Parent Company Financial Information - Schedule of condensed statements of financial condition (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2021
ASSETS
Cash on deposit at the Bank	$ 7,652	$ 8,117
Investment in the Bank	11,561	28,053
Equity securities	1,629	2,258
Other assets	6,198	5,988
TOTAL ASSETS	847,579	879,952
LIABILITIES
Accrued and other liabilities	5,240	5,704
TOTAL LIABILITIES	686,834	687,626
Commitments and contingencies
STOCKHOLDERS' EQUITY
Preferred stock, $0.01 par value, 50,000,000 shares authorized; no shares issued
Common stock, $0.01 par value, 150,000,000 shares authorized; 12,452,921 shares issued and outstanding at June 30, 2023 and 14,896,590 shares issued and outstanding at June 30, 2022	125	149
Additional paid-in capital	134,387	159,546
Unearned common stock held by employee stock ownership plan	(9,194)	(9,599)
Retained earnings	58,805	57,587
Accumulated other comprehensive loss	(23,378)	(15,357)
TOTAL STOCKHOLDERS' EQUITY	160,745	192,326	$ 216,926
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	847,579	879,952
Parent Company
ASSETS
Cash on deposit at the Bank	14,119	41,301
Investment in the Bank	144,004	148,364
Equity securities	1,629	2,258
Other assets	1,190	551
TOTAL ASSETS	160,942	192,474
LIABILITIES
Accrued and other liabilities	197	148
TOTAL LIABILITIES	197	148
Commitments and contingencies
STOCKHOLDERS' EQUITY
TOTAL STOCKHOLDERS' EQUITY	160,745	192,326
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 160,942	$ 192,474