Loans - Recorded Investment In Nonaccrual Loans By Class of Loans (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total nonaccrual and nonperforming loans	$ 7,927	$ 8,301
Real Estate [Member] | Non-owner occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total nonaccrual and nonperforming loans	1,839	1,910
Real Estate [Member] | Owner occupied [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total nonaccrual and nonperforming loans	1,293	446
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total nonaccrual and nonperforming loans	667	47
Single-family residential [Member] | Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total nonaccrual and nonperforming loans	44	736
Multi-family residential [Member] | Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total nonaccrual and nonperforming loans	3,937	4,996
Home equity lines of credit [Member] | Consumer [Member] | Originated for portfolio [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total nonaccrual and nonperforming loans	66	157
Home equity lines of credit [Member] | Consumer [Member] | Purchased for portfolio [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total nonaccrual and nonperforming loans	$ 81	$ 9