Commitments and Contingent Liabilities - Additional Information (Detail) (USD $)	6 Months Ended
	Jun. 30, 2014 plaintiff complaint	Dec. 31, 2013
Loss Contingencies [Line Items]
Notional amount of financial standby letters of credit	$ 286,000
Notional amount of performance standby letters of credit	500,000
Notional amount of commercial letters of credit	0
Financial instrument of credit risk	100,000	100,000
Number of new complaints	3
Loss Contingency, Number of Plaintiffs	36
Unused commitments and letters of credit [Member]
Loss Contingencies [Line Items]
Unfunded commitment liability	3,100,000	3,200,000
Other Matters [Member]
Loss Contingencies [Line Items]
Contingency reserve	100,000	800,000
Loss Contingency Paid	400,000
Accrued Loss Contingency Relieved	300,000
Other Matters [Member] | Minimum [Member]
Loss Contingencies [Line Items]
Number of customers affected (in customers)	700
Other Matters [Member] | Maximum [Member]
Loss Contingencies [Line Items]
Number of customers affected (in customers)	900
Pending Litigation [Member]
Loss Contingencies [Line Items]
Percentage Of Interest Rate On Deposits	3.50%
Number of Former Plaintiffs	34
Specified Average Age of Plaintiffs	62
Jarrett [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Loss Contingency, Number of Plaintiffs	8
Young [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Loss Contingency, Number of Plaintiffs	12
Fisanik [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Loss Contingency, Number of Plaintiffs	14
Ira Market Rate For Savings Account [Member] | Pending Litigation [Member]
Loss Contingencies [Line Items]
Percentage Of Interest Rate On Deposits	8.00%
Market Rate Savings Balance	4,000,000
Original Plaintiff [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Sought, Value	500,000
Original Plaintiff's Adult Children [Member]
Loss Contingencies [Line Items]
Loss Contingency, Damages Sought, Value	$ 800,000