Vessels and Vessel Improvements - Narrative (Details) $ in Thousands	3 Months Ended			12 Months Ended
	Dec. 31, 2021 USD ($) vessel	Sep. 30, 2021 vessel shares	Jun. 30, 2021 USD ($) vessel shares	Dec. 31, 2022 USD ($) vessel	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($) vessel	Sep. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Mar. 31, 2021 USD ($) vessel shares
Property, Plant and Equipment [Line Items]
Number of vessels | vessel				53
Advances for vessel purchases	$ 0			$ 3,638	$ 0	$ 3,300
Gain on sale of vessel				9,308	3,966	(490)
Write off of unamortized drydock costs					300
Number of vessels purchased | vessel									4
Common stock issued upon conversion (in shares) | shares		541,898	541,898
Transfer from advances paid for vessel purchases				$ 3,638	0	3,250
Warrants Issued For Consideration
Property, Plant and Equipment [Line Items]
Warrants outstanding (in shares) | shares									541,898
Warrants and rights outstanding									$ 10,700
Ballast Water Treatment System
Property, Plant and Equipment [Line Items]
Number of vessels, installation complete | vessel				48
Transfer from advances paid for vessel purchases				$ 8,200
Advances paid for vessel installation				2,000
Vessels and Vessel Improvements
Property, Plant and Equipment [Line Items]
Transfer from advances paid for vessel purchases				0	3,250
Advances paid for vessel installation				8,794	$ 4,589
High-Specification Scrubber-Fitted Ultramax Bulkcarriers
Property, Plant and Equipment [Line Items]
Vessel purchase price			$ 42,200	24,300		$ 51,500	$ 27,500		$ 15,300
Number of vessels purchased | vessel			2
Number of vessels delivered | vessel	2	2
High-Specification Scrubber-Fitted Ultramax Bulkcarriers | Warrants Issued For Consideration
Property, Plant and Equipment [Line Items]
Warrants outstanding (in shares) | shares									212,315
Crown-58 Supramax Bulkcarriers
Property, Plant and Equipment [Line Items]
Vessel purchase price									$ 20,500
Number of vessels purchased | vessel									3
Number of vessels delivered | vessel		4	4
Crown-58 Supramax Bulkcarriers | Warrants Issued For Consideration
Property, Plant and Equipment [Line Items]
Warrants outstanding (in shares) | shares									329,583
Vessel Tern
Property, Plant and Equipment [Line Items]
Vessel sold, consideration			$ 9,200
Vessel Cardinal
Property, Plant and Equipment [Line Items]
Vessel sold, consideration								$ 15,800
Gain on sale of vessel				$ 9,300
High-Specification Scrubber-Fitted Ultramax Bulkcarriers 2015
Property, Plant and Equipment [Line Items]
Number of vessels purchased | vessel						2
High-Specification Scrubber-Fitted Ultramax Bulkcarriers 2016
Property, Plant and Equipment [Line Items]
Number of vessels purchased | vessel						1