Consolidated Statements of Shareholders’ Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock [Member]	Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income [Member]
Beginning balance at Dec. 31, 2013	$ 2,051.5	$ 5.6	$ 694.8	$ 1,215.8	$ 135.3
Beginning Balance, shares at Dec. 31, 2013		55.7
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	114.5			114.5
Other Comprehensive Income (Loss), Net of Tax	87.4				87.4
Cash Dividends to Shareholders	(51.8)			(51.8)
Repurchases of Common Stock	$ (115.5)	$ (0.4)	(40.2)	(74.9)
Repurchases of Common Stock, shares	(3.2)	(3.2)
Equity-based Compensation Cost	$ 6.4		6.4
Equity-based Awards, Net of Shares Exchanged	(1.8)		(0.9)	(0.9)
Equity-based Awards, Net of Shares Exchanged, shares		(0.1)
Ending Balance, shares at Dec. 31, 2014		52.4
Ending balance at Dec. 31, 2014	2,090.7	$ 5.2	660.1	1,202.7	222.7
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	85.7			85.7
Other Comprehensive Income (Loss), Net of Tax	(98.4)				(98.4)
Cash Dividends to Shareholders	(49.7)			(49.7)
Repurchases of Common Stock	$ (43.5)	$ (0.1)	(15.5)	(27.9)
Repurchases of Common Stock, shares	(1.2)	(1.2)
Equity-based Compensation Cost	$ 6.5		6.5
Equity-based Awards, Net of Shares Exchanged	1.1		2.9	(1.8)
Equity-based Awards, Net of Shares Exchanged, shares		0.1
Ending Balance, shares at Dec. 31, 2015		51.3
Ending balance at Dec. 31, 2015	1,992.4	$ 5.1	654.0	1,209.0	124.3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	16.8			16.8
Other Comprehensive Income (Loss), Net of Tax	12.7				12.7
Cash Dividends to Shareholders	(49.2)			(49.2)
Repurchases of Common Stock	$ (3.8)	$ 0.0	(1.8)	(2.0)
Repurchases of Common Stock, shares	(0.1)	(0.1)
Equity-based Compensation Cost	$ 4.7		4.7
Equity-based Awards, Net of Shares Exchanged	1.6		3.4	(1.8)
Equity-based Awards, Net of Shares Exchanged, shares		0.1
Ending Balance, shares at Dec. 31, 2016		51.3
Ending balance at Dec. 31, 2016	$ 1,975.2	$ 5.1	$ 660.3	$ 1,172.8	$ 137.0