Loans - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013 SecurityLoan	Dec. 31, 2012	Dec. 31, 2011
Accounts, Notes, Loans and Financing Receivable [Line Items]
Amount of net premiums and net discounts included in gross loans	$ 53,000	$ 24,000
Period of loan past due	90 days
Frequency of external appraisals updating	Six to twelve months
Age of appraisal that will considered as stale	1 year
Additional interest income, net of tax	722,000	759,000	354,000
Impaired loans	42,141,000	47,660,000
Percentage of collateral coverage to loan balance	100.00%
Obligations to lend additional funds on restructured loans	0	0
Troubled debt restructurings	33,400,000	24,700,000
Performing according to their restructured terms	108
TDRs percentage of gross portfolio loans	5.59%	3.71%
Doubtful grade remaining outstanding period	6 months
Allowance for loan and lease losses	14,172,000	11,103,000	10,622,000
Percentage of allowance for loan and lease losses	2.37%	1.67%
Impaired loans, Related Allowance	4,994,000	2,301,000
Reserve for off balance sheet commitments	698,000	499,000
Company reclassified mortgage loans held-for-sale	65,100,000	65,100,000
Loans and leases receivable, Other information	Approximately 70% of our gross loan portfolio is secured by real estate, and a significant decline in real estate market values may require an increase in the ALLL.
Percentage of loan portfolio is secured by real estate	70.00%
Percentage of unallocated allowance amount out of ALLL	13.00%	7.00%
Maximum loan-to-value percentage	80.00%
Performing [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired loans	8,800,000	8,600,000
Performing according to their restructured terms	102
Real estate - ITIN loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Impaired loans, Related Allowance	1,300,000	1,500,000
Commitments to extend credit [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance allocation ITIN portfolio commitments to extend credit	$ 192,000,000