Securities (Held to maturity securities) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 257,927	$ 237,498
Gross Unrealized Gains	8,661	6,000
Gross Unrealized Losses	(3,419)	(6,061)
Estimated Fair Value	263,169	237,437
Mortgage-Backed Securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	5,933	5,973
Gross Unrealized Gains	245	199
Gross Unrealized Losses	(372)	(321)
Estimated Fair Value	5,806	5,851
Obligations of States and Political Subdivisions
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	251,994	231,525
Gross Unrealized Gains	8,416	5,801
Gross Unrealized Losses	(3,047)	(5,740)
Estimated Fair Value	$ 257,363	$ 231,586