Note 10 - Leases - Undiscounted Payments Under Non-cancelable Leases (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Jan. 01, 2019		Dec. 31, 2018
Finance leases, remainder 2019	$ 200
Operating leases, remainder 2019	601
Finance leases, 2020	249
Operating leases, 2020	591
Finance leases, 2021	222
Operating leases, 2021	449
Finance leases, 2022	168
Operating leases, 2022	225
Finance leases, 2023	85
Operating leases, 2023	245
Finance leases, thereafter
Operating leases, thereafter	320
Finance leases, total minimum lease payments	924
Operating leases, total minimum lease payments	2,431
Finance leases, less: Amount representing interest	(76)
Operating leases, less: Amount representing interest	(245)
Present value of minimum finance lease payments	848			$ 880
Operating Lease, Liability, Total	2,186	$ 2,351
Finance leases, less: current maturities	(231)			(204)
Operating leases, less: current maturities	(697)	(699)	[1]
Finance leases obligations, net of current portion	617			$ 676
Operating lease obligations, net of current portion	$ 1,489	$ 1,652	[1]

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