Investment Securities (Maturity Schedule) (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Amortized Cost
Total, amortized cost	$ 390,324
Estimated Fair Value
Estimated fair value	381,367	$ 350,040	[1]
Amortized Cost
Total, amortized cost	156,648	142,461	[1]
Estimated Fair Value
Estimated fair value	153,589	140,875	[1]
US Government-sponsored Enterprises Debt Securities [Member]
Amortized Cost
Due after one year through five years, amortized cost	2,016
Estimated Fair Value
Due after one year through five years, estimated fair value	2,028
Estimated fair value	2,028	2,044
Residential Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Amortized Cost
Due after five years through 10 years	2,055
Due after ten years	298,467
Estimated Fair Value
Due after five years through 10 years	2,109
Due after ten years	289,386
Estimated fair value	291,495	290,145
Amortized Cost
Due after ten years	126,977
Estimated Fair Value
Due after ten years	124,192
Estimated fair value	124,192	130,877
Residential Mortgage-backed Securities, Issued by Private Enterprises [Member]
Amortized Cost
Due after ten years	15,228
Estimated Fair Value
Due after ten years	15,908
Estimated fair value	15,908	17,271
Amortized Cost
Due after ten years	19,609
Estimated Fair Value
Due after ten years	19,524
Estimated fair value	19,524
Commercial mortgage-backed securities - GSE [Member]
Amortized Cost
Due after five years through 10 years	22,180
Estimated Fair Value
Due after five years through 10 years	21,872
Estimated fair value	21,872	21,958
Commercial Mortgage-backed Securities, Issued by Private Enterprises [Member]
Amortized Cost
Due after ten years	19,497
Estimated Fair Value
Due after ten years	19,236
Estimated fair value	19,236	10,215
Amortized Cost
Due after ten years	10,062
Estimated Fair Value
Due after ten years	9,873
Estimated fair value	9,873	9,998
Corporate notes [Member]
Amortized Cost
Due after one year through five years, amortized cost	30,881
Estimated Fair Value
Due after one year through five years, estimated fair value	30,828
Estimated fair value	$ 30,828	$ 8,407

[1] Derived from audited consolidated financial statements