Note 3 - Revenues 2 (Details Textual) - Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-07-01 $ in Millions	Jun. 30, 2019 USD ($)
Revenue, Remaining Performance Obligation, Amount	$ 436
Revenue, Remaining Performance Obligation, Percentage	90.70%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 years