Derivatives - Additional Information (Detail) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016 USD ($) Derivatives	Jun. 30, 2015 USD ($)	Jun. 30, 2016 USD ($) Derivatives	Jun. 30, 2015 USD ($)	Dec. 31, 2015 USD ($)
Risk participation Agreements [Line Items]
HedgedItemsOfCashFlowHedge	$ 200,000		$ 200,000
Derivative Instruments Designated As Hedging Instruments Interest Income	$ 424	$ 557	$ 854	$ 938
Risk Participation Agreements Purchased [Domain]
Risk participation Agreements [Line Items]
Number of interest rate swaps | Derivatives	22		22
Risk Participation Agreements Sold [Domain]
Risk participation Agreements [Line Items]
Number of interest rate swaps | Derivatives	7		7
Designated as Hedging Instrument [Member]
Risk participation Agreements [Line Items]
Derivative, Notional Amount	$ 200,000		$ 200,000		$ 200,000
Three Year Maturity [Member] | Designated as Hedging Instrument [Member]
Risk participation Agreements [Line Items]
Derivative, Notional Amount	85,000		85,000
Four Year Maturity [Member] | Designated as Hedging Instrument [Member]
Risk participation Agreements [Line Items]
Derivative, Notional Amount	$ 115,000		$ 115,000