Note 6 - Stock Incentive Plan Activities (Details) - $ / shares shares in Thousands	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Awards Available (in shares)	2,362	1,082	2,815
Options Outstanding (in shares)	9,605	8,986	8,073
Weighted Average Exercise Price (in dollars per share)			$ 6.09
Restricted stock awards granted (in shares)	(163)	(593)	(310)
Restricted stock awards cancelled (in shares)	1		53
Stock option awards granted (in shares)	(2,217)	(1,965)	(3,277)
Stock option awards granted (in shares)	2,217	1,965	3,277
Stock option awards granted (in dollars per share)	$ 11.52	$ 10.99	$ 3.05
Stock option awards exercised (in shares)	(1,118)	(1,258)	(563)
Stock option awards exercised (in dollars per share)	$ 4.36	$ 4.78	$ 2.37
Stock option awards cancelled (in shares)	33	88	1,801
Stock option awards cancelled (in shares)	(33)	(88)	(1,801)
Stock option awards cancelled (in dollars per share)	$ 9.87	$ 8.83	$ 7.22
Awards Available (in shares)	16	2,362	1,082
Options Outstanding (in shares)	10,671	9,605	8,986
Weighted Average Exercise Price (in dollars per share)	$ 7.50	$ 6.21	$ 4.99
Plan amendment (in shares)		3,750

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Share based compensation arrangement by share based payment award options forfeitures in period awards available.

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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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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 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 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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For presentations that combine terminations, 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 or that expired.

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Weighted average price of options that were either forfeited or expired.

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

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

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

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Other than shares newly issued, the number of additional shares issued (for example, a stock split) or canceled (for example, to correct a share issuance), during the period under the plan.

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

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

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