Note 7 - Leases - Future Commitments Under Long-Term Leases (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
2020	$ 277
2020	561
2020	838
2021	267
2021	447
2021	714
2022	226
2022	407
2022	633
2023	32
2023	256
2023	288
2024	16
2024	110
2024	126
Thereafter	435
Thereafter
Thereafter	435
Total lease payments, Finance Lease	1,253
Total lease payments, Operating Lease	1,781
Total lease payments	3,034
Less imputed interest, Finance Lease	338
Less imputed interest, Operating Lease	150
Less imputed interest	488
Total, Finance Lease	915	$ 924
Operating Lease, Liability, Total	1,631
Total	2,546
Less: current portion of obligations under leases, Finance Lease	239	236
Less: current portion of obligations under leases, Operating Lease	493
Less: current portion of obligations under leases	732
Long-term portion of obligations under leases, Finance Lease	676	688
Long-term portion of obligations under leases, Operating Lease	1,138
Long-term portion of obligations under leases	$ 1,814