Note 4 - Accrued Liabilities (Details) - Warranty Reserve Roll-Forward (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Warranty Reserve Roll-Forward [Abstract]
Balance at beginning of period	$ 334	$ 443	$ 331	$ 561
Warranty provision for product sales	130	583	349	802
Settlements made	(3)	(29)	(98)	(154)
Unused warranty provision	(78)	(138)	(199)	(350)
Balance at end of period	$ 383	$ 859	$ 383	$ 859