Securities Available-for-Sale (Details) - Unrealized gains on investment securities - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Securities available-for-sale
Securities, Amortized Cost	$ 518,902	$ 419,947
Securities, Gross Unrealized Gains	2,916	1,297
Securities, Gross Unrealized Losses	(5,279)	(9,210)
Securities, Fair Value	516,539	412,034
Federal agency obligations [Member]
Securities available-for-sale
Securities, Amortized Cost	43,321	45,509
Securities, Gross Unrealized Gains	191	51
Securities, Gross Unrealized Losses	(232)	(605)
Securities, Fair Value	43,280	44,955
Residential mortgage pass-through securities [Member]
Securities available-for-sale
Securities, Amortized Cost	255,657	189,721
Securities, Gross Unrealized Gains	381	85
Securities, Gross Unrealized Losses	(2,837)	(4,602)
Securities, Fair Value	253,201	185,204
Commercial mortgage pass-through securities [Member]
Securities available-for-sale
Securities, Amortized Cost	6,903	3,919
Securities, Gross Unrealized Gains	23
Securities, Gross Unrealized Losses	(11)	(45)
Securities, Fair Value	6,915	3,874
Obligations of U.S. states and political subdivisions [Member]
Securities available-for-sale
Securities, Amortized Cost	167,819	141,496
Securities, Gross Unrealized Gains	2,115	1,091
Securities, Gross Unrealized Losses	(1,764)	(3,402)
Securities, Fair Value	168,170	139,185
Corporate bonds and notes [Member]
Securities available-for-sale
Securities, Amortized Cost	35,245	26,308
Securities, Gross Unrealized Gains	193	45
Securities, Gross Unrealized Losses	(367)	(540)
Securities, Fair Value	35,071	25,813
Asset-backed securities [Member]
Securities available-for-sale
Securities, Amortized Cost	8,244	9,685
Securities, Gross Unrealized Gains	11	22
Securities, Gross Unrealized Losses	(68)	(16)
Securities, Fair Value	8,187	9,691
Certificates of deposit [Member]
Securities available-for-sale
Securities, Amortized Cost	148	319
Securities, Gross Unrealized Gains	2	3
Securities, Gross Unrealized Losses
Securities, Fair Value	150	322
Other securities [Member]
Securities available-for-sale
Securities, Amortized Cost	1,565	2,990
Securities, Gross Unrealized Gains
Securities, Gross Unrealized Losses
Securities, Fair Value	$ 1,565	$ 2,990