Note 7 - Commitments and Contingencies (Details Textual)	1 Months Ended	3 Months Ended	12 Months Ended
	Feb. 28, 2002	Jun. 30, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)	Aug. 31, 2014 ft²
Inventories [Member] | Scenario, Forecast [Member]
Long-term Purchase Commitment, Expected Payment		$ 300,000
Inventories [Member]
Purchase Commitment, Amount Executed			$ 1,900,000
Royalty Payment, Percentage of Net Sales	2.50%
Area of Real Estate Property | ft²						5,000
Operating Leases, Rent Expense			200,000	$ 200,000	$ 200,000
Security Deposit			14,000
Letters of Credit Outstanding, Amount			14,000	38,000
Loans Pledged as Collateral			$ 14,000	$ 39,000