Fair Value (Additional Information) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Securities	$ 608,653		$ 608,653		$ 587,602
Loan held for sale, at fair value	9,054		9,054		16,641
Contractual principal balance of Loan held for sale	8,937		8,937		16,413
Difference in amount of loan held for sale	117		117		228
Impaired loans, carrying amount	4,947		4,947		8,274
Valuation allowance for loans losses	3,690		3,690		5,411
Provision for Loan Losses	229		608		2,320
Other real estate, carrying value	290		290		150
Cost of Real Estate Sales		100	301	100
Provision For Loan Lease And Other Losses		393		1,023
Fair Value, Measurements, Recurring [Member] | Obligations of State and Political Subdivisions [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Securities	97,271		97,271		76,485
Fair Value, Measurements, Recurring [Member] | Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Securities	1,026		1,026		733
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Securities	11,355		11,355		12,522
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Obligations of State and Political Subdivisions [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Securities	11,002		11,002		12,169
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Equity Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Securities	$ 353		$ 353		$ 353