Fair Value of Financial Instruments Fair Value by Balance Sheet Grouping (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents	$ 137,174	$ 48,832	$ 137,508	$ 43,736
Available-for-sale	478,775	478,698	466,785
Available-for-sale Securities, at Fair Value	478,775	478,698	466,785
Held-to-maturity	251,456	239,803	200,607
Federal Home Loan Bank and Federal Reserve Bank Stock	4,493	5,792	4,382
Net Loans	1,150,156	1,157,043	1,122,494
Accrued Interest Receivable	6,481	5,486	6,380
Deposits	1,851,206	1,731,155	1,760,878
Federal Funds Purchased and Securities Sold Under Agreements to Repurchase	12,166	12,678	16,652
Federal Home Loan Bank Term Advances	30,000	30,000	30,000
Junior Subordinated Obligations Issued to Unconsolidated Subsidiary Trusts	20,000	20,000	20,000
Accrued Interest Payable	523	584	974
Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents	137,174	48,832	137,508
Available-for-sale	478,775	478,698	466,785
Held-to-maturity	251,456	239,803	200,607
Federal Home Loan Bank and Federal Reserve Bank Stock	4,493	5,792	4,382
Net Loans	1,150,156	1,157,043	1,122,494
Accrued Interest Receivable	6,481	5,486	6,380
Deposits	1,851,206	1,731,155	1,760,878
Federal Funds Purchased and Securities Sold Under Agreements to Repurchase	12,166	12,678	16,652
Federal Home Loan Bank Term Advances	30,000	59,000	30,000
Junior Subordinated Obligations Issued to Unconsolidated Subsidiary Trusts	20,000	20,000	20,000
Accrued Interest Payable	523	584	974
Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	137,174	48,832	137,508
Available-for-sale Securities, at Fair Value	478,775	478,698	466,785
Securities Held-to-maturity, Fair Value Disclosure	259,562	248,252	207,779
Federal Home Loan Bank and Federal Reserve Bank Stock, Fair Value Disclosure	4,493	5,792	4,382
Net Loans, Fair Value Disclosure	1,167,063	1,192,628	1,147,014
Accrued Interest Receivable, Fair Value Disclosure	6,481	5,486	6,380
Deposits, Fair Value Disclosure	1,850,614	1,732,894	1,766,258
Federal Funds Purchased and Securities Sold under Agreements to Repurchase, Fair Value Disclosure	12,166	12,678	16,652
Federal Home Loan Bank Term Advances, Fair Value Disclosure	31,263	60,312	31,310
Junior Subordinated Obligations Issued to Unconsolidated Subsidiary Trusts, Fair Value Disclosure	20,000	20,000	20,000
Accrued Interest Payable, Fair Value Disclosure	523	584	974
Quoted Prices In Active Markets for Indentical Assets (Level 1) [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	137,174	48,832	137,508
Available-for-sale Securities, at Fair Value	0	0	281
Securities Held-to-maturity, Fair Value Disclosure	0	0	0
Federal Home Loan Bank and Federal Reserve Bank Stock, Fair Value Disclosure	4,493	5,792	4,382
Net Loans, Fair Value Disclosure	0	0	0
Accrued Interest Receivable, Fair Value Disclosure	6,481	5,486	6,380
Deposits, Fair Value Disclosure	1,575,954	1,447,882	1,421,257
Federal Funds Purchased and Securities Sold under Agreements to Repurchase, Fair Value Disclosure	12,166	12,678	16,652
Federal Home Loan Bank Term Advances, Fair Value Disclosure	0	29,000	0
Junior Subordinated Obligations Issued to Unconsolidated Subsidiary Trusts, Fair Value Disclosure	20,000	0	20,000
Accrued Interest Payable, Fair Value Disclosure	523	584	974
Significant Other Observable Inputs (Level 2) [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0	0	0
Available-for-sale Securities, at Fair Value	478,775	478,698	466,504
Securities Held-to-maturity, Fair Value Disclosure	259,562	248,252	207,779
Federal Home Loan Bank and Federal Reserve Bank Stock, Fair Value Disclosure	0	0	0
Net Loans, Fair Value Disclosure	0	0	0
Accrued Interest Receivable, Fair Value Disclosure	0	0	0
Deposits, Fair Value Disclosure	274,660	285,012	345,001
Federal Funds Purchased and Securities Sold under Agreements to Repurchase, Fair Value Disclosure	0	0	0
Federal Home Loan Bank Term Advances, Fair Value Disclosure	31,263	31,312	31,310
Junior Subordinated Obligations Issued to Unconsolidated Subsidiary Trusts, Fair Value Disclosure	0	20,000	0
Accrued Interest Payable, Fair Value Disclosure	0	0	0
Significant Unobservable Inputs (Level 3) [Member] | Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	0	0	0
Available-for-sale Securities, at Fair Value	0	0	0
Securities Held-to-maturity, Fair Value Disclosure	0	0	0
Federal Home Loan Bank and Federal Reserve Bank Stock, Fair Value Disclosure	0	0	0
Net Loans, Fair Value Disclosure	1,167,063	1,192,628	1,147,014
Accrued Interest Receivable, Fair Value Disclosure	0	0	0
Deposits, Fair Value Disclosure	0	0	0
Federal Funds Purchased and Securities Sold under Agreements to Repurchase, Fair Value Disclosure	0	0	0
Federal Home Loan Bank Term Advances, Fair Value Disclosure	0	0	0
Junior Subordinated Obligations Issued to Unconsolidated Subsidiary Trusts, Fair Value Disclosure	0	0	0
Accrued Interest Payable, Fair Value Disclosure	$ 0	$ 0	$ 0