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Number of shares of stock issued as of the balance sheet date, including shares that had been issued and were previously outstanding but which are now held in the treasury.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section 50

-Paragraph 2

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Number of shares issued during the period as a result of the conversion of convertible securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

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Number of shares (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 any shares forfeited. Shares 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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Number of shares that have been repurchased during the period and are being held in treasury.

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Changes in Preferred Stock, Common Stock and Treasury Stock (Detail) In Millions, unless otherwise specified	25 Months Ended	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stock Option Activity And Changes [Line Items]
Common stock repurchases	2.2us-gaap_TreasuryStockSharesAcquired
Preferred Stock
Stock Option Activity And Changes [Line Items]
Beginning Balance		2.6			2.6
Preferred stock conversion		(2.6)
Ending Balance				2.6	2.6
Common Stock
Stock Option Activity And Changes [Line Items]
Beginning Balance		45.1	44.3	43.8
Stock-based compensation		0.4	0.8	0.5
Preferred stock conversion		6.9
Ending Balance	52.4	52.4	45.1	44.3
Treasury Stock
Stock Option Activity And Changes [Line Items]
Beginning Balance		1.1	0.4	0.3
Common stock repurchases		1.6	0.6
Stock-based compensation			0.1	0.1
Ending Balance	2.7	2.7	1.1	0.4