Income per share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Income per share (Details)
Net income	$ 402	$ 6,563	$ 3,194	$ 10,048
Weighted average basic shares outstanding	1,761	1,760	1,761	1,761
Add: Effect of dilutive securities	2,000	1,000	1,000	1,000
Weighted average diluted shares outstanding	1,763	1,761	1,762	1,762
Basic	$ 0.23	$ 3.73	$ 1.81	$ 5.71
Diluted	$ 0.23	$ 3.73	$ 1.81	$ 5.70