(5) Marketable Securities (Details) (USD $)	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Aggregate Fair Value	$ 7,838,590	$ 10,530,942
Cost or Amortized Cost	7,833,830	10,524,732
Net Unrealized Gains / (loss)	4,760	6,210
Government Securities Member
Aggregate Fair Value	7,838,590	8,328,392
Cost or Amortized Cost	7,833,830	8,324,372
Net Unrealized Gains / (loss)	4,760	4,020
Corporate Debt Securities Member
Aggregate Fair Value	0	2,202,550
Cost or Amortized Cost	0	2,200,360
Net Unrealized Gains / (loss)	$ 0	$ 2,190