Actual Capital Amounts and Ratios (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total Capital to Risk Weighted Assets, actual amount	$ 60,405	$ 53,206
Tier 1 Capital to Risk Weighted Assets, actual amount	51,865	48,122
Tier 1 Capital to Average Assets, actual amount	51,865	48,122
Total capital to risk weighted assets, actual ratio	12.50%	11.84%
Tier 1 capital to risk weighted assets, actual ratio	10.73%	10.73%
Tier 1 capital to average assets, actual ratio	9.29%	9.06%
Total Capital to Risk Weighted Assets, for capital adequacy purposes	38,655	35,580
Tier 1 Capital to Risk Weighted Assets, for capital adequacy purposes	19,328	17,790
Tier 1 Capital to Average Assets, for capital adequacy purposes	22,343	21,081
Total Capital to Risk Weighted Assets, to be well capitalized	48,319	44,475
Tier 1 Capital to Risk Weighted Assets, to be well capitalized	28,991	26,685
Tier 1 Capital to Average Assets, to be well capitalized	$ 27,929	$ 26,352
Minimum
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Total capital to risk weighted assets for capital adequacy purposes, Ratio	8.00%	8.00%
Tier 1 capital to risk weighted assets for capital adequacy purposes, Ratio	4.00%	4.00%
Tier 1 capital to average assets for capital adequacy purposes, Ratio	4.00%	4.00%
Total capital to risk weighted assets to be well capitalized under prompt corrective action, Ratio	10.00%	10.00%
Tier 1 Capital to Risk Weighted Assets to be well capitalized under prompt corrective action, Ratio	6.00%	6.00%
Tier 1 Capital to Average Assets to be well capitalized under prompt corrective action, Ratio	5.00%	5.00%