Note 7 - Stock-Based Compensation (Detail) - Summary of Outsanding Stock Options by Exercise Price Range (USD $)	12 Months Ended
Dec. 31, 2012
Options Outstanding (in Shares)	1,914,000
Options Outstanding Weighted- Average Remaining Contractual Life (years)	4 years 73 days
Options Outstanding Weighted- Average Exercise Price	$ 11.38
Options Exercisable (in Shares)	1,833,500
Options Exercisable Weighted- Average Exercise Price	$ 11.48
Exercise Price From $2.76 To $5.51 [Member] \| Minimum [Member]
Range of Exercise Prices	$ 2.76
Exercise Price From $2.76 To $5.51 [Member] \| Maximum [Member]
Range of Exercise Prices	$ 5.51
Exercise Price From $2.76 To $5.51 [Member]
Options Outstanding (in Shares)	479,000
Options Outstanding Weighted- Average Remaining Contractual Life (years)	3 years 146 days
Options Outstanding Weighted- Average Exercise Price	$ 4.36
Options Exercisable (in Shares)	479,000
Options Exercisable Weighted- Average Exercise Price	$ 4.36
Exercise Price From $5.52 To $11.03 [Member] \| Minimum [Member]
Range of Exercise Prices	$ 5.52
Exercise Price From $5.52 To $11.03 [Member] \| Maximum [Member]
Range of Exercise Prices	$ 11.03
Exercise Price From $5.52 To $11.03 [Member]
Options Outstanding (in Shares)	825,875
Options Outstanding Weighted- Average Remaining Contractual Life (years)	5 years
Options Outstanding Weighted- Average Exercise Price	$ 8.88
Options Exercisable (in Shares)	745,375
Options Exercisable Weighted- Average Exercise Price	$ 8.85
Exercise Price From $11.04 To $22.06 [Member] \| Minimum [Member]
Range of Exercise Prices	$ 11.04
Exercise Price From $11.04 To $22.06 [Member] \| Maximum [Member]
Range of Exercise Prices	$ 22.06
Exercise Price From $11.04 To $22.06 [Member]
Options Outstanding (in Shares)	272,250
Options Outstanding Weighted- Average Remaining Contractual Life (years)	3 years 73 days
Options Outstanding Weighted- Average Exercise Price	$ 14.63
Options Exercisable (in Shares)	272,250
Options Exercisable Weighted- Average Exercise Price	$ 14.63
Exercise Price From $22.07 To $27.57 [Member] \| Minimum [Member]
Range of Exercise Prices	$ 22.07
Exercise Price From $22.07 To $27.57 [Member] \| Maximum [Member]
Range of Exercise Prices	$ 27.57
Exercise Price From $22.07 To $27.57 [Member]
Options Outstanding (in Shares)	336,875
Options Outstanding Weighted- Average Remaining Contractual Life (years)	4 years 36 days
Options Outstanding Weighted- Average Exercise Price	$ 24.86
Options Exercisable (in Shares)	336,875
Options Exercisable Weighted- Average Exercise Price	$ 24.86
Minimum [Member]
Range of Exercise Prices	$ 2.76
Maximum [Member]
Range of Exercise Prices	$ 27.57

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

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- Definition

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 Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph 64

-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.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (g)

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- Definition

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 Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(1)(c)

-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.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(iii)

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- Definition

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

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)(i)-(ii)

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

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-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

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-Subparagraph b(1)(a, b)

-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.

+ Details

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- Definition

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

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- Definition

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

+ Details

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