Note 7 - Leases - Lessee Assets and Liabilities (Details) - USD ($) $ in Thousands  | 
Dec. 31, 2020  | 
Dec. 31, 2019  | 
|---|---|---|
| ROU assets (Note 7) | $ 11,509 | $ 7,936 | 
| Other Noncurrent Assets [Member] | ||
| ROU assets (Note 7) | 11,509 | 7,936 | 
| Accrued Liabilities [Member] | ||
| Accrued liabilities | 394 | 2,716 | 
| Other Noncurrent Liabilities [Member] | ||
| Other liabilities | 11,360 | 4,419 | 
| Accrued Liabilities and Other Noncurrent Liabilities [Member] | ||
| Total lease liability | $ 11,754 | $ 7,135 | 
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- Definition Present value of lessee's discounted obligation for lease payments from operating lease. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Present value of lessee's discounted obligation for lease payments from operating lease, classified as current. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Present value of lessee's discounted obligation for lease payments from operating lease, classified as noncurrent. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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- Definition Amount of lessee's right to use underlying asset under operating lease. Reference 1: http://www.xbrl.org/2003/role/disclosureRef 
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