Note 17 - Business Segment Information (Detail) - Revenues and Accounts Receivable by Major Customers (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Sales	$ 1,547,000	$ 5,226,000
Accounts receivable	1,498,000	333,000
Alsher Titania LLC [Member] | Power And Energy Group [Member]
Sales	240,000
Accounts receivable	60,000
Gen-X [Member] | Power And Energy Group [Member]
Sales	217,000
Emrol [Member] | Power And Energy Group [Member]
Sales	200,000
TSK Solar [Member] | Power And Energy Group [Member]
Accounts receivable	686,000
HNEI [Member] | Power And Energy Group [Member]
Accounts receivable	352,000
Proterra, LLC [Member] | Power And Energy Group [Member]
Sales		2,109,000
Yintong Energy (YTE) [Member] | Power And Energy Group [Member]
Sales		1,794,000	[1]
Accounts receivable			[1]
Power And Energy Group [Member]
Sales	$ 1,302,000	$ 4,503,000

[1] YTE (an affiliate of Canon) became a related party, as of July 21, 2011.