7. INCOME TAXES (Details 4) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	May 31, 2013	May 31, 2012	May 31, 2011
Components of Unrecognized Tax Benefits
Unrecognized tax benefit, Beginning	$ 1,022	$ 1,093	$ 1,181
Decreases related to prior year tax positions	0	0	0
Decreases related to lapse of statute of limitations	(15)	(71)	(88)
Unrecognized tax benefit, Ending	$ 1,007	$ 1,022	$ 1,093