Shareholders' Equity (Regulatory Captial Requirements) (Details) - USD ($) $ in Thousands		Jun. 30, 2016	Dec. 31, 2015
Corporation [Member]
Total Capital (to Risk-Weighted Assets):
Total Capital		$ 375,899	$ 367,443
Total Capital to Risk-Weighted Assets		12.43%	12.58%
Total Capital for Capital Adequacy Purposes		$ 241,929	$ 233,739
Total Capital for Capital Adequacy Purposes to Risk-Weighted Assets		8.00%	8.00%
Tier 1 Capital (to Risk-Weighted Assets):
Tier 1 Capital		$ 349,891	$ 340,130
Tier 1 Capital to Risk Weighted-Assets		11.57%	11.64%
Tier 1 Capital Required For Capital Adequacy Purposes		$ 181,447	$ 175,304
Tier 1 Capital Required for Capital Adequacy Purposes to Risk Weighted-Assets		6.00%	6.00%
Common Equity Tier 1 Capital [Abstract]
Common Equity Tier 1 Capital		$ 327,892	$ 318,131
Common Equity Tier 1 Capital to Risk Weighted Assets		10.84%	10.89%
Common Equity Tier 1 Capital Required for Capital Adequacy		$ 136,085	$ 131,478
Common Equity Tier 1 Capital for Capital Adequacy to Risk Weighted Assets		4.50%	4.50%
Tier 1 Capital (to Average Assets):
Tier 1 Leverage Capital	[1]	$ 349,891	$ 340,130
Tier 1 Leverage Capital to Average Assets	[1]	9.21%	9.37%
Tier 1 Leverage Capital Required for Capital Adequacy Purposes	[1]	$ 151,949	$ 145,191
Tier 1 Leverage Capital Required for Capital Adequacy Purposes to Average Assets	[1]	4.00%	4.00%
Bank [Member]
Total Capital (to Risk-Weighted Assets):
Total Capital		$ 375,919	$ 366,676
Total Capital to Risk-Weighted Assets		12.43%	12.55%
Total Capital for Capital Adequacy Purposes		$ 241,876	$ 233,676
Total Capital for Capital Adequacy Purposes to Risk-Weighted Assets		8.00%	8.00%
Total Capital To Be Well Capitalized		$ 302,345	$ 292,095
Total Capital To Be Well Capitalized to Risk Weighted-Assets		10.00%	10.00%
Tier 1 Capital (to Risk-Weighted Assets):
Tier 1 Capital		$ 349,911	$ 339,363
Tier 1 Capital to Risk Weighted-Assets		11.57%	11.62%
Tier 1 Capital Required For Capital Adequacy Purposes		$ 181,407	$ 175,257
Tier 1 Capital Required for Capital Adequacy Purposes to Risk Weighted-Assets		6.00%	6.00%
Tier 1 Capital Required To Be Well Capitalized		$ 241,876	$ 233,676
Tier 1 Capital Required To Be Well Capitalized to Risk Weighted-Assets		8.00%	8.00%
Common Equity Tier 1 Capital [Abstract]
Common Equity Tier 1 Capital		$ 349,911	$ 339,363
Common Equity Tier 1 Capital to Risk Weighted Assets		11.57%	11.62%
Common Equity Tier 1 Capital Required for Capital Adequacy		$ 136,055	$ 131,443
Common Equity Tier 1 Capital for Capital Adequacy to Risk Weighted Assets		4.50%	4.50%
Common Equity Tier 1 Capital Required to be Well Capitalized		$ 196,524	$ 189,861
Common Equity Tier 1 Capital Required to be Well Capitalized to Risk Weighted Assets		6.50%	6.50%
Tier 1 Capital (to Average Assets):
Tier 1 Leverage Capital	[1]	$ 349,911	$ 339,363
Tier 1 Leverage Capital to Average Assets	[1]	9.22%	9.36%
Tier 1 Leverage Capital Required for Capital Adequacy Purposes	[1]	$ 151,874	$ 145,103
Tier 1 Leverage Capital Required for Capital Adequacy Purposes to Average Assets	[1]	4.00%	4.00%
Tier 1 Leverage Capital Required To Be Well Capitalized	[1]	$ 189,843	$ 181,378
Tier 1 Leverage Capital Required To Be Well Capitalized to Average Assets	[1]	5.00%	5.00%

[1] Leverage ratio.