Note 8 - Leases (Details Textual) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
Operating Lease, Right-of-Use Asset	$ 21,953		$ 0
Operating Lease, Liability, Total	$ 22,390		$ 20,369
Operating Lease, Weighted Average Remaining Lease Term	6 years 2 months 12 days
Operating Lease, Weighted Average Discount Rate, Percent	5.30%
Minimum [Member]
Lessee, Operating Lease, Term of Contract	1 year
Maximum [Member]
Lessee, Operating Lease, Term of Contract	10 years
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset		$ 20,000
Operating Lease, Liability, Total		$ 20,000