Derivatives - Additional Information (Detail) (USD $)	Sep. 30, 2014
Risk participation Agreements [Line Items]
HedgedItemsOfCashFlowHedge	$ 100,000,000
Risk Participation Agreements Purchased [Domain]
Risk participation Agreements [Line Items]
Number of interest rate swaps	13
Risk Participation Agreements Sold [Domain]
Risk participation Agreements [Line Items]
Number of interest rate swaps	4
InterestRateSwapThreeYearLife [Member]
Risk participation Agreements [Line Items]
Derivative, Notional Amount	50,000,000
InterestRateSwapFourYearLife [Member] [Member]
Risk participation Agreements [Line Items]
Derivative, Notional Amount	$ 50,000,000