Employee Stock and Savings Plans Summary of Restricted Stock Activity (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
Jan. 31, 2013	Jan. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Nonvested restricted stock units	3,996	3,596
Nonvested restricted stock units granted in period	1,681
Nonvested restricted stock units vested in period	(1,162)
Nonvested restricted stock units forfeited in period	(119)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Additional Disclosures [Abstract]
Weighted average grant date fair value of nonvested restricted stock units	$ 13.39	$ 10.71
Weighted average grant date fair value of nonvested restricted stock units granted in period	$ 16.74
Weighted average grant date fair value of nonvested restricted stock units vested in period	$ 10.13
Weighted average grant date fair value of nonvested restricted stock units vested in period	$ 11.76
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Weighted Average Contractual Term [Abstract]
Weighted average remaining contractual terms of nonvested restricted stock units	1 year 8 months 1 day
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Aggregate Intrinsic Value [Abstract]
Aggregate intrinsic value of nonvested restricted stock units	$ 68,453

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- Definition

The intrinsic value of nonvested awards on equity-based plans excluding option plans 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, as calculated by applying the disclosed pricing methodolgy.

+ References

No definition available.

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- Definition

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

+ References

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- Definition

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.

+ References

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- Definition

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).

+ References

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- Definition

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).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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- Definition

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.

+ References

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

-Publisher FASB

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- Definition

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.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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- Definition

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.

+ References

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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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- Definition

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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