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Note 15 - Share Capital (Details Textual) - USD ($) $ / shares in Units, $ in Millions |  |  |  | 6 Months Ended | 12 Months Ended
--- | --- | --- | --- | --- | ---
Jul. 16, 2020 | Jun. 10, 2019 | Jun. 06, 2018 | Jan. 31, 2021 | Jan. 31, 2021 | Jan. 31, 2020 | Jan. 31, 2019
Shares Issued, Price Per Share (in dollars per share) |  | $ 35.50 |  |  |  |  |
Stock Issued During Period, Shares, New Issues (in shares) |  | 6,900,000 |  |  |  | 6,900,000 |
Over-Allotment Option |  | 15.00% |  |  |  |  |
Stock Issued During Period, Value, New Issues |  | $ 245.0 |  |  |  |  |
Proceeds from Issuance of Common Stock, Net |  | $ 236.6 |  |  |  |  |
Proceeds from Stock Options Exercised |  |  |  |  | $ 6.2 | $ 1.5 | $ 0.5
Shelf Prospectus [Member] |  |  |  |  |  |  |
Shelf Prospectus Period (Month) |  |  | 2 years 30 days |  |  |  |
Shelf Prospectus, Maximum Amount |  |  | $ 750.0 |  |  |  |
The 2020 Base Shelf Prospectus [Member] |  |  |  |  |  |  |
Shelf Prospectus Period (Month) | 2 years 30 days |  |  |  |  |  |
Shelf Prospectus, Maximum Amount | $ 1,000.0 |  |  |  |  |  |
Stock Issued During Period, Shares, New Issues (in shares) |  |  |  | 0 |  |  |

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