Securities Available-for-Sale (Details) - Investments classified by maturity date - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Securities Available-for-Sale:
Due in one year or less, amortized cost	$ 4,429
Due in one year or less, fair value	4,425
Due after one year through five years, amortized cost	36,607
Due after one year through five years, fair value	36,375
Due after five years through ten years, amortized cost	28,135
Due after five years through ten years, fair value	28,290
Due after ten years, amortized cost	150,398
Due after ten years, fair value	145,580
Total, amortized cost	421,147	$ 436,868
Total, fair value	410,039
Residential mortgage pass-through securities [Member]
Securities Available-for-Sale:
Total, amortized cost	196,650	183,509
Total, fair value	190,551
Commercial mortgage pass-through securities [Member]
Securities Available-for-Sale:
Total, amortized cost	3,953	4,054
Total, fair value	3,843
Other securities [Member]
Securities Available-for-Sale:
Total, amortized cost	975	$ 3,422
Total, fair value	$ 975