Schedule of Unrecognized Compensation Cost and Weighted Average Period of Recognition (Detail) $ in Thousands	9 Months Ended
Oct. 31, 2015 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Unrecognized Compensation Cost	$ 51,320
Weighted Average Years	3 years 1 month 6 days
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Unrecognized Compensation Cost	$ 499
Weighted Average Years	7 months 6 days
Stock Appreciation Rights (SARs)
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Unrecognized Compensation Cost	$ 641
Weighted Average Years	1 year 10 months 24 days
Performance Stock Units
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Unrecognized Compensation Cost	$ 50,180
Weighted Average Years	3 years 1 month 6 days
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Weighted Average Years	0 years

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

No definition available.

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- Definition

Unrecognized cost of unvested share-based compensation awards.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (i)

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

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- Definition

Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

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