Interest Rate Swaps - Amounts and Locations of Activity Related to Back-to-Back Interest Rate Swaps within Corporation's Consolidated Balance Sheet (Detail) - USD ($)		12 Months Ended
	Aug. 01, 2008	Dec. 31, 2015
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]
Maturity date	Sep. 15, 2013
Third Party Interest Rate Swap [Member]
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]
Notional amount		$ 6,751,000
Maturity date		Aug. 01, 2025
Fixed rate		4.42%
Variable rate, description		1 month LIBOR + 2.25%
Variable rate		2.25%
Fair value		$ 131,000
Customer Interest Rate Swap [Member]
Schedule Of Loans And Allowance For Loan By Class Individually And Collectively Evaluated For Impairment [Line Items]
Notional amount		$ 6,751,000
Maturity date		Aug. 01, 2025
Fixed rate		4.42%
Variable rate, description		1 month LIBOR + 2.25%
Variable rate		2.25%
Fair value		$ (131,000)