Loans Receivable and Allowance for Loan Losses - Number of Loans Modified and Their Pre-Modification and Post-Modification Investment Balances (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014 Contract	Sep. 30, 2013 Contract	Sep. 30, 2014 Contract	Sep. 30, 2013 Contract
Financing Receivable, Modifications [Line Items]
Number of Contracts	5	4	19	5
Pre-Modification Recorded Investment	$ 321	$ 3,607	$ 1,844	$ 4,131
Post-Modification Recorded Investment	299	3,607	1,755	4,131
Commercial Real Estate [Member] | Owner-Occupied [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	0	2	0	2
Pre-Modification Recorded Investment	0	150	0	150
Post-Modification Recorded Investment	0	150	0	150
Commercial Real Estate [Member] | Non-Owner Occupied [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	0	2	0	2
Pre-Modification Recorded Investment	0	3,457	0	3,457
Post-Modification Recorded Investment	0	3,457	0	3,457
Acquisition and Development [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts			0	1
Pre-Modification Recorded Investment			0	524
Post-Modification Recorded Investment			0	524
Residential Mortgage [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	4	0	18	0
Pre-Modification Recorded Investment	285	0	1,808	0
Post-Modification Recorded Investment	285	0	1,741	0
Installment and Other Loans [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts	1	0	1	0
Pre-Modification Recorded Investment	36	0	36	0
Post-Modification Recorded Investment	$ 14	$ 0	$ 14	$ 0