Note 2 - Summary of Significant Accounting Policies (Details Textual) - USD ($)
$ in Thousands |
12 Months Ended |
|
|
Dec. 31, 2021 |
Dec. 31, 2020 |
Dec. 27, 2021 |
Dec. 31, 2008 |
| Statement Line Items [Line Items] |
|
|
|
|
| Total provision for decommissioning, restoration and rehabilitation costs |
$ 409
|
$ 409
|
|
|
| Stock option awards [member] |
|
|
|
|
| Statement Line Items [Line Items] |
|
|
|
|
| Antidilutive securities excluded from computation of earnings per share, amount (in shares) |
813,887
|
|
|
|
| Performance share units [member] |
|
|
|
|
| Statement Line Items [Line Items] |
|
|
|
|
| Antidilutive securities excluded from computation of earnings per share, amount (in shares) |
247,752
|
|
|
|
| Deferred share units [member] |
|
|
|
|
| Statement Line Items [Line Items] |
|
|
|
|
| Antidilutive securities excluded from computation of earnings per share, amount (in shares) |
383,078
|
|
|
|
| Common share equivalents [member] |
|
|
|
|
| Statement Line Items [Line Items] |
|
|
|
|
| Antidilutive securities excluded from computation of earnings per share, amount (in shares) |
|
1,882,225
|
|
|
| Minera Juanicipio, S.A. de C.V. [member] |
|
|
|
|
| Statement Line Items [Line Items] |
|
|
|
|
| Equity method investment, ownership percentage |
44.00%
|
44.00%
|
44.00%
|
44.00%
|
| Total provision for decommissioning, restoration and rehabilitation costs |
$ 4,050
|
$ 1,450
|
|
|