Allowance for Loan Losses - Company's Recorded Investment and Customers' Unpaid Principal Balances for Impaired Loans, with Associated Allowance Amount (Detail) (USD $)	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment	$ 3,063,849	$ 3,439,723
Customers' Unpaid Principal Balance	3,069,430	4,253,474
Related Allowance
Average Recorded Investment	2,985,960	3,385,145
Interest Income Recognized	58,350	79,186
Interest Income Collected	46,425	97,099
Recorded Investment	3,771,611	4,141,957
Customers' Unpaid Principal Balance	4,593,933	4,187,481
Related Allowance	831,679	833,883
Average Recorded Investment	3,723,766	3,109,017
Interest Income Recognized	59,955	116,268
Interest Income Collected	57,564	104,214
Recorded Investment	6,835,460	7,581,680
Customers' Unpaid Principal Balance	7,663,363	8,440,955
Related Allowance	831,679	833,883
Average Recorded Investment	6,709,726	6,494,162
Interest Income Recognized	118,305	195,454
Interest Income Collected	103,989	201,313
Construction, Land and Land Development [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment	13,070	213,768
Customers' Unpaid Principal Balance	13,705	213,914
Related Allowance
Average Recorded Investment	13,419	202,754
Interest Income Recognized		162
Interest Income Collected		130
Recorded Investment	200,000	61,882
Customers' Unpaid Principal Balance	200,000	65,566
Related Allowance	25,749	25,882
Average Recorded Investment	200,000	63,761
Recorded Investment	213,070	275,650
Customers' Unpaid Principal Balance	213,705	279,480
Related Allowance	25,749	25,882
Average Recorded Investment	213,419	266,515
Interest Income Recognized		162
Interest Income Collected		130
Farmland [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Related Allowance
Recorded Investment
Customers' Unpaid Principal Balance
Related Allowance
Average Recorded Investment
Interest Income Recognized
Interest Income Collected
Residential First Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment	1,968,483	1,495,910
Customers' Unpaid Principal Balance	1,968,483	1,495,910
Related Allowance
Average Recorded Investment	1,887,449	1,372,196
Interest Income Recognized	32,818	44,756
Interest Income Collected	27,206	59,727
Recorded Investment	1,842,897	2,782,380
Customers' Unpaid Principal Balance	1,842,897	2,807,875
Related Allowance	312,489	467,454
Average Recorded Investment	1,847,289	1,803,730
Interest Income Recognized	50,385	90,030
Interest Income Collected	50,320	82,370
Recorded Investment	3,811,380	4,278,290
Customers' Unpaid Principal Balance	3,811,380	4,303,785
Related Allowance	312,489	467,454
Average Recorded Investment	3,734,738	3,175,925
Interest Income Recognized	83,203	134,786
Interest Income Collected	77,526	142,097
Residential Revolving and Junior Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment	331,386
Customers' Unpaid Principal Balance	331,386
Related Allowance
Average Recorded Investment	331,268
Interest Income Recognized	10,697
Interest Income Collected	4,474
Recorded Investment	1,119,732
Customers' Unpaid Principal Balance	1,942,054
Related Allowance	306,423
Average Recorded Investment	1,067,665
Interest Income Recognized	3,771
Interest Income Collected	4,154
Recorded Investment	1,451,118
Customers' Unpaid Principal Balance	2,273,440
Related Allowance	306,423
Average Recorded Investment	1,398,933
Interest Income Recognized	14,468
Interest Income Collected	8,628
Commercial Mortgages (Non Owner Occupied) [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Related Allowance
Recorded Investment
Customers' Unpaid Principal Balance
Related Allowance
Average Recorded Investment
Interest Income Recognized
Interest Income Collected
Commercial Mortgages (Owner Occupied) [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment	750,910	758,391
Customers' Unpaid Principal Balance	755,856	758,391
Related Allowance
Average Recorded Investment	753,824	429,600
Interest Income Recognized	14,835	30,518
Interest Income Collected	14,745	34,754
Recorded Investment	536,772	858,610
Customers' Unpaid Principal Balance	536,772	858,610
Related Allowance	114,808	165,084
Average Recorded Investment	535,706	863,479
Interest Income Recognized	2,722	15,900
Interest Income Collected		11,961
Recorded Investment	1,287,682	1,617,001
Customers' Unpaid Principal Balance	1,292,628	1,617,001
Related Allowance	114,808	165,084
Average Recorded Investment	1,289,530	1,293,079
Interest Income Recognized	17,557	46,418
Interest Income Collected	14,745	46,715
Commercial and Industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Related Allowance
Recorded Investment
Customers' Unpaid Principal Balance
Related Allowance
Average Recorded Investment
Interest Income Recognized
Interest Income Collected
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Related Allowance
Recorded Investment	72,210	73,978
Customers' Unpaid Principal Balance	72,210	73,978
Related Allowance	72,210	74,210
Average Recorded Investment	73,106	67,322
Interest Income Recognized	3,077	8,385
Interest Income Collected	3,090	8,678
Recorded Investment	72,210	73,978
Customers' Unpaid Principal Balance	72,210	73,978
Related Allowance	72,210	74,210
Average Recorded Investment	73,106	67,322
Interest Income Recognized	3,077	8,385
Interest Income Collected	3,090	8,678
Residential Junior Mortgages [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Recorded Investment		971,654
Customers' Unpaid Principal Balance		1,785,259
Related Allowance
Average Recorded Investment		1,380,596
Interest Income Recognized		3,750
Interest Income Collected		2,488
Recorded Investment		365,107
Customers' Unpaid Principal Balance		381,452
Related Allowance		101,253
Average Recorded Investment		310,726
Interest Income Recognized		1,953
Interest Income Collected		1,205
Recorded Investment		1,336,761
Customers' Unpaid Principal Balance		2,166,711
Related Allowance		101,253
Average Recorded Investment		1,691,321
Interest Income Recognized		5,703
Interest Income Collected		$ 3,693