Loans and Allowance for Credit Losses - Classes of loans (Details) $ in Thousands	6 Months Ended	12 Months Ended
	Dec. 31, 2023 USD ($) loan	Jun. 30, 2023 USD ($) loan	Sep. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)	Sep. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans before fees gross	$ 3,996,636	$ 3,978,393
Loans in Process	(264,483)	(359,196)
Deferred loan fees, net	(263)	(299)
Allowance for credit losses	(50,084)	(47,820)		$ (37,483)	$ (37,418)	$ (33,192)
Total loans	$ 3,681,806	$ 3,571,078
Number of purchased participation loans | loan	74	86
Purchased participation loans	$ 170,600	$ 155,600
Residential Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans before fees gross	1,160,264	1,133,417
Allowance for credit losses	(15,096)	(15,641)	$ (14,846)	(12,499)	(11,937)	(8,908)
Construction Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans before fees gross	508,710	550,052
Allowance for credit losses	(2,864)	(2,664)	$ (2,856)	(2,754)	(2,503)	(2,220)
Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans before fees gross	1,558,600	1,562,379
Allowance for credit losses	(25,177)	(22,838)		(16,806)	(17,886)	(16,838)
Consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans before fees gross	139,163	133,515
Allowance for credit losses	(890)	(909)		(761)	(693)	(710)
Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans before fees gross	629,899	599,030
Allowance for credit losses	$ (6,057)	$ (5,768)		$ (4,663)	$ (4,399)	$ (4,516)