Note 10 - Leases (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
Operating Leases, Rent Expense, Net, Total		$ 10,739	$ 10,845
Accounting Standards Update 2016-02 [Member]
Operating Lease, Right-of-Use Asset				$ 42,024
Operating Lease, Liability, Total				42,056
Cumulative Effect of New Accounting Principle in Period of Adoption				$ 0
Maximum [Member]
Lessee, Operating Lease and Finance Lease, Remaining Term of Contract	20 years
Lessee, Operating Lease, Renewal Term	10 years