Short-term Investments (Details) - USD ($)	Dec. 31, 2015	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	$ 35,035,420	$ 45,621,593
Certificates of Deposit [Member] | Maturity date of February 26, 2016 [Member]
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	15,000,000
Certificates of Deposit [Member] | Maturity date of March 31, 2016 [Member]
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	$ 20,000,000