Securities (Summary of Gross Unrealized Losses and Fair Value of the Investments with Unrealized Losses) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value	$ 119,559	$ 242,695
Less than 12 Months Unrealized Losses	(871)	(2,023)
12 Months or More Fair Value	1,035	2,116
12 Months or More Unrealized Losses	(33)	(65)
Total Fair Value	120,594	244,811
Total Unrealized Losses	(904)	(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	85,516	238,875
Less than 12 Months Unrealized Losses	(664)	(1,999)
12 Months or More Fair Value	66	196
12 Months or More Unrealized Losses	(2)	(1)
Total Fair Value	85,582	239,071
Total Unrealized Losses	(666)	(2,000)
State and Municipal Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value	9,173	3,820
Less than 12 Months Unrealized Losses	(198)	(24)
12 Months or More Fair Value	0	950
12 Months or More Unrealized Losses	0	(34)
Total Fair Value	9,173	4,770
Total Unrealized Losses	(198)	(58)
U.S. Government and Government-Sponsored Enterprise Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value	24,870
Less than 12 Months Unrealized Losses	(9)
12 Months or More Fair Value	0
12 Months or More Unrealized Losses	0
Total Fair Value	24,870
Total Unrealized Losses	(9)
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	969	970
12 Months or More Unrealized Losses	(31)	(30)
Total Fair Value	969	970
Total Unrealized Losses	$ (31)	$ (30)