Investment Securities (Maturity Schedule) (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Amortized Cost
Total	$ 379,125
Estimated Fair Value
Total	375,929	$ 350,040	[1]
Amortized Cost
Total	152,670	142,461	[1]
Estimated Fair Value
Total	151,935	140,875	[1]
US Government-sponsored Enterprises Debt Securities [Member]
Amortized Cost
Due after one year through five years, amortized cost	2,011
Estimated Fair Value
Due after one year through five years, estimated fair value	2,019
Total	2,019	2,044
Residential Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Amortized Cost
Due after five years through 10 years	1,930
Due after ten years	290,025
Estimated Fair Value
Due after five years through 10 years	1,984
Due after ten years	286,157
Total	288,141	290,145
Amortized Cost
Due after ten years	123,735
Estimated Fair Value
Due after ten years	123,182
Total	123,182	130,877
Residential Mortgage-backed Securities, Issued by Private Enterprises [Member]
Amortized Cost
Due after ten years	14,456
Estimated Fair Value
Due after ten years	15,083
Total	15,083	17,271
Amortized Cost
Due after ten years	18,875
Estimated Fair Value
Due after ten years	18,621
Total	18,620
Commercial mortgage-backed securities - GSE [Member]
Amortized Cost
Due after five years through 10 years	22,080
Estimated Fair Value
Due after five years through 10 years	22,148
Total	22,148	21,958
Commercial Mortgage-backed Securities, Issued by Private Enterprises [Member]
Amortized Cost
Due after ten years	17,879
Estimated Fair Value
Due after ten years	17,813
Total	17,813	10,215
Amortized Cost
Due after ten years	10,060
Estimated Fair Value
Due after ten years	10,132
Total	10,133	9,998
Corporate notes [Member]
Amortized Cost
Due after one year through five years, amortized cost	30,744
Estimated Fair Value
Due after one year through five years, estimated fair value	30,725
Total	$ 30,725	$ 8,407

[1] Derived from audited consolidated financial statements