Marketable Securities and Fair Value Measurements (Details) (Fair Value, Measurements, Recurring [Member], USD $)	Jun. 30, 2013	Dec. 31, 2012
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value	$ 28,718,042	$ 20,690,939
Liabilities, fair value	13,453,937	2,859,899
Using Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value	15,344,763	12,389,738
Liabilities, fair value	0	0
Using Significant Other Unobservable Inputs (Level 2) [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value	13,107,779	8,034,001
Liabilities, fair value	0	0
Using Significant Unobservable Inputs (Level 3) [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value	265,500	267,200
Liabilities, fair value	13,453,937	2,859,899
Money market funds [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value	7,509,566	1,686,406
Money market funds [Member] \| Using Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value	7,509,566	1,686,406
Money market funds [Member] \| Using Significant Other Unobservable Inputs (Level 2) [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value		0
Money market funds [Member] \| Using Significant Unobservable Inputs (Level 3) [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value	0	0
Mutual funds [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value	13,107,779	7,583,931
Mutual funds [Member] \| Using Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value	0	0
Mutual funds [Member] \| Using Significant Other Unobservable Inputs (Level 2) [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value	13,107,779	7,583,931
Mutual funds [Member] \| Using Significant Unobservable Inputs (Level 3) [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value	0	0
Certificates of deposit [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value		250,000
Certificates of deposit [Member] \| Using Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value		0
Certificates of deposit [Member] \| Using Significant Other Unobservable Inputs (Level 2) [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value		250,000
Certificates of deposit [Member] \| Using Significant Unobservable Inputs (Level 3) [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value		0
Municipal bonds [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value		200,070
Municipal bonds [Member] \| Using Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value		0
Municipal bonds [Member] \| Using Significant Other Unobservable Inputs (Level 2) [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value		200,070
Municipal bonds [Member] \| Using Significant Unobservable Inputs (Level 3) [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value		0
Investment in affiliated entity [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value	7,835,197	10,703,332
Investment in affiliated entity [Member] \| Using Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value	7,835,197	10,703,332
Investment in affiliated entity [Member] \| Using Significant Other Unobservable Inputs (Level 2) [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value	0	0
Investment in affiliated entity [Member] \| Using Significant Unobservable Inputs (Level 3) [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value	0	0
Common stock warrants [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value	265,500	267,200
Liabilities, fair value	13,453,937	2,859,899
Common stock warrants [Member] \| Using Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value	0	0
Liabilities, fair value	0	0
Common stock warrants [Member] \| Using Significant Other Unobservable Inputs (Level 2) [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value	0	0
Liabilities, fair value	0	0
Common stock warrants [Member] \| Using Significant Unobservable Inputs (Level 3) [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, fair value	265,500	267,200
Liabilities, fair value	$ 13,453,937	$ 2,859,899