Derivatives and Hedging Activities - Fair Value of Derivatives and Balance Sheet Classification (Details) - Designated as hedging instrument - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Asset Derivatives	$ 817,504	$ 739,606
Liability Derivatives	(4,512,878)	(3,067,572)
Interest rate products | Other assets - current
Derivatives, Fair Value [Line Items]
Asset Derivatives	108,877	243
Interest rate products | Other assets - non-current
Derivatives, Fair Value [Line Items]
Asset Derivatives	205,468	84,058
Interest rate products | Other liabilities - current
Derivatives, Fair Value [Line Items]
Liability Derivatives	0	(71,915)
Cross currency contract | Other assets - current
Derivatives, Fair Value [Line Items]
Asset Derivatives	503,159	655,305
Cross currency contract | Long-term derivative liability
Derivatives, Fair Value [Line Items]
Liability Derivatives	$ (4,512,878)	$ (2,995,657)