Securities (Schedule of by Contractual Maturity) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Securities Available-for-Sale: Amortized cost
Due in one year or less	$ 6,173
Due after one year through five years	18,574
Due after five years through ten years	65,573
Due after ten years	98,066
Total Amortized Cost	617,996	$ 626,383
Securities Available-for-Sale, Fair Value
Due in one year or less	6,270
Due after one year through five years	18,694
Due after five years through ten years	68,131
Due after ten years	98,883
Total Fair Value	618,796	630,995
Securities Held-to-Maturity, Carrying Amount
Due in one year or less	95
Due after one year through five years	0
Due after five years through ten years	0
Due after ten years	0
Total Carrying Amount	95	184
Securities Held-to-Maturity, Fair Value
Due in one year or less	95
Due after one year through five years	0
Due after five years through ten years	0
Due after ten years	0
Total Fair Value	95	186
Mortgage-backed Securities - Residential
Securities Available-for-Sale: Amortized cost
Available-for-Sale, Amortized Cost	429,257
Total Amortized Cost	429,257	458,709
Securities Available-for-Sale, Fair Value
Available-for-Sale, Fair value	426,465
Total Fair Value	426,465	457,304
Equity Securities
Securities Available-for-Sale: Amortized cost
Available-for-Sale, Amortized Cost	353
Total Amortized Cost	353	353
Securities Available-for-Sale, Fair Value
Available-for-Sale, Fair value	353
Total Fair Value	$ 353	$ 353