Unaudited Condensed Consolidated Statement Of Shareholders' Equity (USD $) In Millions, except Share data, unless otherwise specified	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]
BALANCE at Dec. 31, 2014	$ 2,072.1us-gaap_StockholdersEquity	$ 1.6	$ 61.8	$ 3,756.6	$ (1,747.9)
BALANCE, shares at Dec. 31, 2014		163,562,149
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	111.5us-gaap_NetIncomeLoss			111.5
Repurchases of common stock	(9.6)				(9.6)
Stock-based compensation expense	11.1		11.1
Shares awarded under stock-based compensation plans, including income tax benefit of $8.1	20.5		(6.0)		26.5
BALANCE at Mar. 31, 2015	$ 2,205.6us-gaap_StockholdersEquity	$ 1.6	$ 66.9	$ 3,868.1	$ (1,731.0)
BALANCE, shares at Mar. 31, 2015		163,562,149

This element represents the amount of recognized equity-based compensation during the period, that is, the amount recognized as expense in the income statement (or as asset if compensation is capitalized). Alternate captions include the words "stock-based compensation".

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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- Definition

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

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- Definition

Value of stock (or other type of equity) issued during the period as a result of any equity-based compensation plan other than an employee stock ownership plan (ESOP), net of stock value of such awards forfeited. Stock issued could result from the issuance of restricted stock, the exercise of stock options, stock issued under employee stock purchase plans, and/or other employee benefit plans.

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