Note 8 - Property and Equipment and Leases - Schedule of Equipment (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2021
Dec. 31, 2020
Statement Line Items [Line Items]    
Balance, Property and equipment and leases $ 1,448 $ 1,374
Additions   74
Additions and remeasurements 0  
Balance, Property and equipment and leases 1,448 1,448
Balance, Accumulated depreciation 773 593
Amortization, Property and equipment and leases 191 180
Balance, Accumulated depreciation 964 773
Balance, Carrying amounts 484 675
Office and computer equipment [member]    
Statement Line Items [Line Items]    
Balance, Property and equipment and leases 487 483
Additions   4
Additions and remeasurements 2  
Balance, Property and equipment and leases 489 487
Balance, Accumulated depreciation 460 449
Amortization, Property and equipment and leases 8 11
Balance, Accumulated depreciation 468 460
Balance, Carrying amounts 21 27
Mining assets [member]    
Statement Line Items [Line Items]    
Balance, Property and equipment and leases 411 341
Additions   70
Additions and remeasurements 3  
Balance, Property and equipment and leases 414 411
Balance, Accumulated depreciation 111 52
Amortization, Property and equipment and leases 45 59
Balance, Accumulated depreciation 156 111
Balance, Carrying amounts 258 300
Right-of-use assets [member]    
Statement Line Items [Line Items]    
Balance, Property and equipment and leases 550 550
Additions   0
Additions and remeasurements (5)  
Balance, Property and equipment and leases 545 550
Balance, Accumulated depreciation 202 92
Amortization, Property and equipment and leases 138 110
Balance, Accumulated depreciation 340 202
Balance, Carrying amounts $ 205 $ 348