Investment Securities - Unrealized Losses (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Fair Value
Less than 12 months	$ 19,130	$ 17,933
12 months or more	159,980	174,791
Total	179,110	192,724
Unrealized Losses
Less than 12 months	(87)	(80)
12 months or more	(2,776)	(4,416)
Total	(2,863)	(4,496)
U.S. Treasury
Fair Value
Less than 12 months	0	0
12 months or more	1,974	1,952
Total	1,974	1,952
Unrealized Losses
Less than 12 months	0	0
12 months or more	(11)	(32)
Total	(11)	(32)
U.S. government and federal agency obligations
Fair Value
Less than 12 months	0	0
12 months or more	9,515	9,966
Total	9,515	9,966
Unrealized Losses
Less than 12 months	0	0
12 months or more	(230)	(269)
Total	(230)	(269)
Government sponsored enterprises
Fair Value
Less than 12 months	500	1,997
12 months or more	32,036	33,346
Total	32,536	35,343
Unrealized Losses
Less than 12 months	0	(3)
12 months or more	(279)	(469)
Total	(279)	(472)
Obligations of states and political subdivisions
Fair Value
Less than 12 months	4,042	5,851
12 months or more	21,790	28,832
Total	25,832	34,683
Unrealized Losses
Less than 12 months	(14)	(16)
12 months or more	(225)	(485)
Total	(239)	(501)
Mortgage-backed securities
Fair Value
Less than 12 months	11,589	10,085
12 months or more	93,328	99,321
Total	104,917	109,406
Unrealized Losses
Less than 12 months	(72)	(61)
12 months or more	(1,882)	(3,049)
Total	(1,954)	(3,110)
Other debt securities
Fair Value
Less than 12 months	2,999
12 months or more	0
Total	2,999
Unrealized Losses
Less than 12 months	(1)
12 months or more	0
Total	(1)
Bank issued trust preferred securities
Fair Value
Less than 12 months	0	0
12 months or more	1,337	1,374
Total	1,337	1,374
Unrealized Losses
Less than 12 months	0	0
12 months or more	(149)	(112)
Total	$ (149)	$ (112)