Regulatory Capital Requirements (Details) (USD $)	Jun. 30, 2012	Dec. 31, 2011
Actual and statutory required capital amounts and ratios
Total risk-based capital to risk-weighted assets, ratio	12.00%
Tier 1 capital to average total assets	9.00%
Actual [Member]
Actual and statutory required capital amounts and ratios
Total risk-based capital to risk-weighted assets	$ 199,534,000	$ 196,710,000
Tier 1 capital to risk-weighted assets	184,155,000	179,521,000
Tier 1 capital to average total assets	184,155,000	179,521,000
Total risk-based capital to risk-weighted assets, ratio	16.43%	14.57%
Tier 1 capital to risk-weighted assets, ratio	15.16%	13.30%
Tier 1 capital to average total assets	9.32%	8.61%
Minimum Capital Requirements Per Bank Order [Member]
Actual and statutory required capital amounts and ratios
Total risk-based capital to risk-weighted assets	145,773,000	162,005,000
Tier 1 capital to average total assets	177,763,000	166,856,000
Total risk-based capital to risk-weighted assets, ratio	12.00%	12.00%
Tier 1 capital to average total assets	9.00%	8.00%
Minimum Capital Requirements Per Regulation [Member]
Actual and statutory required capital amounts and ratios
Total risk-based capital to risk-weighted assets	97,182,000	108,003,000
Tier 1 capital to average total assets	79,006,000	83,428,000
Total risk-based capital to risk-weighted assets, ratio	8.00%	8.00%
Tier 1 capital to average total assets	4.00%	4.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions [Member]
Actual and statutory required capital amounts and ratios
Total risk-based capital to risk-weighted assets	121,477,000	135,004,000
Tier 1 capital to risk-weighted assets	72,886,000	81,002,000
Tier 1 capital to average total assets	$ 98,757,000	$ 104,285,000
Total risk-based capital to risk-weighted assets, ratio	10.00%	10.00%
Tier 1 capital to risk-weighted assets, ratio	6.00%	6.00%
Tier 1 capital to average total assets	5.00%	5.00%