Consolidated Statements of Changes in Shareholders' Equity Statement - USD ($) $ in Millions	Total	AOCI Attributable to Parent [Member]	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]
Common Stock, Shares, Issued			67,300,000
Shares, Issued				(30,700,000)
Stockholders' Equity Attributable to Parent		$ (164.6)		$ (1,214.5)	$ 706.4	$ 2,419.2
Common Stock, Value, Issued			$ 41.6
Dividends Declared [Table Text Block]	1.38
Stock Repurchased During Period, Shares	(1,700,000)
Repurchase of common stock	$ (129.9)
APIC, Share-based Payment Arrangement, Increase for Cost Recognition					10.2
Stock Issued During Period, Shares, New Issues			200,000
Stock Issued During Period, Value, New Issues			$ 0.2
Net income	154.6
Dividends, Common Stock, Cash						(51.7)
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Retained Earnings | Retained Earnings [Member]	39.4
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	$ 24.4
Common Stock, Shares, Issued			67,500,000
Shares, Issued				(31,800,000)
Stockholders' Equity Attributable to Parent		(155.8)		$ (1,297.7)	713.0	2,533.5
Common Stock, Value, Issued			$ 41.8
Dividends Declared [Table Text Block]	0.46
Stock Repurchased During Period, Shares	(600,000)
Repurchase of common stock	$ (46.7)
APIC, Share-based Payment Arrangement, Increase for Cost Recognition					3.6
Stock Issued During Period, Shares, New Issues			0
Stock Issued During Period, Value, New Issues			$ 0.0
Net income	45.1
Dividends, Common Stock, Cash						(17.1)
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Retained Earnings | Retained Earnings [Member]	0.0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	33.2
Common Stock, Shares, Issued			67,500,000
Shares, Issued				(32,400,000)
Stockholders' Equity Attributable to Parent	$ 1,786.5	(189.0)		$ (1,344.4)	716.6	2,561.5
Common Stock, Value, Issued			$ 41.8
Common Stock, Shares, Issued	67,536,794		67,500,000
Shares, Issued				(32,700,000)
Stockholders' Equity Attributable to Parent	$ 1,835.1	(163.6)		$ (1,364.5)	720.1	2,601.3
Common Stock, Value, Issued	$ 41.8		$ 41.8
Dividends Declared [Table Text Block]	1.44
Stock Repurchased During Period, Shares	0
Repurchase of common stock	$ 0.0
APIC, Share-based Payment Arrangement, Increase for Cost Recognition					10.7
Stock Issued During Period, Shares, New Issues			200,000
Stock Issued During Period, Value, New Issues			$ 0.1
Net income	133.5
Dividends, Common Stock, Cash						(52.8)
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Retained Earnings | Retained Earnings [Member]	0.0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	$ (3.4)
Common Stock, Shares, Issued			67,700,000
Shares, Issued				(32,700,000)
Stockholders' Equity Attributable to Parent		(182.5)		$ (1,364.5)	728.8	2,651.7
Common Stock, Value, Issued			$ 41.8
Dividends Declared [Table Text Block]	0.48
Stock Repurchased During Period, Shares	0
Repurchase of common stock	$ 0.0
APIC, Share-based Payment Arrangement, Increase for Cost Recognition					2.0
Stock Issued During Period, Shares, New Issues			0
Stock Issued During Period, Value, New Issues			$ 0.1
Net income	47.9
Dividends, Common Stock, Cash						(17.6)
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Retained Earnings | Retained Earnings [Member]	0.0
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	$ (22.3)
Common Stock, Shares, Issued	67,685,423		67,700,000
Shares, Issued				(32,700,000)
Stockholders' Equity Attributable to Parent	$ 1,930.0	$ (160.2)		$ (1,364.5)	$ 730.8	$ 2,682.0
Common Stock, Value, Issued	$ 41.9		$ 41.9