Investment Securities, Gain Loss And Other Disclosures (Details) (USD $)	9 Months Ended
	Sep. 30, 2013 Security	Dec. 31, 2012	Sep. 30, 2012
Gain (Loss) on Investments [Line Items]
Number of investment securities held	352
Number of loss positions less than twelve months	60
Number of loss positions in twelve months or more	0
Percentage of bank qualified municipal bond portfolio rated (in hundredths)	94.00%
Percentage of portfolio not rated (in hundredths)	6.00%
Securities pledged to secure public deposits, FHLB borrowings, and other government agency deposits as required by law	$ 310,500,000	$ 296,900,000	$ 307,200,000
Government Agency Government Sponsored Entities [Member]
Gain (Loss) on Investments [Line Items]
Unrealized losses	0	0	0
Mortgage Backed Securities [Member]
Gain (Loss) on Investments [Line Items]
Unrealized losses	5,800,000	10,000	0
Obligations of States and Political Subdivisions [Member]
Gain (Loss) on Investments [Line Items]
Unrealized losses	741,000	3,000	0
Corporate Securities [Member]
Gain (Loss) on Investments [Line Items]
Unrealized losses	$ 185,000	$ 12,000	$ 0