Note 1 - Significant Accounting Policies 2 (Details Textual) - Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01	Dec. 31, 2019 USD ($)
Maintenance [Member]
Revenue, Remaining Performance Obligation, Amount	$ 2,104,000
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Service, Other [Member]
Revenue, Remaining Performance Obligation, Amount	$ 114,000
Service, Other [Member] | Minimum [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Service, Other [Member] | Maximum [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	3 years