Regulatory Matters (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Company [Member]
Total Capital (to Risk-Weighted Assets)
Total Capital (to Risk-Weighted Assets), Actual	$ 774,809	$ 741,073
Total Capital (to Risk-Weighted Assets), Ratio	19.05%	18.00%
Total Capital (to Risk-Weighted Assets), For Capital Adequacy	325,379	329,366
Tier 1 Capital (to Risk-Weighted Assets)
Tie 1 Capital (to Risk-Weighted Assets), Actual	723,329	683,811
Tier 1 Capital (to Risk-Weighted Assets), Ratio	17.79%	16.61%
Tie 1 Capital (to Risk-Weighted Assets), For Capital Adequacy	162,637	164,675
Tier 1 Capital (to Average-Assets)
Tier 1 Capital (to Average-Assets), Actual	723,329	683,811
Tier 1 Capital (to Average-Assets), Ratio	11.19%	10.58%
Tier 1 Capital (to Average-Assets), For Capital Adequacy	258,563	258,530
Bank [Member]
Total Capital (to Risk-Weighted Assets)
Total Capital (to Risk-Weighted Assets), Actual	756,702	732,896
Total Capital (to Risk-Weighted Assets), Ratio	18.63%	17.82%
Total Capital (to Risk-Weighted Assets), For Capital Adequacy	324,939	329,022
Total Capital (to Risk-Weighted Assets), Required to be Well Capitalized	406,174	411,277
Tier 1 Capital (to Risk-Weighted Assets)
Tie 1 Capital (to Risk-Weighted Assets), Actual	705,273	680,680
Tier 1 Capital (to Risk-Weighted Assets), Ratio	17.36%	16.55%
Tie 1 Capital (to Risk-Weighted Assets), For Capital Adequacy	162,505	164,515
Tier 1 Capital (to Risk-Weighted Assets), Required to be Well Capitalized	243,758	246,772
Tier 1 Capital (to Average-Assets)
Tier 1 Capital (to Average-Assets), Actual	705,273	680,680
Tier 1 Capital (to Average-Assets), Ratio	10.92%	10.54%
Tier 1 Capital (to Average-Assets), For Capital Adequacy	258,342	258,323
Tier 1 Capital (to Average-Assets), Required to be Well Capitalized	$ 322,927	$ 322,903
Bank [Member] | Minimum [Member]
Total Capital (to Risk-Weighted Assets)
Total Capital (to Risk-Weighted Assets), For Capital Adequacy, Ratio	8.00%	8.00%
Total Capital (to Risk-Weighted Assets), Required to be Well Capitalized, Ratio	10.00%	10.00%
Tier 1 Capital (to Risk-Weighted Assets)
Tier 1 Capital (to Risk-Weighted Assets), For Capital Adequacy, Ratio	4.00%	4.00%
Tier 1 Capital (to Risk-Weighted Assets), Required to be Well Capitalized, Ratio	6.00%	6.00%
Tier 1 Capital (to Average-Assets)
Tier 1 Capital (to Average-Assets), For Capital Adequacy, Ratio	4.00%	4.00%
Tier 1 Capital (to Average-Assets), Required to be Well Capitalized, Ratio	5.00%	5.00%