Fair Value Measurements (Details) (Fair Value Measurements Recurring [Member], USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	$ 641,823	$ 667,276	$ 610,493
Loans Held-for-sale	15,075
Total assets measured at fair value on a recurring basis	656,898
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	0	0	0
Loans Held-for-sale	0
Total assets measured at fair value on a recurring basis	0
Significant Other Observable Inputs (Level 2) [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	641,823	667,276	610,493
Loans Held-for-sale	15,075
Total assets measured at fair value on a recurring basis	656,898
Significant Unobservable Inputs (Level 3) [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	0	0	0
Loans Held-for-sale	0
Total assets measured at fair value on a recurring basis	0
Government sponsored agencies [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	101,492	70,679	74,561
Government sponsored agencies [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	0	0	0
Government sponsored agencies [Member] | Significant Other Observable Inputs (Level 2) [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	101,492	70,679	74,561
Government sponsored agencies [Member] | Significant Unobservable Inputs (Level 3) [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	0	0	0
State and political subdivisions [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	52,238	45,235	45,464
State and political subdivisions [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	0	0	0
State and political subdivisions [Member] | Significant Other Observable Inputs (Level 2) [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	52,238	45,235	45,464
State and political subdivisions [Member] | Significant Unobservable Inputs (Level 3) [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	0	0	0
Residential mortgage-backed securities [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	105,236	120,780	128,864
Residential mortgage-backed securities [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	0	0	0
Residential mortgage-backed securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	105,236	120,780	128,864
Residential mortgage-backed securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	0	0	0
Collateralized mortgage obligations [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	299,078	332,400	295,932
Collateralized mortgage obligations [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	0	0	0
Collateralized mortgage obligations [Member] | Significant Other Observable Inputs (Level 2) [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	299,078	332,400	295,932
Collateralized mortgage obligations [Member] | Significant Unobservable Inputs (Level 3) [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	0	0	0
Corporate bonds [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	82,106	96,768	64,184
Corporate bonds [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	0	0	0
Corporate bonds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	82,106	96,768	64,184
Corporate bonds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	0	0	0
Preferred stock [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	1,673	1,414	1,488
Preferred stock [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	0	0	0
Preferred stock [Member] | Significant Other Observable Inputs (Level 2) [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	1,673	1,414	1,488
Preferred stock [Member] | Significant Unobservable Inputs (Level 3) [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	$ 0	$ 0	$ 0