Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies - Derivative Financial Instruments (Details)

v2.4.0.6
Summary of Significant Accounting Policies - Derivative Financial Instruments (Details) (Interest Rate Swap, USD $)
 12 Months Ended 1 Months Ended 12 Months Ended 1 Months Ended 1 Months Ended
Dec. 31, 2007
contract
Dec. 31, 2007
Interest Rate Swap Contract 1
Dec. 31, 2007
Interest Rate Swap Contract 2
Mar. 31, 2010
Interest Rate Swap Contract 3
Swap
Jul. 31, 2011
Interest Rate Swap Contract 4
Swap
Dec. 31, 2012
Interest Rate Swap Contract 4
Dec. 31, 2011
Interest Rate Swap Contract 4
Dec. 31, 2010
Interest Rate Swap Contract 4
Oct. 31, 2012
Interest Rate Swap Contract 5
Swap
Dec. 31, 2012
Interest Rate Swap Contract 5
Oct. 31, 2012
Interest Rate Swap Contract 6
Swap
Derivative [Line Items]                      
Number of instruments 2     1 1       2   2
Initial notional amount of interest rate swaps   $ 13,080,607 $ 3,256,395 $ 27,900,000 $ 38,571,429       $ 16,750,000   $ 25,377,063
Interest rate swaps, variable to fixed interest rates   5.40% 5.30% 6.99% 1.965%       1.71%   3.70%
Future Increase in Notional Amount                   42,247,327  
Term of interest rate swap contract 15 years     14 years 5 years       8 years   8 years
Unrealized loss on cash flow derivative           $ 98,027 $ 1,313,587 $ 1,346,041