Commitment and contingencies - Narrative (Details) $ in Millions	Dec. 31, 2023 USD ($) vessel
Commitments and Contingencies Disclosure [Abstract]
Number of vessels under construction \| vessel	6
Prepaid expense, number of vessels under construction \| vessel	2
Prepaid expense \| $	$ 4.8
Scrubbers cost payable, number of vessels under construction \| vessel	4
Scrubbers cost payable \| $	$ 9.6
Unrecorded unconditional purchase obligation, purchases financed by third party \| $	$ 295.5

Carrying amount as of the balance sheet date of expenditures made in advance of when the economic benefit of the cost will be realized, and which will be expensed in future periods with the passage of time or when a triggering event occurs.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 944
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(10))
-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 210
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.6-04(7)(a))
-Publisher FASB
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 210
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(7))
-Publisher FASB
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant