Goodwill and other intangibles (Details) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023	Dec. 31, 2022
Finite-Lived Intangible Assets [Line Items]
Goodwill	$ 159,595,000	$ 159,595,000	$ 159,595,000	$ 159,595,000
Other Intangible Assets, Net	4,332,000	5,648,000	4,652,000	5,975,000
Amortization of Intangible Assets	320,000	327,000
Finite-lived Intangible Assets Acquired	14,456,000		14,456,000
Finite-Lived Intangible Assets, Amortization Expense, Next Twelve Months	894,000
Finite-Lived Intangible Assets, Amortization Expense, Year Two	1,042,000
Finite-Lived Intangible Assets, Amortization Expense, Year Three	887,000
Finite-Lived Intangible Assets, Amortization Expense, Year Four	754,000
Finite-Lived Intangible Assets, Amortization Expense, Year Five	618,000
Intangible Assets, Net (Including Goodwill)	163,927,000	$ 165,243,000	164,247,000	$ 165,570,000
Core Deposits [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Accumulated Amortization	$ 10,124,000		$ 9,804,000