Earnings per share - Schedule of Reconciliation Profit and Share Data Used in the Basic and Diluted Earnings per Share ("EPS") Computations (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Earnings per share
Profit for the year	$ 166,158	$ 92,040	$ 62,697
Basic earnings per share (in dollars per share)	$ 4.55	$ 2.54	$ 1.62
Diluted earnings per share (in dollars per share)	$ 4.55	$ 2.54	$ 1.62
Weighted average of common shares outstanding applicable to basic EPS (in shares)	36,481	36,304	38,796
Weighted average of common shares outstanding applicable to diluted EPS (in shares)	36,481	36,304	38,796