Note 12 - Segment Information (Detail) - Total Assets By Segment (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011
Cash and Marketable Securities:
Cash and cash equivalents	$ 6,482	$ 7,381	$ 4,786	$ 4,970
Marketable securities	11,361	13,504
Total Cash and Marketable Securities	17,843	20,885
Power supplies and Storage	7,671	7,939
Total assets	25,514	28,824
Power Supplies [Member]
Cash and Marketable Securities:
Power supplies and Storage	775	2,142
Storage [Member]
Cash and Marketable Securities:
Power supplies and Storage	$ 6,896	$ 5,797