Investment Securities (Details 2) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014 item	Dec. 31, 2013 item	Jun. 30, 2013 item
Investment Securities Available-for-Sale, Total temporary impaired securities
Less than 12 months, Number	38	178	151
Less than 12 months, Fair Value	$ 51,327	$ 202,228	$ 138,877
Less than 12 months, Gross Unrealized Holding Losses	(252)	(4,925)	(3,652)
12 months or more, Number	56	1	17
12 months or more, Fair Value	70,551	12,607	713
12 months or more, Gross Unrealized Holding Losses	(1,227)	(913)	(138)
Total, Number	94	179	168
Total, Fair Value	121,878	214,835	139,590
Total, Gross Unrealized Holding Losses	(1,479)	(5,838)	(3,790)
Municipal bonds
Investment Securities Available-for-Sale, Total temporary impaired securities
Less than 12 months, Number	27	133	122
Less than 12 months, Fair Value	14,011	61,524	51,937
Less than 12 months, Gross Unrealized Holding Losses	(143)	(1,850)	(1,736)
12 months or more, Number	44
12 months or more, Fair Value	18,316
12 months or more, Gross Unrealized Holding Losses	(211)
Total, Number	71	133	122
Total, Fair Value	32,327	61,524	51,937
Total, Gross Unrealized Holding Losses	(354)	(1,850)	(1,736)
Mortgage-backed securities
Investment Securities Available-for-Sale, Total temporary impaired securities
Less than 12 months, Number	11	45	29
Less than 12 months, Fair Value	37,316	140,704	86,940
Less than 12 months, Gross Unrealized Holding Losses	(109)	(3,075)	(1,916)
12 months or more, Number	12	1	17
12 months or more, Fair Value	52,235	12,607	713
12 months or more, Gross Unrealized Holding Losses	(1,016)	(913)	(138)
Total, Number	23	46	46
Total, Fair Value	89,551	153,311	87,653
Total, Gross Unrealized Holding Losses	$ (1,125)	$ (3,988)	$ (2,054)