Shareholders' Equity (Regulatory Captial Requirements) (Details) $ in Thousands		Mar. 31, 2025 USD ($)	Dec. 31, 2024 USD ($)
Corporation
Total Capital (to Risk-Weighted Assets):
Total Capital		$ 619,238	$ 617,762
Total Capital to Risk-Weighted Assets		0.1313	0.1247
Total Capital for Capital Adequacy Purposes		$ 377,420	$ 396,309
Total Capital for Capital Adequacy Purposes to Risk-Weighted Assets		0.0800	0.0800
Tier 1 Capital (to Risk-Weighted Assets):
Tier 1 Capital		$ 576,942	$ 576,731
Tier 1 Capital to Risk Weighted-Assets		0.1223	0.1164
Tier 1 Capital Required For Capital Adequacy Purposes		$ 283,065	$ 297,232
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		$ 554,945	$ 554,734
Common Equity Tier 1 Capital to Risk-Weighted Assets		0.1176	0.1120
Common Equity Tier 1 Capital Required for Capital Adequacy		$ 212,299	$ 222,924
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]	$ 576,942	$ 576,731
Tier 1 Leverage Capital to Average Assets	[1]	0.0845	0.0813
Tier 1 Leverage Capital Required for Capital Adequacy Purposes	[1]	$ 273,007	$ 283,730
Tier 1 Leverage Capital Required for Capital Adequacy Purposes to Average Assets	[1]	0.0400	0.0400
Bank
Total Capital (to Risk-Weighted Assets):
Total Capital		$ 613,684	$ 612,603
Total Capital to Risk-Weighted Assets		0.1301	0.1237
Total Capital for Capital Adequacy Purposes		$ 377,218	$ 396,150
Total Capital for Capital Adequacy Purposes to Risk-Weighted Assets		0.0800	0.0800
Total Capital To Be Well Capitalized		$ 471,523	$ 495,187
Total Capital To Be Well Capitalized to Risk Weighted-Assets		0.1000	0.1000
Tier 1 Capital (to Risk-Weighted Assets):
Tier 1 Capital		$ 571,388	$ 571,572
Tier 1 Capital to Risk Weighted-Assets		0.1212	0.1154
Tier 1 Capital Required For Capital Adequacy Purposes		$ 282,914	$ 297,112
Tier 1 Capital Required for Capital Adequacy Purposes to Risk Weighted-Assets		0.0600	0.0600
Tier 1 Capital Required To Be Well Capitalized		$ 377,218	$ 396,150
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		$ 571,388	$ 571,572
Common Equity Tier 1 Capital to Risk-Weighted Assets		0.1212	0.1154
Common Equity Tier 1 Capital Required for Capital Adequacy		$ 212,185	$ 222,834
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		$ 306,490	$ 321,872
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]	$ 571,388	$ 571,572
Tier 1 Leverage Capital to Average Assets	[1]	0.0838	0.0806
Tier 1 Leverage Capital Required for Capital Adequacy Purposes	[1]	$ 272,892	$ 283,628
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]	$ 341,115	$ 354,536
Tier 1 Leverage Capital Required To Be Well Capitalized to Average Assets	[1]	0.0500	0.0500

[1] Leverage ratio.