Marketable Securities and Fair Value Measurements (Details) (USD $)	Sep. 30, 2012	Dec. 31, 2011
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, Fair Value	$ 21,471,028	$ 38,365,818
Liabilities, Fair Value	6,162,948	5,176,319
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	10,395,462	25,402,398
Liabilities, Fair Value
Using Significant Other Unobservable Inputs (Level 2) [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, Fair Value	10,554,966	12,863,420
Liabilities, Fair Value
Using Significant Unobservable Inputs (Level 3) [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, Fair Value	520,600	100,000
Liabilities, Fair Value	6,162,948	5,176,319
Money market funds [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, Fair Value	2,141,745	16,330,885
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	2,141,745	16,330,885
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
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
Mutual funds [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, Fair Value	6,101,043	6,037,115
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
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	6,101,043	6,037,115
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
Certificates of deposit [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, Fair Value	2,749,668	5,768,304
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
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	2,749,668	5,768,304
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
Municipal bonds [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, Fair Value	1,704,255	1,058,001
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
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	1,704,255	1,058,001
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
Investment in affiliated entity [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, Fair Value	8,253,717	9,071,513
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	8,253,717	9,071,513
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
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
Common stock warrants [Member]
Financial assets and liabilities that are measured at fair value on recurring basis
Assets, Fair Value	520,600	100,000
Liabilities, Fair Value	6,162,948	5,176,319
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
Liabilities, Fair Value
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
Liabilities, Fair Value
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	520,600	100,000
Liabilities, Fair Value	$ 6,162,948	$ 5,176,319