Note 5 - Leases (Details Textual) - USD ($) $ in Thousands		3 Months Ended				9 Months Ended
	Jan. 01, 2019	Sep. 30, 2020		Sep. 30, 2019		Sep. 30, 2020		Sep. 30, 2019		Dec. 31, 2019
Operating Lease, Right-of-Use Asset		$ 3,629				$ 3,629				$ 2,863
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 2,200	0	[1]	$ 869	[1]	1,796	[1]	$ 3,450	[1]
Operating Lease, Lease Income, Lease Payments		500		$ 500		1,300		$ 1,300
Other Assets [Member]
Operating Lease, Right-of-Use Asset		3,600				3,600				2,900
Other Liabilities [Member]
Operating Lease, Liability, Total		$ 3,100				$ 3,100				$ 2,400
Maximum [Member]
Lessee, Operating Lease, Remaining Lease Term (Year)		5 years				5 years
Lessee, Operating Lease, Renewal Term (Year)		2 years				2 years
Lessor, Remaining Lease Term (Year)						5 years
Lessor, Operating Lease, Renewal Term (Year)		5 years				5 years
Minimum [Member]
Lessor, Remaining Lease Term (Year)						1 year

[1] For the nine months ended September 30, 2019, the amount includes $2.2 million for operating leases existing on January 1, 2019.