Loans Modified as Troubled Debt Restructuring (Detail) (USD $)	3 Months Ended	9 Months Ended
	Sep. 30, 2012 Contract	Sep. 30, 2012 Contract
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings, number of modification	1	7
Troubled debt restructurings, recorded investment	$ 10,797	$ 346,254
Mortgage loans on real estate | One-to-four family residential
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings, number of modification		1
Troubled debt restructurings, recorded investment		43,215
Mortgage loans on real estate | Home equity
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings, number of modification	1	2
Troubled debt restructurings, recorded investment		16,555
Agricultural business
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings, recorded investment	10,797	16,555
Commercial business
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings, number of modification		2
Troubled debt restructurings, recorded investment		268,450
Consumer loan
Financing Receivable, Modifications [Line Items]
Troubled debt restructurings, number of modification		2
Troubled debt restructurings, recorded investment		$ 18,034