Note 7 - Leases (Details Textual) - USD ($) $ in Thousands		12 Months Ended
	Jan. 01, 2019	Dec. 31, 2019		Dec. 31, 2018	Dec. 31, 2017
Operating Lease, Right-of-Use Asset		$ 2,863		$ 0
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 2,300	3,667	[1]
Operating Leases, Rent Expense, Net, Total				$ 1,800	$ 1,500
Operating Lease, Lease Income, Lease Payments		1,800
Other Assets [Member]
Operating Lease, Right-of-Use Asset		2,900
Other Liabilities [Member]
Operating Lease, Liability, Total		$ 2,400
Maximum [Member]
Lessee, Operating Lease, Remaining Lease Term		4 years
Lessee, Operating Lease, Renewal Term		5 years
Lessor, Remaining Lease Term		5 years
Lessor, Operating Lease, Renewal Term		5 years
Minimum [Member]
Lessor, Remaining Lease Term		1 year

[1] The amount includes $2.3 million for operating leases existing on January 1, 2019.