Note 4 - Revenues 2 (Details Textual) - Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01	Dec. 31, 2019
Minimum [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Maximum [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	5 years