Derivative Instruments and Fair Value Measurements - Narrative (Details)	3 Months Ended		12 Months Ended
	Dec. 31, 2016 USD ($)	Mar. 31, 2016 USD ($) vessel	Dec. 31, 2017 USD ($) vessel	Dec. 31, 2015 USD ($)
Property, Plant and Equipment [Line Items]
Vessels impaired | vessel		6	22
Impairment of assets to be sold	$ 122,860,600	$ 6,167,262		$ 50,872,734
Carrying value of assets to be sold	234,860,600			$ 76,332,734
FFAs | Other current assets
Property, Plant and Equipment [Line Items]
Cash collateral related to derivative instruments under its collateral security arrangements	$ 0		$ 178,836