Allowance for Loan Losses - Additional Information (Detail) (USD $)	6 Months Ended	12 Months Ended
	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012
Accounts, Notes, Loans and Financing Receivable [Line Items]
Period of nonperforming loans	90 days
Nonaccruing loans excluded from impaired loan	$ 1,121,268	$ 721,951
Nonaccruing loans accrued interest	19,680	16,139
Trouble debt restructuring amount	0		3,800,000
Residential Mortgage [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Minimum balance in order to assign a risk rating grade	1,000,000
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Minimum balance in order to assign a risk rating grade	$ 250,000