Securities - Amortized Cost And Fair Value Of Securities By Contractual Maturity Of Available-For-Sale Securities (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Amortized Cost
Due in one year or less	$ 0
Due after one year through five years	0
Due after five years through ten years	4,952
Due after ten years	57,934
Total bonds and obligations	62,886
Securities available for sale, at amortized cost	176,149	$ 98,281
Fair Value
Due in one year or less	0
Due after one year through five years	0
Due after five years through ten years	4,877
Due after ten years	56,733
Total bonds and obligations	61,610
Securities available for sale, at fair value	172,658	98,730
U.S. government agencies
Amortized Cost
Securities available for sale, at amortized cost	26,718	18,799
Fair Value
Securities available for sale, at fair value	26,325	18,861
U.S. government-sponsored enterprises
Amortized Cost
Securities available for sale, at amortized cost	17,490	6,054
Fair Value
Securities available for sale, at fair value	17,524	6,061
Mortgage-backed securities - U.S. government-sponsored enterprises
Amortized Cost
Securities available for sale, at amortized cost	69,055	30,958
Fair Value
Securities available for sale, at fair value	$ 67,199	$ 30,544