Securities (Securities with Unrealized Losses, Presented by Length of Time Securities Have Been in Continuous Unrealized Loss Position) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value	$ 71,887	$ 403,858
Less than 12 Months Unrealized Loss	(578)	(13,850)
12 Months or More Fair Value	262,889	1,735
12 Months or More Unrealized Loss	(7,879)	(88)
Total Fair Value	334,776	405,593
Total Unrealized Loss	(8,457)	(13,938)
U.S. Treasury and Agency Securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value	0	18,952
Less than 12 Months Unrealized Loss	0	(1,048)
12 Months or More Fair Value	19,363	0
12 Months or More Unrealized Loss	(637)	0
Total Fair Value	19,363	18,952
Total Unrealized Loss	(637)	(1,048)
Obligations of State and Political Subdivisions
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value	4,849	38,878
Less than 12 Months Unrealized Loss	(35)	(899)
12 Months or More Fair Value	4,038	0
12 Months or More Unrealized Loss	(57)	0
Total Fair Value	8,887	38,878
Total Unrealized Loss	(92)	(899)
Mortgage-backed Securities - Residential
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value	67,038	346,028
Less than 12 Months Unrealized Loss	(543)	(11,903)
12 Months or More Fair Value	239,488	1,735
12 Months or More Unrealized Loss	(7,185)	(88)
Total Fair Value	306,526	347,763
Total Unrealized Loss	(7,728)	(11,991)
Equity Securities
Schedule of Available-for-sale Securities [Line Items]
Less than 12 Months Fair Value	0	0
Less than 12 Months Unrealized Loss	0	0
12 Months or More Fair Value	0	0
12 Months or More Unrealized Loss	0	0
Total Fair Value	0	0
Total Unrealized Loss	$ 0	$ 0