Loans - Summary of Troubled Debt Restructurings (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013 Contract	Jun. 30, 2012 Contract	Jun. 30, 2013 Contract	Jun. 30, 2012 Contract
Financing Receivable, Modifications [Line Items]
Number of loans restructured	2	6	2	8
Pre- Modification Recorded Investment	$ 76	$ 473	$ 76	$ 628
Post- Modification Recorded Investment	76	473	76	628
Commercial [Member]
Financing Receivable, Modifications [Line Items]
Number of loans restructured	2		2
Pre- Modification Recorded Investment	76		76
Post- Modification Recorded Investment	76		76
Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of loans restructured		5		7
Pre- Modification Recorded Investment		333		488
Post- Modification Recorded Investment		333		488
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of loans restructured		1		1
Pre- Modification Recorded Investment		140		140
Post- Modification Recorded Investment		$ 140		$ 140