Fair Value Measurements (Fair Value of Assets on a Recurring Basis) (Details) (Fair Value Measurements Recurring [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	$ 698,867	$ 582,054	$ 676,007
Loans Held-for-sale	14,850	17,665
Total assets measured at fair value on a recurring basis	713,717	599,719
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	0
Total assets measured at fair value on a recurring basis	0	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	698,867	582,054	676,007
Loans Held-for-sale	14,850	17,665
Total assets measured at fair value on a recurring basis	713,717	599,719
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	0
Government sponsored agencies [Member]
Summary of assets measured at fair value on a recurring basis
Total investment securities-available-for-sale	95,379	97,557	77,526
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	95,379	97,557	77,526
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	49,249	49,965	44,056
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	49,249	49,965	44,056
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	239,192	99,411	110,905
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	239,192	99,411	110,905
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	247,668	263,592	355,952
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	247,668	263,592	355,952
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	65,548	69,795	86,066
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	65,548	69,795	86,066
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	1,831	1,734	1,502
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	1,831	1,734	1,502
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