Note 5 - Intangible Assets - Expected Future Amortization Expense (Details) $ in Thousands	Dec. 31, 2018 USD ($)
Expected amortization expense, 2019	$ 205
Expected amortization expense, 2020	205
Expected amortization expense, 2021	205
Expected amortization expense, 2022	205
Expected amortization expense, 2023	170
Customer Relationships [Member]
Expected amortization expense, 2019	125
Expected amortization expense, 2020	125
Expected amortization expense, 2021	125
Expected amortization expense, 2022	125
Expected amortization expense, 2023	104
Intellectual Property [Member]
Expected amortization expense, 2019	80
Expected amortization expense, 2020	80
Expected amortization expense, 2021	80
Expected amortization expense, 2022	80
Expected amortization expense, 2023	$ 66