Annual report pursuant to Section 13 and 15(d)

Summary of Significant Accounting Policies - Statement of Income Restatement (Details)

v2.4.0.6
Summary of Significant Accounting Policies - Statement of Income Restatement (Details) (USD $)
 3 Months Ended 12 Months Ended
Dec. 31, 2012
Sep. 30, 2012
Jun. 30, 2012
Mar. 31, 2012
Dec. 31, 2011
Sep. 30, 2011
Jun. 30, 2011
Mar. 31, 2011
Dec. 31, 2010
Sep. 30, 2010
Jun. 30, 2010
Mar. 31, 2010
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Statements of Income Data:                              
Operating income $ 6,264 $ 10,709 $ 8,259 $ 3,425 $ 12,616 $ 16,409 $ 13,358 $ 8,303 $ 12,503 $ 18,913 $ 12,014 $ 2,563 $ 28,657,002 $ 50,685,824 $ 45,992,297
Other expenses, net 216 1,313 1,413 1,108 1,748 2,696 1,431 631 (185) 2,751 2,371 1,356 4,050,116 6,505,719 6,292,996
Income before provision for income taxes 6,048 9,396 6,846 2,317 10,868 13,713 11,927 7,672 12,688 16,162 9,643 1,207 24,606,886 44,180,105 39,699,301
Income tax provision 954 2,684 2,027 582 2,425 2,690 3,537 2,115 3,805 4,862 3,089 429 6,246,753 10,767,172 12,185,635
Net income 5,094 6,712 4,819 1,735 8,443 11,023 8,390 5,557 8,883 11,300 6,554 778 18,360,133 33,412,933 27,513,666
Net income per share attributable to common shareholders:                              
Basic (in usd per share) $ 0.11 $ 0.15 $ 0.11 $ 0.04 $ 0.19 $ 0.26 $ 0.20 $ 0.13 $ 0.22 $ 0.33 $ 0.48 $ 0.06 $ 0.41 $ 0.78 $ 1.07
Diluted (in usd per share) $ 0.11 $ 0.15 $ 0.10 $ 0.04 $ 0.19 $ 0.24 $ 0.18 $ 0.12 $ 0.19 $ 0.26 $ 0.17 $ 0.02 $ 0.40 $ 0.75 $ 0.66
As Reported
                              
Statements of Income Data:                              
Operating income   10,709 8,259 3,425 12,616 16,409 13,358 8,303 12,503 18,913 12,014 2,563   50,685,824 45,992,297
Other expenses, net   1,254 1,063 1,338 1,943 1,360 989 900 998 2,010 1,217 856   5,192,132 5,080,546
Income before provision for income taxes   9,455 7,196 2,087 10,673 15,049 12,369 7,403 11,505 16,903 10,797 1,707   45,493,692 40,911,751
Income tax provision   2,684 2,027 582 2,425 2,690 3,537 2,115 3,805 4,862 3,089 429   10,767,172 12,185,635
Net income   6,771 5,169 1,505 8,248 12,359 8,832 5,288 7,700 12,041 7,708 1,278   34,726,520 28,726,116
Net income per share attributable to common shareholders:                              
Basic (in usd per share)   $ 0.15 $ 0.12 $ 0.03 $ 0.19 $ 0.29 $ 0.21 $ 0.13 $ 0.19 $ 0.35 $ 0.56 $ 0.10   $ 0.82 $ 1.12
Diluted (in usd per share)   $ 0.15 $ 0.11 $ 0.03 $ 0.18 $ 0.27 $ 0.19 $ 0.12 $ 0.17 $ 0.28 $ 0.20 $ 0.03   $ 0.78 $ 0.69
Adjustment
                              
Statements of Income Data:                              
Operating income   0 0 0 0 0 0 0 0 0 0 0   0 0
Other expenses, net   59 350 (230) (195) 1,336 442 (269) (1,183) 741 1,154 500   1,313,587 1,212,450
Income before provision for income taxes   (59) (350) 230 195 (1,336) (442) 269 1,183 (741) (1,154) (500)   (1,313,587) (1,212,450)
Income tax provision   0 0 0 0 0 0 0 0 0 0 0   0 0
Net income   $ (59) $ (350) $ 230 $ 195 $ (1,336) $ (442) $ 269 $ 1,183 $ (741) $ (1,154) $ (500)   $ (1,313,587) $ (1,212,450)
Net income per share attributable to common shareholders:                              
Basic (in usd per share)   $ 0.00 $ (0.01) $ 0.01 $ 0.00 $ (0.03) $ (0.01)   $ 0.03 $ (0.02) $ (0.08) $ (0.04)   $ (0.03) $ (0.05)
Diluted (in usd per share)   $ 0.00 $ (0.01) $ 0.01   $ (0.03) $ (0.01)     $ (0.02) $ (0.03) $ (0.01)   $ (0.03) $ (0.03)