Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions	Total	Par	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock
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 (loss)	(14.0)			(14.0)
Change in other comprehensive (loss)- net of tax	(19.1)				(19.1)
Stock based compensation	9.8		11.8			(2.0)
Ending Balance at Mar. 31, 2021	1,486.9	1.1	861.5	1,982.4	(78.7)	(1,279.4)
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 (loss)	(2.8)
Change in other comprehensive (loss)- net of tax	(34.2)
Ending Balance at Sep. 30, 2021	1,494.3	1.1	873.4	1,993.6	(93.8)	(1,280.0)
Beginning Balance at Mar. 31, 2021	1,486.9	1.1	861.5	1,982.4	(78.7)	(1,279.4)
Increase (Decrease) in Stockholders' Equity
Net income (loss)	2.2			2.2
Change in other comprehensive (loss)- net of tax	5.5				5.5
Stock based compensation	8.2		8.2
Ending Balance at Jun. 30, 2021	1,502.8	1.1	869.7	1,984.6	(73.2)	(1,279.4)
Increase (Decrease) in Stockholders' Equity
Net income (loss)	9.0			9.0
Change in other comprehensive (loss)- net of tax	(20.6)				(20.6)
Stock based compensation	3.1		3.7			(0.6)
Ending Balance at Sep. 30, 2021	1,494.3	1.1	873.4	1,993.6	(93.8)	(1,280.0)
Beginning 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 (loss)	17.8			17.8
Dividends paid on common stock	(8.5)			(8.5)
Change in other comprehensive (loss)- net of tax	(17.6)				(17.6)
Stock based compensation	9.9		11.3			(1.4)
Ending Balance at Mar. 31, 2022	1,487.1	1.1	889.9	2,021.8	(144.1)	(1,281.6)
Beginning 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 (loss)	89.3
Change in other comprehensive (loss)- net of tax	(122.6)				(122.6)
Ending Balance at Sep. 30, 2022	1,445.0	1.1	898.9	2,076.4	(249.1)	(1,282.3)
Beginning Balance at Mar. 31, 2022	1,487.1	1.1	889.9	2,021.8	(144.1)	(1,281.6)
Increase (Decrease) in Stockholders' Equity
Net income (loss)	44.7			44.7
Dividends paid on common stock	(8.5)			(8.5)
Change in other comprehensive (loss)- net of tax	(47.2)				(47.2)
Stock based compensation	4.2		4.2
Ending Balance at Jun. 30, 2022	1,480.3	1.1	894.1	2,058.0	(191.3)	(1,281.6)
Increase (Decrease) in Stockholders' Equity
Net income (loss)	26.8			26.8
Dividends paid on common stock	(8.4)			(8.4)
Change in other comprehensive (loss)- net of tax	(57.8)				(57.8)
Stock based compensation	4.1		4.8			(0.7)
Ending Balance at Sep. 30, 2022	$ 1,445.0	$ 1.1	$ 898.9	$ 2,076.4	$ (249.1)	$ (1,282.3)