Note 13 - Equity Incentive Plans and Employee Benefits (Details) - Stock Options by Exercise Prices Range (USD $)	12 Months Ended
Jan. 31, 2015
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number outstanding (in Shares)	3,768,058
Weighted average remaining contractual term	4 years 350 days
Weighted average exercise price	$ 10.86
Number exercisable (in Shares)	2,889,268
Weighted average exercise price	$ 12.55
Range One [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices - lower	$ 0.92
Range of exercise prices - upper	$ 4.59
Number outstanding (in Shares)	532,337
Weighted average remaining contractual term	8 years 229 days
Weighted average exercise price	$ 4.43
Number exercisable (in Shares)	123,959
Weighted average exercise price	$ 4.41
Range Two [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices - lower	$ 4.63
Range of exercise prices - upper	$ 6.48
Number outstanding (in Shares)	405,323
Weighted average remaining contractual term	8 years 138 days
Weighted average exercise price	$ 5.35
Number exercisable (in Shares)	141,346
Weighted average exercise price	$ 5.73
Range Three [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices - lower	$ 6.49
Range of exercise prices - upper	$ 9.40
Number outstanding (in Shares)	388,031
Weighted average remaining contractual term	7 years 21 days
Weighted average exercise price	$ 7.00
Number exercisable (in Shares)	212,007
Weighted average exercise price	$ 7.40
Range Four [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices - lower	$ 9.45
Range of exercise prices - upper	$ 10.59
Number outstanding (in Shares)	402,028
Weighted average remaining contractual term	4 years 233 days
Weighted average exercise price	$ 10.52
Number exercisable (in Shares)	400,758
Weighted average exercise price	$ 10.52
Range Five [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices - lower	$ 10.87
Range of exercise prices - upper	$ 11.06
Number outstanding (in Shares)	692,230
Weighted average remaining contractual term	2 years 222 days
Weighted average exercise price	$ 10.97
Number exercisable (in Shares)	692,230
Weighted average exercise price	$ 10.97
Range Six [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices - lower	$ 11.07
Range of exercise prices - upper	$ 11.09
Number outstanding (in Shares)	482,314
Weighted average remaining contractual term	3 years 6 months
Weighted average exercise price	$ 11.08
Number exercisable (in Shares)	478,555
Weighted average exercise price	$ 11.08
Range Seven [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices - lower	$ 11.40
Range of exercise prices - upper	$ 12.39
Number outstanding (in Shares)	381,497
Weighted average remaining contractual term	3 years 87 days
Weighted average exercise price	$ 11.69
Number exercisable (in Shares)	359,767
Weighted average exercise price	$ 11.68
Range Eight [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices - lower	$ 13.58
Range of exercise prices - upper	$ 31.57
Number outstanding (in Shares)	336,298
Weighted average remaining contractual term	2 years 270 days
Weighted average exercise price	$ 16.96
Number exercisable (in Shares)	332,646
Weighted average exercise price	$ 16.99
Range Nine [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices - lower	$ 41.58
Range of exercise prices - upper	$ 41.58
Number outstanding (in Shares)	100,000
Weighted average remaining contractual term	3 years 10 days
Weighted average exercise price	$ 41.58
Number exercisable (in Shares)	100,000
Weighted average exercise price	$ 41.58
Range Ten [Member]
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices - lower	$ 45.83
Range of exercise prices - upper	$ 45.83
Number outstanding (in Shares)	48,000
Weighted average remaining contractual term	2 years 277 days
Weighted average exercise price	$ 45.83
Number exercisable (in Shares)	48,000
Weighted average exercise price	$ 45.83

Weighted average exercise price as of the balance sheet date for those equity-based payment arrangements exercisable and outstanding.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)(iii)

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The floor of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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-SubTopic 10

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The number of shares reserved for issuance pertaining to the outstanding exercisable stock options as of the balance sheet date in the customized range of exercise prices for which the market and performance vesting condition has been satisfied.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

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

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The number of shares reserved for issuance pertaining to the outstanding stock options as of the balance sheet date for all option plans in the customized range of exercise prices.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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The weighted average price as of the balance sheet date at which grantees could acquire the underlying shares with respect to all outstanding stock options which are in the customized range of exercise prices.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

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

+ References

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

-Publisher FASB

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The ceiling of a customized range of exercise prices for purposes of disclosing shares potentially issuable under outstanding stock option awards on all stock option plans and other required information pertaining to awards in the customized range.

+ References

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

-Publisher FASB

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