Loans (Narrative) (Details) - USD ($) $ in Thousands		Mar. 31, 2024	Dec. 31, 2023
Accrued interest receivable on loans		$ 23,800	$ 22,900
Total loans	[1]	5,685,232	5,647,706
Nonaccrual loans included in past due loans		5,100	6,900
Nonaccrual loans with no ACL		20,529	23,643
Nonaccrual loans current on payment		25,600	37,700
Residential loans in process of foreclosure		3,200	960
Individually analyzed loans		34,200	34,600
Asset Pledged as Collateral
Total loans		3,400,000	3,400,000
Collateral Dependent Individually Analyzed
Total loans		$ 34,245	$ 34,640

[1] Includes net unamortized loan origination costs of $13.1 million and $13.0 million, respectively, at March 31, 2024 and December 31, 2023 and net unamortized premiums on loans purchased from and serviced by other financial institutions of $273 thousand and $286 thousand, respectively, at March 31, 2024 and December 31, 2023.