Note 4 - Leases, Right-to-use Assets and Related Liabilities - Future Minimum Payments Under Non-cancelable Operating Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
2021 (remaining)	$ (241)
2021 (remaining), financing leases	1,950
2022, operating lease	265
2022, financing leases	3,800
2023, operating lease	297
2023, financing leases	1,708
2024, operating lease	305
2024, financing leases	1,725
2025, operating lease	315
2025, financing leases	1,738
2026 and thereafter, operating lease	1,030
2026 and thereafter, financing leases	21,636
Total, operating lease	1,971
Total, financing leases	32,557
Less: Amounts representing present value discounts, operating lease	(374)
Less: Amounts representing present value discounts, financing leases	(10,232)
Total lease liabilities, operating lease	1,597
Total lease liabilities, financing leases	22,325
Operating lease liabilities (current)	0	$ 172
Less: current portion, financing leases	(2,727)	(10)
Operating lease liabilities (long-term)	1,732	0
Finance lease liabilities (long-term)	19,598	$ 162
Prepaid Expenses and Other Current Assets [Member]
Operating lease liabilities (current)	$ 135