Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Unearned Compensation ESOP [Member]
Beginning Balance at Jun. 30, 2020	$ 47,246			$ 47,236	$ 10
Comprehensive income (loss)	1,399			1,392	7
Ending Balance (in shares) at Jun. 30, 2021		0
Ending Balance at Jun. 30, 2021	48,645	$ 0	$ 0	48,628	17	$ 0
Comprehensive income (loss)	425	0	0	442	(17)	0
Transfer of cash from CFSB to 15 Beach MHC	(100)	$ 0	0	(100)	0	0
Issuance of shares to the mutual holding company (in shares)		3,586,903
Issuance of shares to the mutual holding company	36	$ 36		0	0	0
Issuance of shares in the intial public offering, net of expenses	26,445	$ 28	26,417	0	0	0
Issuance of shares in the intial public offering, net of expenses (in shares)		2,804,306
Issuance and contribution of shares to the Colonial Federal Savings Bank Charitable Foundation, Inc.	1,304	$ 1	1,303	0	0	0
Issuance and contribution of shares to the Colonial Federal Savings Bank Charitable Foundation, Inc. (in shares)		130,433
Purchase of shares by the ESOP	(2,556)	$ 0	0	0	0	(2,556)
ESOP shares earned	51	$ 0	0	0	0	51
Ending Balance (in shares) at Jun. 30, 2022		6,521,642
Ending Balance at Jun. 30, 2022	$ 74,250	$ 65	$ 27,720	$ 48,970	$ 0	$ (2,505)