Stock-Based Compensation Plans - Additional Information (Detail)	9 Months Ended	3 Months Ended	9 Months Ended
Sep. 30, 2014 Stock Appreciation Rights (SARs)	Sep. 30, 2014 Stock Appreciation Rights (SARs) Maximum	Mar. 31, 2014 Performance Shares	Sep. 30, 2014 Restricted Stock
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period	3 years		3 years	3 years
Expiration term of stock units		5 years

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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Data Type:	xbrli:durationItemType
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Period Type:	duration