Loans and allowance for loan losses (3) (Details) (USD $)
Sep. 30, 2012
Dec. 31, 2011
With no related allowance recorded [Abstract]    
Recorded investment $ 45,379,885 $ 34,623,937
Unpaid principal balance 54,024,599 36,856,805
With an allowance recorded [Abstract]    
Recorded investment 19,514,275 32,935,362
Unpaid principal balance 22,370,126 34,504,362
Related allowance 2,145,333 8,795,046
Total [Abstract]    
Recorded investment 64,894,160 67,559,299
Unpaid principal balance 76,394,725 71,361,167
Related Allowance 2,145,333 8,795,046
Commercial [Member]
   
With no related allowance recorded [Abstract]    
Recorded investment 9,219,142 9,722,132
Unpaid principal balance 15,132,049 11,094,408
With an allowance recorded [Abstract]    
Recorded investment 5,748,863 14,885,541
Unpaid principal balance 7,531,385 15,785,541
Related allowance 344,651 3,913,820
Total [Abstract]    
Recorded investment 14,968,005 24,607,673
Unpaid principal balance 22,663,434 26,879,949
Related Allowance 344,651 3,913,820
Residential [Member]
   
With no related allowance recorded [Abstract]    
Recorded investment 191,544 624,651
Unpaid principal balance 471,544 712,243
With an allowance recorded [Abstract]    
Recorded investment 0 587,235
Unpaid principal balance 0 587,235
Related allowance 0 320,250
Total [Abstract]    
Recorded investment 191,544 1,211,886
Unpaid principal balance 471,544 1,299,478
Related Allowance 0 320,250
Total construction and land development [Member]
   
With no related allowance recorded [Abstract]    
Recorded investment 9,410,686 10,346,783
Unpaid principal balance 15,603,593 11,806,651
With an allowance recorded [Abstract]    
Recorded investment 5,748,863 15,472,776
Unpaid principal balance 7,531,385 16,372,776
Related allowance 344,651 4,234,070
Total [Abstract]    
Recorded investment 15,159,549 25,819,559
Unpaid principal balance 23,134,978 28,179,427
Related Allowance 344,651 4,234,070
Farmland [Member]
   
With no related allowance recorded [Abstract]    
Recorded investment 1,049,489 0
Unpaid principal balance 1,049,489 0
With an allowance recorded [Abstract]    
Recorded investment   0
Unpaid principal balance   0
Related allowance   0
Total [Abstract]    
Recorded investment 1,049,489 0
Unpaid principal balance 1,049,489 0
Related Allowance 0 0
Commercial real estate - owner occupied [Member]
   
With no related allowance recorded [Abstract]    
Recorded investment 8,484,371 6,414,362
Unpaid principal balance 8,514,955 6,414,362
With an allowance recorded [Abstract]    
Recorded investment 7,101,305 9,508,393
Unpaid principal balance 7,616,761 9,652,393
Related allowance 917,527 2,031,740
Total [Abstract]    
Recorded investment 15,585,676 15,922,755
Unpaid principal balance 16,131,716 16,066,755
Related Allowance 917,527 2,031,740
Commercial real estate - non-owner occupied [Member]
   
With no related allowance recorded [Abstract]    
Recorded investment 12,915,719 7,146,531
Unpaid principal balance 13,061,948 7,146,531
With an allowance recorded [Abstract]    
Recorded investment 4,221,512 1,719,690
Unpaid principal balance 4,221,512 1,719,690
Related allowance 513,685 450,000
Total [Abstract]    
Recorded investment 17,137,231 8,866,221
Unpaid principal balance 17,283,460 8,866,221
Related Allowance 513,685 450,000
Multifamily [Member]
   
