Vessels and Vessel Improvements - Schedule of Vessels and vessel improvements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Movement in Property, Plant and Equipment [Roll Forward]
Beginning balance	$ 908,076
Transfer from advances paid for vessel purchases	3,638	$ 0	$ 3,250
Depreciation expense	(200)	(300)	(300)
Ending balance	891,877	908,076
Vessels and Vessel Improvements
Movement in Property, Plant and Equipment [Roll Forward]
Beginning balance	908,076	810,714
Transfer from advances paid for vessel purchases	0	3,250
Purchase of vessels and vessel improvements	28,289	128,326
Fair value of warrants issued as consideration for vessel purchases	0	10,680
Sale of vessels	(5,592)	(4,886)
Purchase of scrubbers and BWTS	8,794	4,589
Depreciation expense	(47,690)	(44,597)
Ending balance	$ 891,877	$ 908,076	$ 810,714