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Amount of stock repurchase plan authorized.

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- Definition

Amount remaining of a stock repurchase plan authorized.

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- Definition

Total cost of shares repurchased divided by the total number of shares repurchased.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 30

-Section 45

-Paragraph 1

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

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Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

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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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Share Repurchases - Additional information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended	1 Months Ended
	Mar. 31, 2015	Apr. 30, 2015	Nov. 04, 2010	Apr. 14, 2015
Accelerated Share Repurchases [Line Items]
Purchase of treasury stock (in shares)	891us-gaap_TreasuryStockSharesAcquired
Purchase of treasury stock	$ 70,063
Purchase of treasury stock, average price per share	$ 78.60
Share repurchase program, authorized amount			274,056
Subsequent Event
Accelerated Share Repurchases [Line Items]
Purchase of treasury stock (in shares)		176
Purchase of treasury stock		14,050
Purchase of treasury stock, average price per share		$ 79.96
Share repurchase program, authorized amount				725,944
Share repurchase program, outstanding authorizations available for share repurchase				$ 1,000,000