Note 3 - Revenue From Contracts With Customers 2 (Details Textual) - Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2014-01-01	Mar. 31, 2019
Minimum [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	90 days
Maximum [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	270 days