Shareholders' Equity (Regulatory Captial Requirements) (Details) $ in Thousands		Mar. 31, 2026 USD ($)	Dec. 31, 2025 USD ($)
Corporation
Total Capital (to Risk-Weighted Assets):
Total Capital		$ 622,030	$ 615,600
Total Capital to Risk-Weighted Assets		0.1338	0.1295
Total Capital for Capital Adequacy Purposes		$ 372,027	$ 380,342
Total Capital for Capital Adequacy Purposes to Risk-Weighted Assets		0.0800	0.0800
Tier 1 Capital (to Risk-Weighted Assets):
Tier 1 Capital		$ 579,664	$ 577,224
Tier 1 Capital to Risk Weighted-Assets		0.1246	0.1214
Tier 1 Capital Required For Capital Adequacy Purposes		$ 279,020	$ 285,256
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		$ 557,667	$ 555,227
Common Equity Tier 1 Capital to Risk-Weighted Assets		0.1199	0.1168
Common Equity Tier 1 Capital Required for Capital Adequacy		$ 209,265	$ 213,942
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]	$ 579,664	$ 577,224
Tier 1 Leverage Capital to Average Assets	[1]	0.0880	0.0865
Tier 1 Leverage Capital Required for Capital Adequacy Purposes	[1]	$ 263,555	$ 267,046
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		$ 614,658	$ 607,862
Total Capital to Risk-Weighted Assets		0.1322	0.1279
Total Capital for Capital Adequacy Purposes		$ 371,824	$ 380,144
Total Capital for Capital Adequacy Purposes to Risk-Weighted Assets		0.0800	0.0800
Total Capital To Be Well Capitalized		$ 464,781	$ 475,180
Total Capital To Be Well Capitalized to Risk Weighted-Assets		0.1000	0.1000
Tier 1 Capital (to Risk-Weighted Assets):
Tier 1 Capital		$ 572,292	$ 569,486
Tier 1 Capital to Risk Weighted-Assets		0.1231	0.1198
Tier 1 Capital Required For Capital Adequacy Purposes		$ 278,868	$ 285,108
Tier 1 Capital Required for Capital Adequacy Purposes to Risk Weighted-Assets		0.0600	0.0600
Tier 1 Capital Required To Be Well Capitalized		$ 371,824	$ 380,144
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		$ 572,292	$ 569,486
Common Equity Tier 1 Capital to Risk-Weighted Assets		0.1231	0.1198
Common Equity Tier 1 Capital Required for Capital Adequacy		$ 209,151	$ 213,831
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		$ 302,107	$ 308,867
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]	$ 572,292	$ 569,486
Tier 1 Leverage Capital to Average Assets	[1]	0.0869	0.0853
Tier 1 Leverage Capital Required for Capital Adequacy Purposes	[1]	$ 263,425	$ 266,921
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]	$ 329,281	$ 333,651
Tier 1 Leverage Capital Required To Be Well Capitalized to Average Assets	[1]	0.0500	0.0500

[1] Leverage ratio.