Note 6 - Leases - Lease Expenses (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Operating lease cost	$ 5,501	$ 16,891
Short-term lease cost	8,125	20,846
Total lease cost	13,626	37,737
Operating cash flows – Operating leases	5,461	16,905
Operating leases	$ 3,150	$ 10,982