Securities (Narrative) (Details)	3 Months Ended		6 Months Ended
	Jun. 30, 2024 USD ($) security	Mar. 31, 2024 USD ($)	Jun. 30, 2024 USD ($) security	Jun. 30, 2023 USD ($)	Dec. 31, 2023 USD ($) security
Debt and Equity Securities, FV-NI [Line Items]
Private mortgage-backed security fair value	$ 700,000		$ 700,000
Debt securities, available-for-sale and held-to-maturity, number of positions | security	621		621		657
Number of securities held in an unrealized loss position | security	600		600		632
Investment securities, pledged as collateral for public deposits	$ 874,100,000		$ 874,100,000		$ 971,300,000
Gain on sale of VISA B shares			4,500,000
Proceeds from sales of securities available for sale	138,200,000		138,182,000	$ 111,862,000
Securities losses, net	(4,700,000)		(4,700,000)
Proceeds from maturities, calls and principal repayments of securities available for sale		$ 5,200,000	167,698,000	$ 96,686,000
Losses on calls of securities, net		$ (975,000)
FHLB stock and FRB stock, cost	41,400,000		41,400,000		54,500,000
FHLB, cost	8,500,000		8,500,000		21,700,000
FRB stock	32,900,000		32,900,000		32,800,000
Collateral For FRB Borrowings
Debt and Equity Securities, FV-NI [Line Items]
Investment securities, pledged as collateral for public deposits	627,000,000.0		$ 627,000,000.0		$ 679,000,000.0
Common Class B
Debt and Equity Securities, FV-NI [Line Items]
Gain on sale of VISA B shares	$ 4,500,000