Note 2 - Segment Information (Details) - Net Sales Based on the Geographic Location of the External Customer (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2014	Mar. 31, 2013
Note 2 - Segment Information (Details) - Net Sales Based on the Geographic Location of the External Customer [Line Items]
Net sales	$ 4,981	$ 4,507	$ 3,968	$ 3,652	$ 4,200	$ 3,952	$ 3,739	$ 3,396	$ 17,108	$ 15,287
Geographic Concentration Risk [Member] | UNITED STATES | Sales Revenue, Net [Member]
Note 2 - Segment Information (Details) - Net Sales Based on the Geographic Location of the External Customer [Line Items]
Net sales									11,435	10,296
Percentage of net sales									67.00%	67.00%
Geographic Concentration Risk [Member] | Europe [Member] | Sales Revenue, Net [Member]
Note 2 - Segment Information (Details) - Net Sales Based on the Geographic Location of the External Customer [Line Items]
Net sales									4,642	3,527
Percentage of net sales									27.00%	23.00%
Geographic Concentration Risk [Member] | Asia and Australia [Member] | Sales Revenue, Net [Member]
Note 2 - Segment Information (Details) - Net Sales Based on the Geographic Location of the External Customer [Line Items]
Net sales									349	345
Percentage of net sales									2.00%	2.00%
Geographic Concentration Risk [Member] | CANADA | Sales Revenue, Net [Member]
Note 2 - Segment Information (Details) - Net Sales Based on the Geographic Location of the External Customer [Line Items]
Net sales									274	471
Percentage of net sales									2.00%	3.00%
Geographic Concentration Risk [Member] | Middle East and Africa [Member] | Sales Revenue, Net [Member]
Note 2 - Segment Information (Details) - Net Sales Based on the Geographic Location of the External Customer [Line Items]
Net sales									254	468
Percentage of net sales									1.00%	3.00%
Geographic Concentration Risk [Member] | Latin America [Member] | Sales Revenue, Net [Member]
Note 2 - Segment Information (Details) - Net Sales Based on the Geographic Location of the External Customer [Line Items]
Net sales									154	180
Percentage of net sales									1.00%	2.00%
Geographic Concentration Risk [Member] | Sales Revenue, Net [Member]
Note 2 - Segment Information (Details) - Net Sales Based on the Geographic Location of the External Customer [Line Items]
Net sales									$ 17,108	$ 15,287
Percentage of net sales									100.00%	100.00%