Securities (Schedule of Securities by Contractual Maturity) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Amortized Cost
Due in one year or less	$ 4,737
Due after one year through five years	17,524
Due after five years through ten years	73,405
Due after ten years	393,404
Amortized Cost	997,074	$ 834,850
Fair Value
Due in one year or less	4,806
Due after one year through five years	18,128
Due after five years through ten years	78,053
Due after ten years	413,025
Fair Value	1,036,910	854,825
MBS/CMO
Amortized Cost
MBS/CMO	508,004
Amortized Cost	508,004	526,907
Fair Value
MBS/CMO	522,898
Fair Value	$ 522,898	$ 530,525