Defined Contribution Plan (Details Textual) (USD $)
6 Months Ended 12 Months Ended
Jun. 30, 2013
Jun. 30, 2012
Dec. 31, 2012
Dec. 31, 2011
Noncash Contribution Expense   $ 17,000    
Defined Contribution Plan, Employer Discretionary Contribution Amount $ 28,530 $ 18,251 $ 42,800 $ 0