2. STOCK-BASED COMPENSATION - Option Activity (Details 3) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
Feb. 29, 2016	Nov. 30, 2015	Aug. 31, 2015	Feb. 29, 2016
Number of Options Outstanding, Ending (in thousands)	3,286			3,286
Weighted Average Exercise Price Outstanding, Ending	$ 1.66			$ 1.66
Options exercisable shares, ending (in thousands)	2,339			2,339
Weighted Average Exercise Price for Options exercisable, ending	$ 1.47			$ 1.47
Aggregate Intrinsic Value for Options exercisable, ending	$ 293			$ 293
Stock Options
Available Shares, Beginning (in thousands)	1,700	967	845	845
Options granted (in thousands)	(11)	(82)	0
Options terminated (in thousands)	110	15	122
Additional shares reserved (in thousands)		800
Available Shares, Ending (in thousands)	1,799	1,700	967	1,799
Options Outstanding, Beginning (in thousands)	3,385	3,434	3,686	3,686
Options Granted (in thousands)	11	82	0
Options terminated (in thousands)	(110)	(15)	(122)
Options exercised (in thousands)	0	(116)	(130)
Number of Options Outstanding, Ending (in thousands)	3,286	3,385	3,434	3,286
Weighted Average Exercise Price Outstanding, Beginning	$ 1.67	$ 1.63	$ 1.66	$ 1.66
Weighted Average Exercise Price Granted	1.36	2.22	0.00
Weighted Average Exercise Price Terminated	2.19	1.61	2.04
Weighted Average Exercise Price Exercised	0.00	0.91	1.72
Weighted Average Exercise Price Outstanding, Ending	$ 1.66	$ 1.67	$ 1.63	$ 1.66
Aggregate Intrinsic Value, beginning balance	$ 1,643	$ 2,587	$ 2,946	$ 2,946
Aggregate Intrinsic Value, ending balance	$ 294	$ 1,643	$ 2,587	$ 294
Options fully vested and expected to vest, ending (in thousands)	3,220			3,220
Options exercisable shares, ending (in thousands)	2,339			2,339
Weighted Average Exercise Price for Options fully vested and expected to vest, ending	$ 1.66			$ 1.66
Weighted Average Exercise Price for Options exercisable, ending	$ 1.47			$ 1.47
Aggregate Intrinsic Value for Options fully vested and expected to vest, ending	$ 288			$ 288
Aggregate Intrinsic Value for Options exercisable, ending	$ 293			$ 293

Number of additional shares authorized for issuance under an established share-based compensation 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 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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Weighted average price of options that were either forfeited or expired.

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

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