Loans and Allowance for Credit Losses on Loans, Major Loan Segments and Classes (Details) - USD ($)	Mar. 31, 2024		Dec. 31, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Jun. 30, 2022
Major Loan Segments and Classes [Abstract]
Total gross loans	$ 1,477,635,000	[1],[2]		$ 1,408,866,000
Allowance for credit losses on loans	(20,382,000)		$ (20,309,000)	(21,212,000)	$ (21,155,000)	$ (22,289,000)	$ (22,761,000)
Net loans receivable	1,457,253,000			1,387,654,000
Deferred fees and cost, net	167,000
Accrued interest receivable	6,700,000			5,500
Residential Real Estate [Member] | Residential Real Estate [Member]
Major Loan Segments and Classes [Abstract]
Total gross loans	411,555,000
Allowance for credit losses on loans	(4,138,000)		(4,010,000)	(2,794,000)	(2,638,000)	(2,492,000)
Residential Real Estate [Member] | Real Estate [Member]
Major Loan Segments and Classes [Abstract]
Allowance for credit losses on loans					(2,638,000)		(2,373,000)
Commercial Real Estate [Member] | Real Estate [Member]
Major Loan Segments and Classes [Abstract]
Total gross loans	924,777,000
Allowance for credit losses on loans	(12,496,000)		(12,523,000)	(14,839,000)	(13,572,000)	(15,450,000)	(16,221,000)
Consumer Loan [Member] | Home Equity [Member]
Major Loan Segments and Classes [Abstract]
Total gross loans	27,659,000
Allowance for credit losses on loans	(199,000)		(192,000)	(46,000)	(49,000)	(38,000)	(89,000)
Consumer Loan [Member] | Consumer [Member]
Major Loan Segments and Classes [Abstract]
Total gross loans	4,721,000
Allowance for credit losses on loans	(502,000)		(486,000)	(332,000)	(245,000)	(284,000)	(349,000)
Commercial Loans [Member]
Major Loan Segments and Classes [Abstract]
Total gross loans	108,923,000
Allowance for credit losses on loans	$ (3,047,000)		$ (3,098,000)	$ (3,201,000)	$ (2,800,000)	$ (2,565,000)	$ (2,355,000)

[1] Loan balances exclude accrued interest receivable of $6.7 million at March 31, 2024, which is included in accrued interest receivable in the consolidated statement of financial condition.

[2] Loan balances include net deferred fees/cost of $167 at March 31, 2024.