Loans (Narrative) (Details) - USD ($) $ in Thousands		Mar. 31, 2023	Dec. 31, 2022
Accrued interest receivable on loans		$ 19,000	$ 17,600
Total loans	[1]	5,227,969	5,110,139
Nonaccrual loans included in past due loans		5,600	7,200
Nonaccrual loans with no ACL		7,100	6,500
Residential loans in process of foreclosure		763	2,900
Nonaccrual loans current on payment		8,300	5,700
Individually analyzed loans		8,200	10,000
Asset Pledged as Collateral
Total loans		2,600,000	2,400,000
Collateral Dependent Individually Analyzed
Total loans		$ 8,222	$ 8,455

[1] Includes net unamortized loan origination costs of $11.9 million and $11.6 million, respectively, at March 31, 2023 and December 31, 2022 and net unamortized premiums on loans purchased from and serviced by other financial institutions of $310 thousand and $318 thousand, respectively, at March 31, 2023 and December 31, 2022.