Note 3 - Revenue From Contracts With Customers (Details Textual) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Contract with Customer, Payment Term, Minimum (Day)	15 days
Contract with Customer, Payment Term, Maximum (Day)	90 days
Contract with Customer, Transaction Price of Royalties Using Expected Value Method	$ 0
Revenue from Contract with Customer, Including Assessed Tax	15,000	$ 14,000
Contract with Customer, Asset, Impairment Loss	0	$ 0
Capitalized Contract Cost, Net, Total	0
Contract with Customer, Asset, after Allowance for Credit Loss, Total	$ 0		$ 0
INDIA
Contract with Customer, Term of Contract (Year)	8 years
CHINA
Contract with Customer, Term of Contract (Year)	10 years