Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions	Total	Par	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock, Common [Member]
Beginning Balance at Dec. 31, 2020	$ 1,510.2	$ 1.1	$ 849.7	$ 1,996.4	$ (59.6)	$ (1,277.4)
Increase (Decrease) in Stockholders' Equity
Net income	16.1			16.1
Change in other comprehensive income (loss) - net of tax	(66.9)				(66.9)
Stock-based activity	26.1		28.9			(2.8)
Ending Balance at Dec. 31, 2021	1,485.5	1.1	878.6	2,012.5	(126.5)	(1,280.2)
Increase (Decrease) in Stockholders' Equity
Net income	126.3			126.3
Dividends on common stock	(33.9)			(33.9)
Change in other comprehensive income (loss) - net of tax	(47.9)				(47.9)
Stock-based activity	24.2		26.4			(2.2)
Ending Balance at Dec. 31, 2022	1,554.2	1.1	905.0	2,104.9	(174.4)	(1,282.4)
Increase (Decrease) in Stockholders' Equity
Net income	105.7			105.7
Dividends on common stock	(41.9)			(41.9)
Repurchases of common stock	(30.1)					(30.1)
Change in other comprehensive income (loss) - net of tax	100.3				100.3
Stock-based activity	28.3		31.8			(3.5)
Ending Balance at Dec. 31, 2023	$ 1,716.5	$ 1.1	$ 936.8	$ 2,168.7	$ (74.1)	$ (1,316.0)