)	(104.7)
Balance at Mar. 31, 2021		47,828,464
Balance at Mar. 31, 2021					14,811,145
Beginning Balance at Dec. 31, 2021	$ 519.7	$ 0.6	561.3	1,011.4	$ (944.0)	(109.6)
Balance at Dec. 31, 2021	47,302,299	47,302,299
Balance at Dec. 31, 2021					15,472,856
Stock issuance, net, shares		17,351
Cash dividends - per common share	$ (11.0)			(11.0)
Share-based employee compensation	2.6		2.6
Net earnings	44.4			44.4
Other comprehensive income	11.9					11.9
Acquisition of treasury stock	(30.0)				$ (30.0)
Acquisition of treasury stock, shares		(301,005)			301,005
Ending Balance at Mar. 31, 2022	$ 537.6	$ 0.6	$ 563.9	$ 1,044.8	$ (974.0)	$ (97.7)
Balance at Mar. 31, 2022	47,018,645	47,018,645
Balance at Mar. 31, 2022					15,773,861