Employee Stock and Savings Plans Summary (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
Jan. 31, 2016	Jan. 31, 2015	Jan. 31, 2014
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award
Equity instruments other than options, nonvested, number	4,117	4,246
Equity instruments other than options, nonvested, weighted average grant date fair value	$ 22.35	$ 19.63
Equity instruments other than options, grants in period	1,711
Weighted average grant date fair value	$ 24.10	$ 21.52	$ 22.42
Equity instruments other than options, vested in period	(1,586)
Equity instruments other than options, vested in period, weighted average grant date fair value	$ 17.35
Equity instruments other than options, forfeited in period	(254)
Equity instruments other than options, forfeitures, weighted average grant date fair value	$ 19.95
Equity instruments other than options, outstanding, weighted average remaining contractual terms	1 year 7 months 13 days
Equity instruments other than options, aggregate intrinsic value, nonvested	$ 71,561
Equity instruments other than options, vested in period, fair value	$ 27,527	$ 22,874	$ 17,736
Equity Option
Share-based Compensation Arrangement by Share-based Payment Award
Options, outstanding, number	2,471	3,152
Options, outstanding, weighted average exercise price	$ 9.66	$ 9.73
Options, grants in period, gross	0
Options, grants in period, weighted average exercise price	$ 0.00
Options, exercises in period	(639)
Options, exercises in period, weighted average exercise price	$ 9.79
Options, forfeitures in period	(26)
Options, forfeitures in period, weighted average exercise price	$ 16.20
Options, expirations in period	(16)
Options, expirations in period, weighted average exercise price	$ 8.26
Options, outstanding, weighted average remaining contractual term	3 years 11 months 23 days
Options, outstanding, intrinsic value	$ 19,085
Options, exercisable, number	2,395
Options, exercisable, weighted average exercise price	$ 9.42
Options, exercisable, weighted average remaining contractual term	3 years 10 months 24 days
Options, exercisable, intrinsic value	$ 19,058
Options, vested and expected to vest, outstanding, number	2,471
Options, vested and expected to vest, outstanding, weighted average exercise price	$ 9.66
Options, vested and expected to vest, outstanding, weighted average remaining contractual term	3 years 11 months 23 days
Options, vested and expected to vest, outstanding, aggregate intrinsic value	$ 19,085
Options, exercises in period, intrinsic value	9,440	$ 4,601	26,769
Proceeds from stock options exercised	$ 6,260	$ 4,636	$ 38,830
Expiry period from date of grant	10 years
Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award
Requisite service period	4 years
Number of shares available for grant	4,181
Omnibus Incentive Plan \| Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award
Requisite service period	3 years
Employee Stock Purchase Plans
Share-based Compensation Arrangement by Share-based Payment Award
Stock issued during period, shares, employee stock purchase plans	1,538	1,389	1,554
Proceeds from issuance of shares under incentive and share-based compensation plans, excluding stock options	$ 26,511	$ 25,642	$ 23,895
Employee stock purchase plan weighted average purchase price	$ 17.24	$ 18.47	$ 15.38
Employee stock purchase plan maximum number of shares per buy date that may be purchased by eligible participants	6
Discounted price from market price offering	85.00%
Available for future purchase employee stock purchase plan shares	3,620

Employee Stock Purchase Plan Maximum Number Of Shares Per Buy Date That May Be Purchased By Eligible Participants

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Share Based Compensation Arrangement By Share Based Payment Award Available For Future Purchase Employee Stock Purchase Plan Shares

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- Definition

The discounted price from the offering date market price or purchase date market price that participants pay for shares purchased under the employee stock purchase plan.

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Share Based Compensation Arrangement By Share Based Payment Award Employee Stock Purchase Plan Weighted Average Purchase Price

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Expiration date from the original grant date for options granted under share based payment awards.

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The cash inflow associated with the amount received from holders to acquire the entity's shares under incentive and share awards other than stock option exercises. This item inherently excludes any excess tax benefit, which the entity may have realized and reported separately.

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The cash inflow associated with the amount received from holders exercising their stock options. This item inherently excludes any excess tax benefit, which the entity may have realized and reported separately.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (j)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event.

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The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

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Weighted average remaining contractual term for equity-based awards excluding options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

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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.

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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- Definition

Number of options or other stock instruments for which the right to exercise has lapsed under the terms of the plan agreements.

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The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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Gross number of share options (or share units) granted during the period.

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No definition available.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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Number of options outstanding, including both vested and non-vested options.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

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Amount by which the current fair value of the underlying stock exceeds the exercise price of fully vested and expected to vest options outstanding.

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As of the balance sheet date, the number of shares into which fully vested and expected to vest stock options outstanding can be converted under the option plan.

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As of the balance sheet date, the weighted-average exercise price for outstanding stock options that are fully vested or expected to vest.

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- Definition

Weighted average price at which option holders acquired shares when converting their stock options into shares.

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No definition available.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options of the plan that expired.

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No definition available.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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No definition available.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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No definition available.

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- Definition

Intrinsic value of equity-based compensation awards not vested. Excludes stock and unit options.

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No definition available.

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Weighted average remaining contractual term for fully vested and expected to vest options outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of shares issued during the period as a result of an employee stock purchase plan.

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Number of share options (or share units) exercised during the current period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
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-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 3: http://www.xbrl.org/2003/role/presentationRef
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-Name Accounting Standards Codification
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-SubTopic 10
-Section 50
-Paragraph 2
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-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 29, 30
-Article 5

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