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, 2019	$ 364.9	$ 0.6	$ 555.7	$ 1,008.2	$ (823.5)	$ (376.1)
Balance, shares at Dec. 31, 2019		47,992,348
Balance, shares at Dec. 31, 2019					14,271,047
Stock issuance, net, shares		335,936
Cash dividends - per common share	(39.3)			(39.3)
Share-based employee compensation	2.0		2.0
Net earnings (loss)	(99.1)			(99.1)
Other comprehensive income (loss)	266.8					266.8
Restricted stock issued to employees in connection with acquisition			(4.0)		$ 4.0
Restricted stock issued to employees in connection with acquisition, shares		94,230			(94,230)
Acquisition of treasury stock	(44.4)				$ (44.4)
Acquisition of treasury stock, shares		(508,693)			508,693
Ending Balance at Dec. 31, 2020	450.9	$ 0.6	553.7	869.8	$ (863.9)	(109.3)
Balance, shares at Dec. 31, 2020		47,913,821
Balance, shares at Dec. 31, 2020					14,685,510
Stock issuance, net			0.1		$ (0.1)
Stock issuance, net, shares		173,379			2,445
Cash dividends - per common share	(41.6)			(41.6)
Share-based employee compensation	7.5		7.5
Net earnings (loss)	183.2			183.2
Other comprehensive income (loss)	(0.3)					(0.3)
Acquisition of treasury stock	(80.0)				$ (80.0)
Acquisition of treasury stock, shares		(784,901)			784,901
Ending Balance at Dec. 31, 2021	$ 519.7	$ 0.6	561.3	1,011.4	$ (944.0)	(109.6)
Balance, shares at Dec. 31, 2021	47,302,299	47,302,299
Balance, shares at Dec. 31, 2021					15,472,856
Stock issuance, net, shares		159,628			2,037
Cash dividends - per common share	$ (44.4)			(44.4)
Share-based employee compensation	12.3		12.3
Net earnings (loss)	202.9			202.9
Other comprehensive income (loss)	9.5					9.5
Acquisition of treasury stock	(165.0)				$ (165.0)
Acquisition of treasury stock, shares		(1,889,742)			1,889,742
Ending Balance at Dec. 31, 2022	$ 535.0	$ 0.6	$ 573.6	$ 1,169.9	$ (1,109.0)	$ (100.1)
Balance, shares at Dec. 31, 2022	45,572,185	45,572,185
Balance, shares at Dec. 31, 2022					17,364,635