Recent Accounting Pronouncements - Time In Charter Contracts (Details)										9 Months Ended
	Sep. 06, 2021 $ / d	Jul. 08, 2021 $ / d	Jun. 28, 2021 $ / d	May 04, 2021 $ / d	Dec. 22, 2020 route t $ / d	Dec. 25, 2019 $ / d	Dec. 09, 2018 t $ / d	May 04, 2018 t $ / d	Apr. 28, 2017 t $ / d	Sep. 30, 2021 USD ($) contract t	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Lessee, Lease, Description [Line Items]
Number of contracts | contract										5
Dead weight tonnage of operating fleet | t										3,128,107
Fair value below contract value of time charters acquired | $														$ 1,800,000
Increase to lease modification right-of-use asset | $											$ 1,000,000		$ 4,500,000
Increase to lease modification liability | $											$ 1,000,000		$ 4,500,000
Operating lease right-of-use assets | $										$ 22,845,697		$ 7,540,871
Operating lease, liability | $										$ 22,838,928
Minimum
Lessee, Lease, Description [Line Items]
Operating lease, term of contract										30 days
Incremental borrowing rate										5.05%
Charters agreement term, extension option					11 months
Maximum
Lessee, Lease, Description [Line Items]
Operating lease, term of contract										1 year
Incremental borrowing rate										6.08%
Charters agreement term, extension option					13 months
2013 Built Japanese Vessel
Lessee, Lease, Description [Line Items]
Dead weight tonnage of operating fleet | t									61,400
Charters agreement term									4 years
Charters agreement term, extension option									2 years
Increase to lease liability and the corresponding right-of-use asset | $										$ 5,000,000
Discount rate		1.36%
2013 Built Japanese Vessel | First Four Years
Lessee, Lease, Description [Line Items]
Vessel hiring rate (in dollars per day) | $ / d									12,800
2013 Built Japanese Vessel | First Optional Year
Lessee, Lease, Description [Line Items]
Vessel hiring rate (in dollars per day) | $ / d		13,800							13,800
2013 Built Japanese Vessel | Second Optional Year
Lessee, Lease, Description [Line Items]
Vessel hiring rate (in dollars per day) | $ / d									14,300
2013 Built Ultramax Vessel
Lessee, Lease, Description [Line Items]
Dead weight tonnage of operating fleet | t								61,425
Charters agreement term								3 years
Charters agreement term, extension option								2 years
Increase to lease liability and the corresponding right-of-use asset | $										5,800,000
2013 Built Ultramax Vessel | First Optional Year
Lessee, Lease, Description [Line Items]
Vessel hiring rate (in dollars per day) | $ / d								13,750
2013 Built Ultramax Vessel | Second Optional Year
Lessee, Lease, Description [Line Items]
Vessel hiring rate (in dollars per day) | $ / d			13,750					14,750
Discount rate			1.34%
2013 Built Ultramax Vessel | First Three Years
Lessee, Lease, Description [Line Items]
Vessel hiring rate (in dollars per day) | $ / d								12,700
2016 Built Ultramax Vessel
Lessee, Lease, Description [Line Items]
Dead weight tonnage of operating fleet | t							62,487
Charters agreement term							2 years
2016 Built Ultramax Vessel | First Two Years
Lessee, Lease, Description [Line Items]
Vessel hiring rate (in dollars per day) | $ / d						11,600	14,250
2016 Built Ultramax Vessel | Third Year Option
Lessee, Lease, Description [Line Items]
Vessel hiring rate (in dollars per day) | $ / d							15,250
2016 Built Ultramax Vessel | Additional Year Option
Lessee, Lease, Description [Line Items]
Vessel hiring rate (in dollars per day) | $ / d				12,600
Increase to lease liability and the corresponding right-of-use asset | $										4,300,000
Discount rate				1.38%
2021 Built Ultramax Vessel
Lessee, Lease, Description [Line Items]
Dead weight tonnage of operating fleet | t					63,634
Charters agreement term					12 months
Charters agreement term, extension option					3 months
Discount rate				1.33%
Charter agreement term, initial period					15 months
Operating lease right-of-use assets | $										9,100,000
Operating lease, liability | $										$ 9,100,000
2021 Built Ultramax Vessel | Minimum
Lessee, Lease, Description [Line Items]
Charters agreement term	12 months
2021 Built Ultramax Vessel | Maximum
Lessee, Lease, Description [Line Items]
Charters agreement term	15 months
2021 Built Ultramax Vessel | Additional Year Option
Lessee, Lease, Description [Line Items]
Vessel hiring rate (in dollars per day) | $ / d	10,750
2021 Built Ultramax Vessel | Twelve Month Option
Lessee, Lease, Description [Line Items]
Vessel hiring rate (in dollars per day) | $ / d					5,900
Vessel hire rate (usd per day)					57.00%
Number of routes | route					10
2021 Built Ultramax Vessel | Three Month Option
Lessee, Lease, Description [Line Items]
Vessel hiring rate (in dollars per day) | $ / d					6,500
Shared scrubber benefit					50.00%
Chartered-in contracts greater than 12 months
Lessee, Lease, Description [Line Items]
Number of contracts | contract										4
Operating lease right-of-use assets | $										$ 20,712,287		$ 6,207,253
Operating lease, liability | $										$ 20,705,519