Derivative financial instruments - Schedule of fair value of derivative instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Offsetting Liabilities [Line Items]
Interest rate swaps - cash flow hedges, current	$ 708	$ 1,401
Interest rate swaps - cash flow hedges, non current	509	2,999
Derivative liabilities	1,217	4,400
Interest rate swaps - cash flow hedges
Offsetting Liabilities [Line Items]
Interest rate swaps - cash flow hedges, current	708	1,401
Interest rate swaps - cash flow hedges, non current	$ 509	$ 2,999

Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled within one year or normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset, expected to be settled after one year or the normal operating cycle, if longer. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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