Fair Value of Assets and Liabilities (Details) (USD $)	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Available-for-sale: [Abstract]
Total available-for-sale securities	$ 525,752,000		$ 478,916,000
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	777,000	649,000
Transfers Into Level 3	0	0
Transfers out of Level 3	(58,000)	0
Total gains or losses [Abstract]
Included in net income	0	(584,000)
Included in other comprehensive income (loss)	383,000	723,000
Purchases, issuances, sales and settlements [Abstract]
Purchases	0	0
Issuances	0	0
Sales	0	0
Settlements	(652,000)	(24,000)
Ending Balance	450,000	764,000
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	584,000
Impaired Loans Receivable [Abstract]
Carrying amount of loans with a specific allowance	2,642,000		3,216,000
Fair value of loans with a specific allowance	2,227,000		2,700,000
Specific Allowance	768,000		575,000
Fair Value, Measurements, Recurring [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	525,752,000		478,916,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	48,000		29,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	525,254,000		478,110,000
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	450,000		777,000
Fair Value, Measurements, Nonrecurring [Member]
Impaired Loans Receivable [Abstract]
Carrying amount of loans with a specific allowance	3,542,000
Fair value of loans with a specific allowance	2,851,000
Specific Allowance	691,000
U.S. Treasury Securities and Obligations of U.S. Government Corporations & Agencies [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	175,475,000		166,066,000
U.S. Treasury Securities and Obligations of U.S. Government Corporations & Agencies [Member] | Fair Value, Measurements, Recurring [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	175,475,000		166,066,000
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	175,475,000		166,066,000
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	54,611,000		41,202,000
Obligations of States and Political Subdivisions [Member] | Fair Value, Measurements, Recurring [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	54,611,000		41,202,000
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	54,611,000		41,202,000
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	285,412,000		261,833,000
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	58,000	68,000
Transfers Into Level 3	0	0
Transfers out of Level 3	(58,000)	0
Total gains or losses [Abstract]
Included in net income	0	0
Included in other comprehensive income (loss)	0	0
Purchases, issuances, sales and settlements [Abstract]
Purchases	0	0
Issuances	0	0
Sales	0	0
Settlements	0	(7,000)
Ending Balance	0	61,000
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
Mortgage-backed Securities [Member] | Fair Value, Measurements, Recurring [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	285,412,000		261,833,000
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	285,412,000		261,775,000
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		58,000
Trust Preferred Securities [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	450,000		719,000
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	719,000	581,000
Transfers Into Level 3	0	0
Transfers out of Level 3	0	0
Total gains or losses [Abstract]
Included in net income	0	(584,000)
Included in other comprehensive income (loss)	383,000	723,000
Purchases, issuances, sales and settlements [Abstract]
Purchases	0	0
Issuances	0	0
Sales	0	0
Settlements	(652,000)	(17,000)
Ending Balance	450,000	703,000
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	584,000
Trust Preferred Securities [Member] | Fair Value, Measurements, Recurring [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	450,000		719,000
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	450,000		719,000
Other Securities [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	9,804,000		9,096,000
Other Securities [Member] | Fair Value, Measurements, Recurring [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	9,804,000		9,096,000
Other Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	48,000		29,000
Other Securities [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Available-for-sale: [Abstract]
Total available-for-sale securities	9,756,000		9,067,000
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