Debt (Details 7) (USD $)
Jun. 30, 2013
Dec. 31, 2012
Dec. 31, 2011
Debt issue costs $ 335,433 $ 851,923 $ 305,283
Accumulated amortization of debt issue costs (335,433) (516,490) (237,095)
Debt issue costs - net $ 0 $ 335,433 $ 68,188