Note 13 - Supplemental Cash Flow Information - Summary of Supplemental Non-cash Transaction and Nonmonetary Exchange Information (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Supplemental Non-cash Transactions:
Capital expenditures incurred but not paid at September 30	$ 5,591	$ 2,607
Property acquired under capital leases	1,078
Additions to ARO asset	$ 200	$ 150