Allowance for Credit Losses (Changes in Allowance for Credit Losses) (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
LOANS
Balance at Beginning of Period	$ 164,300,000	$ 168,000,000.0	$ 168,000,000.0
Charge-Offs	(400,000)	(300,000)	(3,900,000)
Recoveries	300,000	500,000
Net Recoveries (Charge-Offs)	(100,000)	200,000
Provision for Credit Losses	(3,100,000)	(1,100,000)
Balance at End of Period	161,100,000	167,100,000	164,300,000
UNDRAWN LOAN COMMITMENTS AND STANDBY LETTERS OF CREDIT
Balance at Beginning of Period	23,300,000	30,400,000	30,400,000
Charge-Offs	0	0
Recoveries	0	0
Net Recoveries (Charge-Offs)	0	0
Provision for Credit Losses	2,200,000	2,400,000
Balance at End of Period	25,500,000	32,800,000	23,300,000
HELD TO MATURITY DEBT SECURITIES
Balance at Beginning of Period	9,300,000	6,500,000	6,500,000
Charge-Offs	0	0
Recoveries	0	0
Net Recoveries (Charge-Offs)	0	0
Provision for Credit Losses	(1,600,000)	200,000
Balance at End of Period	7,700,000	6,700,000	9,300,000
OTHER FINANCIAL ASSETS
Balance at Beginning of Period	1,400,000	1,000,000.0	1,000,000.0
Charge-Offs	0	0
Recoveries	0	0
Net Recoveries (Charge-Offs)	0	0
Provision for Credit Losses	(500,000)	(300,000)
Balance at End of Period	900,000	700,000	1,400,000
TOTAL
Balance at Beginning of Period	198,300,000	205,900,000	205,900,000
Charge-Offs	(400,000)	(300,000)
Recoveries	300,000	500,000
Net Recoveries (Charge-Offs)	(100,000)	200,000
Provision for credit losses	(3,000,000.0)	1,200,000
Balance at End of Period	195,200,000	207,300,000	198,300,000
TOTAL	195,200,000	207,300,000	$ 198,300,000
Provision for credit losses	$ 0	$ (200,000)