Note 10 - Leases - Supplemental Balance Sheet Information Related to Leases (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019		Dec. 31, 2018
Operating ROU assets	$ 2,140	$ 2,308
Current operating lease liabilities699	697	699	[1]
Operating lease obligations, net of current portion	1,489	1,652	[1]
Total operating lease liabilities	2,186	$ 2,351
Property and equipment under finance lease, gross	45,887			44,730
Less accumulated amortization	(31,919)			(30,577)
Property and equipment under finance lease, net	13,968			14,153
Current obligations of finance leases	231			204
Noncurrent obligations of finance leases	617			676
Total finance lease liabilities	$ 848			$ 880
Operating leases (Year)	4 years 156 days
Finance leases (Year)	3 years 332 days
Operating leases	4.81%
Finance leases	4.94%
Furniture and Equipment Held under Finance Leases [Member]
Property and equipment under finance lease, gross	$ 1,062			$ 1,062
Computer Equipment Held under Finance Leases [Member]
Property and equipment under finance lease, gross	512			487
Computer Software Held under Finance Leases [Member]
Property and equipment under finance lease, gross	224			224
Assets Held under Finance Leases [Member]
Property and equipment under finance lease, gross	1,798			1,773
Less accumulated amortization	(901)			(839)
Property and equipment under finance lease, net	$ 897			$ 934

[1] Represents the December 31, 2018 balance recorded at implementation of Topic 842