Securities (Summary of Gross Unrealized Losses and Fair Value of the Investments with Unrealized Losses) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value	$ 254,666	$ 242,695
Less than 12 Months Unrealized Losses	(5,923)	(2,023)
12 Months or More Fair Value	13,378	2,116
12 Months or More Unrealized Losses	(377)	(65)
Total Fair Value	268,044	244,811
Total Unrealized Losses	(6,300)	(2,088)
U.S. Government Agency and Government-Sponsored Enterprise Mortgage-Backed Securities and Collateralized Mortgage Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value	167,739	238,875
Less than 12 Months Unrealized Losses	(5,090)	(1,999)
12 Months or More Fair Value	12,204	196
12 Months or More Unrealized Losses	(336)	(1)
Total Fair Value	179,943	239,071
Total Unrealized Losses	(5,426)	(2,000)
State and Municipal Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value	20,413	3,820
Less than 12 Months Unrealized Losses	(383)	(24)
12 Months or More Fair Value	210	950
12 Months or More Unrealized Losses	(5)	(34)
Total Fair Value	20,623	4,770
Total Unrealized Losses	(388)	(58)
U.S. Government and Government-Sponsored Enterprise Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value	56,600
Less than 12 Months Unrealized Losses	(435)
12 Months or More Fair Value	0
12 Months or More Unrealized Losses	0
Total Fair Value	56,600
Total Unrealized Losses	(435)
US Treasury Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value	9,914
Less than 12 Months Unrealized Losses	(15)
12 Months or More Fair Value	0
12 Months or More Unrealized Losses	0
Total Fair Value	9,914
Total Unrealized Losses	(15)
Other Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value	0	0
Less than 12 Months Unrealized Losses	0	0
12 Months or More Fair Value	964	970
12 Months or More Unrealized Losses	(36)	(30)
Total Fair Value	964	970
Total Unrealized Losses	$ (36)	$ (30)