Note 8 - Accrued Liabilities - Accrued Liabilities (Details) - USD ($)	Mar. 31, 2020	Dec. 31, 2019
Payroll expenses and taxes payable	$ 148,000	$ 299,000
Commissions and bonuses payable and general accrued liabilities	616,000	621,000
Total accrued liabilities	$ 764,000	$ 920,000