Securities (Schedule of Securities by Contractual Maturity) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Securities Available-for-Sale: Amortized cost
Due in one year or less	$ 1,680
Due after one year through five years	19,818
Due after five years through ten years	78,342
Due after ten years	158,404
Amortized Cost	737,192	$ 719,555
Securities Available-for-Sale: Fair Value
Due in one year or less	1,699
Due after one year through five years	20,716
Due after five years through ten years	81,862
Due after ten years	162,219
Total Fair Value	741,710	709,786
MBS/CMO - Residential
Securities Available-for-Sale: Amortized cost
Amortized cost	478,595
Amortized Cost	478,595	471,852
Securities Available-for-Sale: Fair Value
Fair value	474,861
Total Fair Value	474,861	461,914
Equity Securities
Securities Available-for-Sale: Amortized cost
Amortized cost	353
Amortized Cost	353	353
Securities Available-for-Sale: Fair Value
Fair value	353
Total Fair Value	$ 353	$ 353