Investment Securities, Contractual and Expected Maturity (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Maturity in years [Abstract]
Due in one year or less	$ 47,277
Due after one year through five years	58,881
Due after five years through ten years	5,462
Due after ten years	530
Subtotal	112,150
MBS & CMO	207,912
Amortized cost	320,062	$ 284,947
Maturity in years [Abstract]
Due in one year or less	47,114
Due after one year through five years	58,648
Due after five years through ten years	5,628
Due after ten years	536
Subtotal	111,926
MBS & CMO	202,711
Estimated fair value	$ 314,637	$ 280,741