Long-Term Borrowings - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2009
Line of Credit Facility [Line Items]
Long term borrowings	$ 55,110,000	$ 75,220,000
Credit Suisse [Member]
Line of Credit Facility [Line Items]
Market value of mortgaged securities	67,000,000	73,800,000
Credit Suisse [Member] | $15 million borrowing [Member]
Line of Credit Facility [Line Items]
Debt instrument maturity date	Oct. 19, 2014
Debt instrument interest rate	2.03%	2.03%
Long term borrowings	15,000,000
Debt instrument interest rate description	Interest at a floating rate equal to 2.03% minus the greater of 3-month USD LIBOR less 1.50% or 0%, and was 2.03% at December 31, 2013 and 2012.
Credit Suisse [Member] | $40 million borrowing [Member]
Line of Credit Facility [Line Items]
Debt instrument maturity date	Jun. 21, 2015
Debt instrument interest rate	2.83%
Long term borrowings	40,000,000
Debt instrument interest rate description	Interest at a floating rate equal to 2.83% minus the greater of three-month USD LIBOR less 2.00% or 0%, and was 2.83% at December 31, 2013.
FNBB [Member]
Line of Credit Facility [Line Items]
Purchase of shares			50,000
Long term borrowings			550,000
Debt instrument maturity date	Dec. 22, 2014
Shares pledged as collateral	10,000	20,000
Long term borrowings	$ 110,000	$ 220,000
FNBB [Member] | Wall Street Journal Prime Rate [Member]
Line of Credit Facility [Line Items]
Debt instrument interest rate	3.25%	3.25%