Note 10 - Leases (Details Textual) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2018
Operating Lease, Weighted Average Discount Rate, Percent	3.14%	3.14%
Operating Lease, Weighted Average Remaining Lease Term	5 years 5 months 19 days	5 years 5 months 19 days
Operating Lease, Right-of-Use Asset	$ 34,518	$ 34,518	$ 0
Operating Lease, Right-of-use Asset, Accumulated Amortization	6,200	6,200
Operating Lease, Expense	3,300	10,100
Operating Lease, Payments	$ 2,100	$ 6,200