Note 6 - Leases (Details Textual) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
	Jan. 01, 2019	Jun. 30, 2019		Jun. 30, 2019		Mar. 31, 2019	Dec. 31, 2018
Operating Lease, Right-of-Use Asset		$ 2,688		$ 2,688			$ 0
Operating Lease, Liability, Total		1,990		1,990
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	$ 2,200	317	[1]	2,581	[1]
Operating Lease, Lease Income, Lease Payments		$ 700		$ 900
Maximum [Member]
Lessee, Operating Lease, Term of Contract						4 years
Lessee, Operating Lease, Renewal Term		5 years		5 years
Lessor, Operating Lease, Term of Contract		5 years		5 years
Lessor, Operating Lease, Renewal Term		5 years		5 years

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