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Fair Value of Assets and Liabilities (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Dec. 31, 2011
Available-for-sale: [Abstract]
Total available-for-sale securities	$ 510,027		$ 478,916
Impaired Loans Receivable [Abstract]
Carrying amount of loans with a specific allowance			3,007,000
Fair value of loans with a specific allowance			2,279,000
Specific Allowance			728,000
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	48		29
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	509,331		478,110
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	648		777
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	536	649
Transfers Into Level 3	0	0
Transfers out of Level 3	0	0
Total gains or losses [Abstract]
Included in net income	0	(246)
Included in other comprehensive income (loss)	189	586
Purchases, issuances, sales and settlements [Abstract]
Purchases	0	0
Issuances	0	0
Sales	0	0
Settlements	(77)	(5)
Ending Balance	648	984
Total gains or losses for the period included in net income attributable to the change in unrealized gains or losses related to assets and liabilities still held at the reporting date	0	(246)
U.S. Treasury Securities and Obligations of U.S. Government Corporations & Agencies [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	152,050		166,066
U.S. Treasury Securities and Obligations of U.S. Government Corporations & Agencies [Member] \| Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	0		0
U.S. Treasury Securities and Obligations of U.S. Government Corporations & Agencies [Member] \| Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	152,050		166,066
U.S. Treasury Securities and Obligations of U.S. Government Corporations & Agencies [Member] \| Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	0		0
Obligations of States and Political Subdivisions [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	48,991		41,202
Obligations of States and Political Subdivisions [Member] \| Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	0		0
Obligations of States and Political Subdivisions [Member] \| Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	48,991		41,202
Obligations of States and Political Subdivisions [Member] \| Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	0		0
Mortgage-backed Securities [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	298,835		261,833
Mortgage-backed Securities [Member] \| Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	0		0
Mortgage-backed Securities [Member] \| Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	298,835		261,775
Mortgage-backed Securities [Member] \| Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	0		58
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	0	68
Transfers Into Level 3	0	0
Transfers out of Level 3	0	0
Total gains or losses [Abstract]
Included in net income	0
Included in other comprehensive income (loss)	0
Purchases, issuances, sales and settlements [Abstract]
Purchases	0	0
Issuances	0	0
Sales	0	0
Settlements	0	(5)
Ending Balance	0	63
Total gains or losses for the period included in net income attributable to the change in unrealized gains or losses related to assets and liabilities still held at the reporting date	0	0
Trust Preferred Securities [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	648		719
Trust Preferred Securities [Member] \| Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	0		0
Trust Preferred Securities [Member] \| Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	0		0
Trust Preferred Securities [Member] \| Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	648		719
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	536	581
Transfers Into Level 3	0	0
Transfers out of Level 3	0	0
Total gains or losses [Abstract]
Included in net income	0	(246)
Included in other comprehensive income (loss)	189	586
Purchases, issuances, sales and settlements [Abstract]
Purchases	0	0
Issuances	0	0
Sales	0	0
Settlements	(77)	0
Ending Balance	648	921
Total gains or losses for the period included in net income attributable to the change in unrealized gains or losses related to assets and liabilities still held at the reporting date	0	(246)
Other Securities [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	9,503		9,096
Other Securities [Member] \| Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	48		29
Other Securities [Member] \| Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	9,455		9,067
Other Securities [Member] \| Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	$ 0		$ 0