Loans and Allowance for Loan Losses - Major classifications (Details) - USD ($)	9 Months Ended	12 Months Ended
Mar. 31, 2021	Jun. 30, 2020	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019	Jun. 30, 2019
Loans and Leases Receivable Disclosure [Line Items]
Total loans	$ 227,708,066	$ 238,653,905		$ 246,549,421
Less: allowance for loan losses	(1,391,841)	(1,353,427)	$ (1,403,491)	(1,303,434)	$ (1,262,472)	$ (1,293,965)
Total	226,316,225	237,300,478		245,245,987
Deferred loan origination fees	110,000	184,000
Construction, Land, Development
Loans and Leases Receivable Disclosure [Line Items]
Total loans	2,095,640	4,598,382		4,762,278
Less: allowance for loan losses	(7,335)	(13,795)	(11,248)	(14,287)	(10,863)	(4,319)
Total	2,088,305	4,584,587		4,747,991
1-4 Family Owner Occupied
Loans and Leases Receivable Disclosure [Line Items]
Total loans	77,969,235	100,506,311		109,212,203
Less: allowance for loan losses	(273,132)	(356,434)	(318,772)	(399,104)	(99,975)	(67,593)
Total	77,696,103	100,149,877		108,813,099
1-4 Family Non-Owner Occupied
Loans and Leases Receivable Disclosure [Line Items]
Total loans	22,195,303	21,213,680		20,098,726
Less: allowance for loan losses	(91,560)	(77,220)	(87,352)	(73,159)	(22,168)	(26,630)
Total	22,103,743	21,136,460		20,025,567
Multifamily
Loans and Leases Receivable Disclosure [Line Items]
Total loans	91,898,930	76,444,156		78,150,768
Less: allowance for loan losses	(436,520)	(286,665)	(399,465)	(312,603)	(116,900)	(109,870)
Total	91,462,410	76,157,491		77,838,165
Commercial Owner Occupied
Loans and Leases Receivable Disclosure [Line Items]
Total loans	6,355,215	6,733,183		6,843,419
Less: allowance for loan losses	(101,093)	(95,711)	(86,450)	(94,144)	(80,090)	(61,193)
Total	6,254,122	6,637,472		6,749,275
Commercial Non-Owner Occupied
Loans and Leases Receivable Disclosure [Line Items]
Total loans	19,458,183	20,237,534		18,744,604
Less: allowance for loan losses	(316,196)	(312,670)	(340,647)	(267,111)	(809,722)	(738,366)
Total	19,141,987	19,924,864		18,477,493
Consumer and Installment Loan
Loans and Leases Receivable Disclosure [Line Items]
Total loans	7,735,560	8,920,659		8,737,423
Less: allowance for loan losses	(86,301)	(97,312)	$ (86,852)	(98,431)	$ (86,014)	$ (70,058)
Total	$ 7,649,259	$ 8,823,347		$ 8,638,992

The net increase(decrease) in interest income during the period representing the allocation of deferred loan origination fees less deferred loan origination costs using the effective interest method over the term of the debt arrangement to which they pertain taking into account the effect of prepayments.

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Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements and loans held for sale.

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