Note 9 - Share Capital	9 Months Ended
Sep. 30, 2020
Notes to Financial Statements
Stockholders' Equity Note Disclosure [Text Block]	9. Share capital During the nine-month period ended September 30, 2020, the Company issued 27,616 ordinary shares upon the exercise of options and 45,130 ordinary shares were issued upon the vesting of restricted share units, or RSUs. During the year ended December 31, 2019, the Company issued 394,078 ordinary shares upon the exercise of options and 65,405 ordinary shares were issued upon the vesting of RSUs. In 2019, the Company’s Board of Directors authorized the repurchase of up to $100 million of its ordinary shares in the aggregate (including commissions), subject to the approval of its shareholders by an ordinary resolution at its 2019 Annual General Meeting, or the share repurchase program. The share repurchase program was approved by the Company’s shareholders at its Annual General Meeting held on June 18, 2019. The Company began repurchasing shares in September 2019. For the four month period ended December 31, 2019, the Company purchased a total of 478,856 shares for a total cost of $7.0 million. During the three-month period ended March 31, 2020, the Company repurchased 530,890 ordinary shares at a total cost of $7.7 million. No shares were repurchased during the second or third quarters of 2020, as the share repurchase program has been paused. At September 30, 2020, $85.3 million of ordinary shares remain eligible for repurchase. The share repurchase program may be suspended, modified or terminated at any time. The Company has no obligation to repurchase any amount of its ordinary shares under the program. Unless terminated by the Company’s Board of Directors, the share repurchase program will be valid for up to five years from the date of inception of the program.

Note 9 - Share Capital

9 Months Ended

Sep. 30, 2020

Stockholders' Equity Note Disclosure [Text Block]

9. Share capital

During the nine-month period ended September 30, 2020, the Company issued 27,616 ordinary shares upon the exercise of options and 45,130 ordinary shares were issued upon the vesting of restricted share units, or RSUs. During the year ended December 31, 2019, the Company issued 394,078 ordinary shares upon the exercise of options and 65,405 ordinary shares were issued upon the vesting of RSUs.

In 2019, the Company’s Board of Directors authorized the repurchase of up to $100 million of its ordinary shares in the aggregate (including commissions), subject to the approval of its shareholders by an ordinary resolution at its 2019 Annual General Meeting, or the share repurchase program. The share repurchase program was approved by the Company’s shareholders at its Annual General Meeting held on June 18, 2019. The Company began repurchasing shares in September 2019. For the four month period ended December 31, 2019, the Company purchased a total of 478,856 shares for a total cost of $7.0 million. During the three-month period ended March 31, 2020, the Company repurchased 530,890 ordinary shares at a total cost of $7.7 million. No shares were repurchased during the second or third quarters of 2020, as the share repurchase program has been paused. At September 30, 2020, $85.3 million of ordinary shares remain eligible for repurchase. The share repurchase program may be suspended, modified or terminated at any time. The Company has no obligation to repurchase any amount of its ordinary shares under the program. Unless terminated by the Company’s Board of Directors, the share repurchase program will be valid for up to five years from the date of inception of the program.