Loans Receivable - Average Recorded Investment and Interest Income Recognized on Loans (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Commercial Real Estate [Member]
Schedule Of Financial Receivables [Line Items]
Average Recorded Investment	$ 14,738	$ 13,699	$ 13,837	$ 13,841
Interest Income Recognized	173	163	551	489
Residential Real Estate, Single Family [Member]
Schedule Of Financial Receivables [Line Items]
Average Recorded Investment	1,358	1,361	1,359	1,362
Interest Income Recognized	3	2	7	7
Residential Construction Loans [Member]
Schedule Of Financial Receivables [Line Items]
Average Recorded Investment	885	102	894	421
Interest Income Recognized	7	10	25	32
Consumer [Member]
Schedule Of Financial Receivables [Line Items]
Average Recorded Investment	382	243	367	196
Interest Income Recognized	7	11	20	16
Commercial [Member]
Schedule Of Financial Receivables [Line Items]
Average Recorded Investment		37		41
Interest Income Recognized		2		2
With No Related Allowance Recorded [Member] | Commercial Real Estate [Member]
Schedule Of Financial Receivables [Line Items]
Average Recorded Investment	5,562	5,451	5,325	5,488
Interest Income Recognized	57	58	177	170
With No Related Allowance Recorded [Member] | Residential Real Estate, Single Family [Member]
Schedule Of Financial Receivables [Line Items]
Average Recorded Investment	1,358	1,361	1,359	1,362
Interest Income Recognized	3	2	7	7
With No Related Allowance Recorded [Member] | Residential Construction Loans [Member]
Schedule Of Financial Receivables [Line Items]
Average Recorded Investment	885	102	894	421
Interest Income Recognized	7	10	25	32
With No Related Allowance Recorded [Member] | Consumer Home Equity [Member]
Schedule Of Financial Receivables [Line Items]
Average Recorded Investment	198	91	179	43
Interest Income Recognized	4	10	10	10
With No Related Allowance Recorded [Member] | Dealer Auto and RV Loans [Member]
Schedule Of Financial Receivables [Line Items]
Average Recorded Investment	9		10
Interest Income Recognized			2
With an Allowance Recorded [Member] | Commercial Real Estate [Member]
Schedule Of Financial Receivables [Line Items]
Average Recorded Investment	9,176	8,248	8,512	8,353
Interest Income Recognized	116	105	374	319
With an Allowance Recorded [Member] | Consumer Home Equity [Member]
Schedule Of Financial Receivables [Line Items]
Average Recorded Investment	172	152	174	153
Interest Income Recognized	3	1	8	6
With an Allowance Recorded [Member] | Dealer Auto and RV Loans [Member]
Schedule Of Financial Receivables [Line Items]
Average Recorded Investment	3		4
Interest Income Recognized
With an Allowance Recorded [Member] | Commercial Business Loans [Member]
Schedule Of Financial Receivables [Line Items]
Average Recorded Investment		37		41
Interest Income Recognized		$ 2		$ 2