Investment Securities (Details) - Unrealized gains on investment securities - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Investment securities available-for-sale:
Investment Securities Available-for-Sale, Amortized Cost	$ 258,057	$ 281,461
Investment Securities Available-for-Sale, Gross Unrealized Gains	6,650	8,596
Investment Securities Available-for-Sale, Gross Unrealized Losses	(609)	(525)
Investment Securities Available-for-Sale, Fair Value	264,098	289,532
Investment securities held-to-maturity:
Investment Securities Held-to-Maturity, Amortized Cost	232,557	224,682
Investment Securities Held-to-Maturity, Gross Unrealized Gains	5,225	6,858
Investment Securities Held-to-Maturity, Gross Unrealized Losses	(577)	(95)
Investment Securities Held-to-Maturity, Fair Value	237,205	231,445
Total, Amortized Cost	490,614	506,143
Total, Gross Unrealized Gains	11,875	15,454
Total, Gross Unrealized Losses	(1,186)	(620)
Total, Fair Value	501,303	520,977
Federal Agency Obligations [Member]
Investment securities available-for-sale:
Investment Securities Available-for-Sale, Amortized Cost	30,713	32,650
Investment Securities Available-for-Sale, Gross Unrealized Gains	304	217
Investment Securities Available-for-Sale, Gross Unrealized Losses	(45)	(50)
Investment Securities Available-for-Sale, Fair Value	30,972	32,817
Investment securities held-to-maturity:
Investment Securities Held-to-Maturity, Amortized Cost	35,146	27,103
Investment Securities Held-to-Maturity, Gross Unrealized Gains	368	322
Investment Securities Held-to-Maturity, Gross Unrealized Losses	(140)	(28)
Investment Securities Held-to-Maturity, Fair Value	35,374	27,397
Residential Mortgage Backed Securities [Member]
Investment securities available-for-sale:
Investment Securities Available-for-Sale, Amortized Cost	53,624	58,836
Investment Securities Available-for-Sale, Gross Unrealized Gains	1,181	1,531
Investment Securities Available-for-Sale, Gross Unrealized Losses	(71)	(11)
Investment Securities Available-for-Sale, Fair Value	54,734	60,356
Investment securities held-to-maturity:
Investment Securities Held-to-Maturity, Amortized Cost	4,751	5,955
Investment Securities Held-to-Maturity, Gross Unrealized Gains	2	28
Investment Securities Held-to-Maturity, Gross Unrealized Losses	(28)
Investment Securities Held-to-Maturity, Fair Value	4,725	5,983
Commercial Mortgage Backed Securities [Member]
Investment securities available-for-sale:
Investment Securities Available-for-Sale, Amortized Cost	3,012	3,042
Investment Securities Available-for-Sale, Gross Unrealized Gains	11	4
Investment Securities Available-for-Sale, Fair Value	3,023	3,046
Investment securities held-to-maturity:
Investment Securities Held-to-Maturity, Amortized Cost	4,188	4,266
Investment Securities Held-to-Maturity, Gross Unrealized Gains	56	50
Investment Securities Held-to-Maturity, Gross Unrealized Losses	(1)
Investment Securities Held-to-Maturity, Fair Value	4,243	4,316
US States and Political Subdivisions Debt Securities [Member]
Investment securities available-for-sale:
Investment Securities Available-for-Sale, Amortized Cost	8,194	8,201
Investment Securities Available-for-Sale, Gross Unrealized Gains	164	205
Investment Securities Available-for-Sale, Fair Value	8,358	8,406
Investment securities held-to-maturity:
Investment Securities Held-to-Maturity, Amortized Cost	119,130	120,144
Investment Securities Held-to-Maturity, Gross Unrealized Gains	3,466	4,512
Investment Securities Held-to-Maturity, Gross Unrealized Losses	(277)	(60)
Investment Securities Held-to-Maturity, Fair Value	122,319	124,596
Trust Preferred Securities [Member]
Investment securities available-for-sale:
Investment Securities Available-for-Sale, Amortized Cost	16,087	16,086
Investment Securities Available-for-Sale, Gross Unrealized Gains	456	489
Investment Securities Available-for-Sale, Gross Unrealized Losses	(237)	(269)
Investment Securities Available-for-Sale, Fair Value	16,306	16,306
Corporate Bonds and Notes [Member]
Investment securities available-for-sale:
Investment Securities Available-for-Sale, Amortized Cost	105,518	119,838
Investment Securities Available-for-Sale, Gross Unrealized Gains	4,386	5,950
Investment Securities Available-for-Sale, Gross Unrealized Losses	(66)	(11)
Investment Securities Available-for-Sale, Fair Value	109,838	125,777
Investment securities held-to-maturity:
Investment Securities Held-to-Maturity, Amortized Cost	40,975	38,950
Investment Securities Held-to-Maturity, Gross Unrealized Gains	684	1,026
Investment Securities Held-to-Maturity, Gross Unrealized Losses	(131)	(7)
Investment Securities Held-to-Maturity, Fair Value	41,528	39,969
Asset-backed Securities [Member]
Investment securities available-for-sale:
Investment Securities Available-for-Sale, Amortized Cost	24,592	27,393
Investment Securities Available-for-Sale, Gross Unrealized Gains	103	140
Investment Securities Available-for-Sale, Gross Unrealized Losses	(13)	(31)
Investment Securities Available-for-Sale, Fair Value	24,682	27,502
Certificates of Deposit [Member]
Investment securities available-for-sale:
Investment Securities Available-for-Sale, Amortized Cost	2,096	2,098
Investment Securities Available-for-Sale, Gross Unrealized Gains	27	27
Investment Securities Available-for-Sale, Gross Unrealized Losses	(8)	(2)
Investment Securities Available-for-Sale, Fair Value	2,115	2,123
Equity Securities [Member]
Investment securities available-for-sale:
Investment Securities Available-for-Sale, Amortized Cost	376	376
Investment Securities Available-for-Sale, Gross Unrealized Losses	(49)	(69)
Investment Securities Available-for-Sale, Fair Value	327	307
Other Securities [Member]
Investment securities available-for-sale:
Investment Securities Available-for-Sale, Amortized Cost	13,845	12,941
Investment Securities Available-for-Sale, Gross Unrealized Gains	18	33
Investment Securities Available-for-Sale, Gross Unrealized Losses	(120)	(82)
Investment Securities Available-for-Sale, Fair Value	13,743	12,892
US Treasury Securities [Member]
Investment securities held-to-maturity:
Investment Securities Held-to-Maturity, Amortized Cost	28,367	28,264
Investment Securities Held-to-Maturity, Gross Unrealized Gains	649	920
Investment Securities Held-to-Maturity, Fair Value	$ 29,016	$ 29,184