Investment Securities (Details) - Unrealized gains on investment securities - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Investment securities available-for-sale
Investment Securities Available-for-Sale, Amortized Cost	$ 436,868	$ 351,928
Investment Securities Available-for-Sale, Gross Unrealized Gains	2,886	4,645
Investment Securities Available-for-Sale, Gross Unrealized Losses	(4,470)	(3,283)
Investment Securities Available-for-Sale, Fair Value	435,284	353,290
Federal Agency Obligations [Member]
Investment securities available-for-sale
Investment Securities Available-for-Sale, Amortized Cost	56,297	52,826
Investment Securities Available-for-Sale, Gross Unrealized Gains	141	282
Investment Securities Available-for-Sale, Gross Unrealized Losses	(416)	(271)
Investment Securities Available-for-Sale, Fair Value	56,022	52,837
Residential Mortgage Backed Securities [Member]
Investment securities available-for-sale
Investment Securities Available-for-Sale, Amortized Cost	183,509	72,922
Investment Securities Available-for-Sale, Gross Unrealized Gains	330	519
Investment Securities Available-for-Sale, Gross Unrealized Losses	(1,948)	(944)
Investment Securities Available-for-Sale, Fair Value	181,891	72,497
Commercial Mortgage Backed Securities [Member]
Investment securities available-for-sale
Investment Securities Available-for-Sale, Amortized Cost	4,054	4,186
Investment Securities Available-for-Sale, Gross Unrealized Gains	3	23
Investment Securities Available-for-Sale, Gross Unrealized Losses	(3)
Investment Securities Available-for-Sale, Fair Value	4,054	4,209
US States and Political Subdivisions Debt Securities [Member]
Investment securities available-for-sale
Investment Securities Available-for-Sale, Amortized Cost	130,723	148,747
Investment Securities Available-for-Sale, Gross Unrealized Gains	1,739	2,789
Investment Securities Available-for-Sale, Gross Unrealized Losses	(1,334)	(931)
Investment Securities Available-for-Sale, Fair Value	131,128	150,605
Trust Preferred Securities [Member]
Investment securities available-for-sale
Investment Securities Available-for-Sale, Amortized Cost	4,577	5,575
Investment Securities Available-for-Sale, Gross Unrealized Gains	205	242
Investment Securities Available-for-Sale, Gross Unrealized Losses	(111)	(151)
Investment Securities Available-for-Sale, Fair Value	4,671	5,666
Corporate Bonds And Notes [Member]
Investment securities available-for-sale
Investment Securities Available-for-Sale, Amortized Cost	29,801	36,717
Investment Securities Available-for-Sale, Gross Unrealized Gains	163	586
Investment Securities Available-for-Sale, Gross Unrealized Losses	(271)	(375)
Investment Securities Available-for-Sale, Fair Value	29,693	36,928
Asset-backed Securities [Member]
Investment securities available-for-sale
Investment Securities Available-for-Sale, Amortized Cost	12,021	14,867
Investment Securities Available-for-Sale, Gross Unrealized Gains	66	2
Investment Securities Available-for-Sale, Gross Unrealized Losses	(37)	(286)
Investment Securities Available-for-Sale, Fair Value	12,050	14,583
Certificates of Deposit [Member]
Investment securities available-for-sale
Investment Securities Available-for-Sale, Amortized Cost	621	973
Investment Securities Available-for-Sale, Gross Unrealized Gains	4	10
Investment Securities Available-for-Sale, Gross Unrealized Losses
Investment Securities Available-for-Sale, Fair Value	625	983
Equity Securities [Member]
Investment securities available-for-sale
Investment Securities Available-for-Sale, Amortized Cost	11,843	11,843
Investment Securities Available-for-Sale, Gross Unrealized Gains	235	192
Investment Securities Available-for-Sale, Gross Unrealized Losses	(350)	(325)
Investment Securities Available-for-Sale, Fair Value	11,728	11,710
Other Securities [Member]
Investment securities available-for-sale
Investment Securities Available-for-Sale, Amortized Cost	3,422	3,272
Investment Securities Available-for-Sale, Gross Unrealized Gains
Investment Securities Available-for-Sale, Gross Unrealized Losses
Investment Securities Available-for-Sale, Fair Value	$ 3,422	$ 3,272