Commitments and Contingencies - Additional Information (Details)		1 Months Ended			3 Months Ended			6 Months Ended
	Jun. 29, 2020 USD ($)	Jan. 31, 2020 USD ($)	Sep. 30, 2019 USD ($)	Feb. 28, 2019 USD ($)	Jun. 30, 2020 USD ($) vessel	Jun. 30, 2019 USD ($)	Mar. 31, 2019	Jun. 30, 2020 USD ($) vessel	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Dec. 31, 2019 USD ($) contract vessel
Commitments and Contingencies [Line Items]
Payment for purchase of vessels								$ 1,652,366		$ 25,557,060
Investment in newbuildings in-process			$ 15,390,634		$ 15,400,000			$ 15,400,000	$ 15,390,634		$ 15,357,189
Number of dry bulk vessels financed under finance leases | vessel					3			3			4
Sale of vessel, selling price									$ 32,000,000
Sale price at fair market value at closing, percentage			0.85						0.85
Vessel charter period obligation									15 years
Purchase obligation			$ 2,500,000						$ 2,500,000
Time charter, term to completion								70 days	15 years
Noncancelable period							6 months
Lease expense					$ 52,000	$ 52,000		$ 104,000		$ 104,000
m/v Bulk Destiny
Commitments and Contingencies [Line Items]
Proceeds from financing revenue received under leases								21,000,000.0
Finance lease, right-of-use assets					24,000,000.0			$ 24,000,000.0
Useful life								25 years
Periodic payment terms, balloon payment to be paid					$ 11,200,000			$ 11,200,000
Basis spread on variable rate								2.75%
Interest rate, effective percentage					4.12%			4.12%
Term of contract					7 years			7 years
m/v Bulk Beothuk
Commitments and Contingencies [Line Items]
Finance lease, right-of-use assets					$ 7,000,000.0			$ 7,000,000.0
Periodic payment terms, balloon payment to be paid					$ 4,000,000.0			$ 4,000,000.0
Interest rate, stated percentage					11.83%			11.83%
Repayments lease obligation		$ 5,500,000
Proceeds from sale of vessels	$ 4,600,000
Loss on impairment of vessels					$ 1,800,000
Term of contract					5 years			5 years
Lease Payable					$ 3,500			$ 3,500
m/v Bulk Trident
Commitments and Contingencies [Line Items]
Proceeds from financing revenue received under leases								$ 13,000,000.0
Basis spread on variable rate								1.70%
Interest rate, effective percentage					2.06%			2.06%
Term of contract					8 years			8 years
m/v Bulk PODS
Commitments and Contingencies [Line Items]
Proceeds from financing revenue received under leases								$ 14,800,000
Interest rate, effective percentage					2.00%			2.00%
Term of contract					8 years			8 years
m/v Bulk Spirit
Commitments and Contingencies [Line Items]
Periodic payment terms, balloon payment to be paid				$ 3,900,000
Term of contract				8 years
Payment for purchase of vessels				$ 13,000,000.0
Interest for first five years				5.10%
Introductory period				5 years
Remainder of lease term after introductory period				3 years
m/v BULK FRIENDSHIP
Commitments and Contingencies [Line Items]
Payment for purchase of vessels			$ 14,100,000
Interest for first five years					5.29%			5.29%
Purchase options, vessel					$ 7,800,000			$ 7,800,000
dwt Dry Bulk
Commitments and Contingencies [Line Items]
Number of vessel newbuilding contracts | contract											2
Number of vessels | vessel					4			4			4
Percentage of payment, second installment due					0.20			0.20
Singapore
Commitments and Contingencies [Line Items]
Lease payable					14 months			14 months
Minimum | dwt Dry Bulk
Commitments and Contingencies [Line Items]
Payment for purchase of vessels									$ 37,700,000
Maximum | dwt Dry Bulk
Commitments and Contingencies [Line Items]
Payment for purchase of vessels									$ 38,300,000