Note 7 - Revenue 2 (Details Textual) - Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-10-01 $ in Millions	Sep. 30, 2020 USD ($)
Fixed-price Contract [Member]
Revenue, Remaining Performance Obligation, Amount	$ 494
Revenue, Remaining Performance Obligation, Percentage	57.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period (Year)	1 year
Contracts with Price Reopeners [Member]
Revenue, Remaining Performance Obligation, Amount	$ 237
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period (Year)	2022 years