Derivative Instruments (Details) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
FFAs | Other current assets
Derivative Instruments, Gain (Loss) [Line Items]
Collateral related to derivative instruments under collateral security arrangements	$ 1,700,000		$ 800,000
Bunker Swaps | Derivatives not designated as hedging instruments | Other current assets
Derivative Instruments, Gain (Loss) [Line Items]
Derivative liability	0		(929,313)
Level 2 | Derivatives not designated as hedging instruments
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives not designated as hedging instruments, location of (gain)/loss recognized	(2,438,255)	$ 100,379
Level 2 | FFAs | Derivatives not designated as hedging instruments | Other current assets
Derivative Instruments, Gain (Loss) [Line Items]
Derivative asset	2,400,435		669,240
Level 2 | FFAs | Other (income)/expense | Derivatives not designated as hedging instruments
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives not designated as hedging instruments, location of (gain)/loss recognized	(1,170,288)	54,934
Level 2 | Bunker Swaps | Derivatives not designated as hedging instruments | Other current assets
Derivative Instruments, Gain (Loss) [Line Items]
Derivative asset	297,646		$ 0
Level 2 | Bunker Swaps | Other (income)/expense | Derivatives not designated as hedging instruments
Derivative Instruments, Gain (Loss) [Line Items]
Derivatives not designated as hedging instruments, location of (gain)/loss recognized	$ (1,267,967)	$ 45,445