With no related allowance recorded [Abstract]    
Recorded investment 1,574,878 2,019,675
Unpaid principal balance 1,574,878 2,019,675
With an allowance recorded [Abstract]    
Recorded investment 0 0
Unpaid principal balance 0 0
Related allowance 0 0
Total [Abstract]    
Recorded investment 1,574,878 2,019,675
Unpaid principal balance 1,574,878 2,019,675
Related Allowance 0 0
Total commercial real estate [Member]
   
With no related allowance recorded [Abstract]    
Recorded investment 24,024,457 15,580,568
Unpaid principal balance 24,201,270 15,580,568
With an allowance recorded [Abstract]    
Recorded investment 11,322,817 11,228,083
Unpaid principal balance 11,838,273 11,372,083
Related allowance 1,431,212 2,481,740
Total [Abstract]    
Recorded investment 35,347,274 26,808,651
Unpaid principal balance 36,039,543 26,952,651
Related Allowance 1,431,212 2,481,740
Home equity lines [Member]
   
With no related allowance recorded [Abstract]    
Recorded investment 1,175,230 702,338
Unpaid principal balance 1,307,554 702,338
With an allowance recorded [Abstract]    
Recorded investment 399,312 756,892
Unpaid principal balance 447,596 756,892
Related allowance 79,550 233,606
Total [Abstract]    
Recorded investment 1,574,542 1,459,230
Unpaid principal balance 1,755,150 1,459,230
Related Allowance 79,550 233,606
Secured by 1-4 family residential, secured by first deeds of trust [Member]
   
With no related allowance recorded [Abstract]    
Recorded investment 9,328,458 6,319,837
Unpaid principal balance 10,460,195 6,792,837
With an allowance recorded [Abstract]    
Recorded investment 1,508,740 4,224,325
Unpaid principal balance 1,508,740 4,749,325
Related allowance 59,277 1,007,155
Total [Abstract]    
Recorded investment 10,837,198 10,544,162
Unpaid principal balance 11,968,935 11,542,162
Related Allowance 59,277 1,007,155
Secured by 1-4 family residential, secured by second deeds of trust [Member]
   
With no related allowance recorded [Abstract]    
Recorded investment 640,995 336,257
Unpaid principal balance 864,571 336,257
With an allowance recorded [Abstract]    
Recorded investment 117,002 167,523
Unpaid principal balance 117,002 167,523
Related allowance 105,997 119,524
Total [Abstract]    
Recorded investment 757,997 503,780
Unpaid principal balance 981,573 503,780
Related Allowance 105,997 119,524
Total consumer real estate [Member]
   
With no related allowance recorded [Abstract]    
Recorded investment 11,144,683 7,358,432
Unpaid principal balance 12,632,320 7,831,432
With an allowance recorded [Abstract]    
Recorded investment 2,025,054 5,148,740
Unpaid principal balance 2,073,338 5,673,740
Related allowance 244,824 1,360,285
Total [Abstract]    
Recorded investment 13,169,737 12,507,172
Unpaid principal balance 14,705,658 13,505,172
Related Allowance 244,824 1,360,285
Commercial and industrial loans (except those secured by real estate) [Member]
   
With no related allowance recorded [Abstract]    
Recorded investment 748,040 1,194,913
Unpaid principal balance 1,535,397 1,494,913
With an allowance recorded [Abstract]    
Recorded investment 417,541 818,597
Unpaid principal balance 927,130 818,597
Related allowance 124,646 452,773
Total [Abstract]    
Recorded investment 1,165,581 2,013,510
Unpaid principal balance 2,462,527 2,313,510
Related Allowance 124,646 452,773
Consumer and other [Member]
   
With no related allowance recorded [Abstract]    
Recorded investment 52,019 143,241
Unpaid principal balance 52,019 143,241
With an allowance recorded [Abstract]    
Recorded investment 0 267,166
Unpaid principal balance 0 267,166
Related allowance 0 266,178
Total [Abstract]    
Recorded investment 52,019 410,407
Unpaid principal balance 52,019 410,407
Related Allowance $ 0 $ 266,178