Income taxes - Schedule of income tax expense (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets
Net operating loss carryforwards	$ 13,677	$ 11,500
Disallowed interest expense carryforward	1,335	56
Asset retirement obligation	2,169	1,128
Other deductible temporary differences	495	32
Total deferred tax assets	17,676	12,716
Less: valuation allowance	0	0
Net deferred tax assets	17,676	12,716
Deferred tax liabilities
Property, plant and equipment	(88,870)	(60,269)
Unrealized derivatives	(2,795)	(2,196)
Total deferred tax liabilities	(91,665)	(62,465)
Net deferred tax liability	$ (73,989)	$ (49,749)

Amount of deferred tax liability attributable to taxable temporary differences.

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