Shareholders' Equity (Regulatory Captial Requirements) (Details) $ in Thousands		Mar. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Corporation [Member]
Total Capital (to Risk-Weighted Assets):
Total Capital		$ 614,486	$ 611,220
Total Capital to Risk-Weighted Assets		0.1162	0.1158
Total Capital for Capital Adequacy Purposes		$ 423,075	$ 422,259
Total Capital for Capital Adequacy Purposes to Risk-Weighted Assets		0.0800	0.0800
Tier 1 Capital (to Risk-Weighted Assets):
Tier 1 Capital		$ 573,210	$ 572,960
Tier 1 Capital to Risk Weighted-Assets		0.1084	0.1086
Tier 1 Capital Required For Capital Adequacy Purposes		$ 317,307	$ 316,694
Tier 1 Capital Required for Capital Adequacy Purposes to Risk Weighted-Assets		0.0600	0.0600
Common Equity Tier 1 Capital [Abstract]
Common Equity Tier 1 Capital		$ 551,214	$ 550,964
Common Equity Tier 1 Capital to Risk-Weighted Assets		0.1042	0.1044
Common Equity Tier 1 Capital Required for Capital Adequacy		$ 237,980	$ 237,521
Common Equity Tier 1 Capital for Capital Adequacy Purposes to Risk-Weighted Assets		0.0450	0.0450
Tier 1 Capital (to Average Assets):
Tier 1 Leverage Capital	[1]	$ 573,210	$ 572,960
Tier 1 Leverage Capital to Average Assets	[1]	0.0781	0.0780
Tier 1 Leverage Capital Required for Capital Adequacy Purposes	[1]	$ 293,494	$ 293,837
Tier 1 Leverage Capital Required for Capital Adequacy Purposes to Average Assets	[1]	0.0400	0.0400
Bank [Member]
Total Capital (to Risk-Weighted Assets):
Total Capital		$ 608,485	$ 605,289
Total Capital to Risk-Weighted Assets		0.1151	0.1147
Total Capital for Capital Adequacy Purposes		$ 422,935	$ 422,131
Total Capital for Capital Adequacy Purposes to Risk-Weighted Assets		0.0800	0.0800
Total Capital To Be Well Capitalized		$ 528,669	$ 527,663
Total Capital To Be Well Capitalized to Risk Weighted-Assets		0.1000	0.1000
Tier 1 Capital (to Risk-Weighted Assets):
Tier 1 Capital		$ 567,209	$ 567,029
Tier 1 Capital to Risk Weighted-Assets		0.1073	0.1075
Tier 1 Capital Required For Capital Adequacy Purposes		$ 317,202	$ 316,598
Tier 1 Capital Required for Capital Adequacy Purposes to Risk Weighted-Assets		0.0600	0.0600
Tier 1 Capital Required To Be Well Capitalized		$ 422,935	$ 422,131
Tier 1 Capital Required To Be Well Capitalized to Risk Weighted-Assets		0.0800	0.0800
Common Equity Tier 1 Capital [Abstract]
Common Equity Tier 1 Capital		$ 567,209	$ 567,029
Common Equity Tier 1 Capital to Risk-Weighted Assets		0.1073	0.1075
Common Equity Tier 1 Capital Required for Capital Adequacy		$ 237,901	$ 237,449
Common Equity Tier 1 Capital for Capital Adequacy Purposes to Risk-Weighted Assets		0.0450	0.0450
Common Equity Tier 1 Capital To Be Well Capitalized		$ 343,635	$ 342,981
Common Equity Tier 1 Capital To Be Well Capitalized to Risk-Weighted Assets		0.0650	0.0650
Tier 1 Capital (to Average Assets):
Tier 1 Leverage Capital	[1]	$ 567,209	$ 567,029
Tier 1 Leverage Capital to Average Assets	[1]	0.0773	0.0772
Tier 1 Leverage Capital Required for Capital Adequacy Purposes	[1]	$ 293,398	$ 293,742
Tier 1 Leverage Capital Required for Capital Adequacy Purposes to Average Assets	[1]	0.0400	0.0400
Tier 1 Leverage Capital Required To Be Well Capitalized	[1]	$ 366,747	$ 367,177
Tier 1 Leverage Capital Required To Be Well Capitalized to Average Assets	[1]	0.0500	0.0500

[1] Leverage ratio.