Investment Securities (Details 2) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014 item	Dec. 31, 2013 item	Sep. 30, 2013 item
Investment Securities Available-for-Sale, Total temporary impaired securities
Less than 12 months, Number	51	178	170
Less than 12 months, Fair Value	$ 102,052	$ 202,228	$ 196,696
Less than 12 months, Gross Unrealized Holding Losses	(439)	(4,925)	(4,520)
12 months or more, Number	35	1	1
12 months or more, Fair Value	52,975	12,607	13,117
12 months or more, Gross Unrealized Holding Losses	(1,093)	(913)	(860)
Total, Number	86	179	171
Total, Fair Value	155,027	214,835	209,813
Total, Gross Unrealized Holding Losses	(1,532)	(5,838)	(5,380)
Municipal bonds
Investment Securities Available-for-Sale, Total temporary impaired securities
Less than 12 months, Number	29	133	131
Less than 12 months, Fair Value	16,804	61,524	60,183
Less than 12 months, Gross Unrealized Holding Losses	(183)	(1,850)	(1,795)
12 months or more, Number	26
12 months or more, Fair Value	10,459
12 months or more, Gross Unrealized Holding Losses	(85)
Total, Number	55	133	131
Total, Fair Value	27,263	61,524	60,183
Total, Gross Unrealized Holding Losses	(268)	(1,850)	(1,795)
Mortgage-backed securities
Investment Securities Available-for-Sale, Total temporary impaired securities
Less than 12 months, Number	22	45	39
Less than 12 months, Fair Value	85,248	140,704	136,513
Less than 12 months, Gross Unrealized Holding Losses	(256)	(3,075)	(2,725)
12 months or more, Number	9	1	1
12 months or more, Fair Value	42,516	12,607	13,117
12 months or more, Gross Unrealized Holding Losses	(1,008)	(913)	(860)
Total, Number	31	46	40
Total, Fair Value	127,764	153,311	149,630
Total, Gross Unrealized Holding Losses	$ (1,264)	$ (3,988)	$ (3,585)