Securities, Securities Available for Sale by Contractual Maturity (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018 USD ($) Security	Sep. 30, 2017 USD ($) Security	Dec. 31, 2017 USD ($)
Amortized Cost [Abstract]
Due in one year or less	$ 1,002
Due after one year through five years	7,017
Due after five years through ten years	23,675
Due after ten years	42,863
Amortized cost	74,557		$ 72,198
Fair Value [Abstract]
Due in one year or less	1,000
Due after one year through five years	6,843
Due after five years through ten years	22,932
Due after ten years	41,854
Total fair value	$ 72,629		$ 72,153
Number of securities sold | Security	0	0
Proceeds from calls and principal repayments	$ 10,187	$ 10,905
Fair value of securities purchased	12,400	26,800
Impairment losses on securities	$ 0	$ 0