Loans Receivable - Aging Analysis of Investment of Past Due Loans Receivable (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	$ 1,510	$ 2,193
60-89 Days Past Due	956	1,262
90 Days Or Greater	6,665	7,025
Total Past Due	9,131	10,480
Current	695,458	681,700
Total Loans Receivable	704,589	692,180
Recorded Investment greater than 90 Days and Accruing
Residential Real Estate, Single Family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	855	887
60-89 Days Past Due	383	420
90 Days Or Greater	3,515	3,343
Total Past Due	4,753	4,650
Current	330,666	321,355
Total Loans Receivable	335,419	326,005
Recorded Investment greater than 90 Days and Accruing
Residential Real Estate, Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due
60-89 Days Past Due
90 Days Or Greater
Total Past Due
Current	38,291	46,418
Total Loans Receivable	46,323	46,418
Recorded Investment greater than 90 Days and Accruing
Residential Real Estate Multi-Family [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due
60-89 Days Past Due
90 Days Or Greater
Total Past Due
Current	46,323	33,472
Total Loans Receivable	38,291	33,472
Recorded Investment greater than 90 Days and Accruing
Commercial Real Estate, Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	75	246
60-89 Days Past Due	397	598
90 Days Or Greater	2,631	3,211
Total Past Due	3,103	4,055
Current	76,196	77,022
Total Loans Receivable	79,299	81,077
Recorded Investment greater than 90 Days and Accruing
Commercial Real Estate, Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due
60-89 Days Past Due
90 Days Or Greater
Total Past Due
Current	16,816	15,878
Total Loans Receivable	16,816	15,878
Recorded Investment greater than 90 Days and Accruing
Consumer Home Equity [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	129	219
60-89 Days Past Due
90 Days Or Greater	237	223
Total Past Due	366	442
Current	81,827	79,976
Total Loans Receivable	82,193	80,418
Recorded Investment greater than 90 Days and Accruing
Dealer Auto and RV Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	433	771
60-89 Days Past Due	172	230
90 Days Or Greater	169	104
Total Past Due	774	1,105
Current	47,229	45,466
Total Loans Receivable	48,003	46,571
Recorded Investment greater than 90 Days and Accruing
Other Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	17	70
60-89 Days Past Due	4	12
90 Days Or Greater	80	109
Total Past Due	101	191
Current	6,996	7,705
Total Loans Receivable	7,097	7,896
Recorded Investment greater than 90 Days and Accruing
Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	1
60-89 Days Past Due		2
90 Days Or Greater	33	35
Total Past Due	34	37
Current	51,114	54,408
Total Loans Receivable	51,148	54,445
Recorded Investment greater than 90 Days and Accruing