Note 16 - Supplemental Cash Flow Information - Summary of Supplemental Non-cash Transaction and Nonmonetary Exchange Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Capital expenditures incurred but not paid at March 31	$ 2,215	$ 3,878
Dividends payable at March 31, 2020	4,852
Additions to ARO asset	$ 70	$ 7