Note 9 - Commitments and Contingencies (Detail) - Warranty Reserve (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Balance at beginning of year	$ 561	$ 764	$ 294
Warranty provision for product sales	917	870	801
Settlements made during the period	(675)	(626)	(107)
Unused warranty provision	(472)	(447)	(224)
Balance at end of period	$ 331	$ 561	$ 764