Vessels - Additional Information (Details)	3 Months Ended			6 Months Ended	9 Months Ended
	Sep. 30, 2021 USD ($) vessel	Jun. 30, 2021 USD ($) vessel shares	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($) vessel	Sep. 30, 2021 USD ($) vessel	Sep. 30, 2020 USD ($)	Jun. 01, 2021 USD ($)	Mar. 31, 2021 USD ($) vessel shares	Dec. 31, 2020 USD ($) vessel	Sep. 30, 2018 USD ($) vessel
Property, Plant and Equipment [Line Items]
Number of vessels | vessel	52			52	52
Number of vessels acquired | vessel								4
Issuance of shares upon conversion of warrants (in shares) | shares		541,898
(Gain)/loss on sale of vessel	$ 3,962,093		$ (389,207)		$ 3,962,093	$ (389,207)
Amount of unamortized drydock cost options written off	300,000				300,000
Amount recorded in balance sheet					2,200,000	$ 0
Warrants Issued For Consideration
Property, Plant and Equipment [Line Items]
Warrant for common stock (in shares) | shares								541,898
Fair value of warrants issued as consideration for vessel purchases								$ 10,700,000
High-Specification Scrubber-Fitted Ultramax Bulkcarriers
Property, Plant and Equipment [Line Items]
Number of vessels acquired | vessel		2							3
Vessel purchase price	$ 22,200,000	$ 44,000,000		$ 22,200,000	$ 22,200,000			$ 15,300,000	$ 51,500,000
Number of vessels delivered | vessel	1
High-Specification Scrubber-Fitted Ultramax Bulkcarriers | Warrants Issued For Consideration
Property, Plant and Equipment [Line Items]
Warrant for common stock (in shares) | shares								212,315
Crown-58 Supramax Bulkcarriers
Property, Plant and Equipment [Line Items]
Number of vessels acquired | vessel								3
Vessel purchase price								$ 22,400,000
Number of vessels delivered | vessel				4
Crown-58 Supramax Bulkcarriers | Warrants Issued For Consideration
Property, Plant and Equipment [Line Items]
Warrant for common stock (in shares) | shares								329,583
Ballast Water Treatment System
Property, Plant and Equipment [Line Items]
Number of vessels | vessel										39
Projected project costs										$ 500,000
Number of vessels, installation completed | vessel	17			17	17
Amount recorded in balance sheet					$ 8,500,000
Scrubbers and BWTS reclassified					5,300,000
Vessel Tern
Property, Plant and Equipment [Line Items]
Total consideration for vessel purchase							$ 9,200,000
(Gain)/loss on sale of vessel	$ 4,000,000				$ 4,000,000