Short-term Investments (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	$ 27,084,980	$ 24,000,000
Certificates of Deposit [Member] | Maturity date of April 24, 2014 [Member]
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	10,000,000
Certificates of Deposit [Member] | Maturity date of May 1, 2014 [Member]
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	12,100,000
Certificates of Deposit [Member] | Maturity date of October 30, 2014 [Member]
Schedule of Available-for-sale Securities [Line Items]
Short-term investments	$ 5,000,000