Loans and Allowance for Loan Losses - Credit risk profile (Details) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 182,279,150	$ 172,889,042
Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	180,511,803	170,904,121
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	883,419	1,101,481
Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	883,928	883,440
Residential Portfolio Segment [Member] | One- to Four- Family Mortgage Loans Owner Occupied [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	71,019,175	72,697,588
Residential Portfolio Segment [Member] | One- to Four- Family Mortgage Loans Owner Occupied [Member] | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	70,171,068	71,930,902
Residential Portfolio Segment [Member] | One- to Four- Family Mortgage Loans Owner Occupied [Member] | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	111,819	113,516
Residential Portfolio Segment [Member] | One- to Four- Family Mortgage Loans Owner Occupied [Member] | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	736,288	653,170
Residential Portfolio Segment [Member] | One To Four Family Investment [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	12,012,546	12,058,824
Residential Portfolio Segment [Member] | One To Four Family Investment [Member] | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	11,698,826	11,538,993
Residential Portfolio Segment [Member] | One To Four Family Investment [Member] | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	313,720	519,831
Residential Portfolio Segment [Member] | Multi-Family Mortgage Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	48,440,576	41,749,223
Residential Portfolio Segment [Member] | Multi-Family Mortgage Loans [Member] | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	48,440,576	41,669,892
Residential Portfolio Segment [Member] | Multi-Family Mortgage Loans [Member] | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans		79,331
Residential Portfolio Segment [Member] | Real Estate Secured Lines of Credit [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	9,531,404	9,934,387
Residential Portfolio Segment [Member] | Real Estate Secured Lines of Credit [Member] | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	9,383,764	9,783,448
Residential Portfolio Segment [Member] | Real Estate Secured Lines of Credit [Member] | Substandard
Financing Receivable, Recorded Investment [Line Items]
Total loans	147,640	150,939
Non Residential mortgage loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	30,514,717	29,531,917
Non Residential mortgage loans [Member] | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	30,056,837	29,063,783
Non Residential mortgage loans [Member] | Special Mention
Financing Receivable, Recorded Investment [Line Items]
Total loans	457,880	468,134
Commercial real estate portfolio segment [Member] | Construction & Land Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	9,898,208	5,841,415
Commercial real estate portfolio segment [Member] | Construction & Land Loans [Member] | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	9,898,208	5,841,415
Commercial Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	527,645	736,979
Commercial Loans [Member] | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	527,645	736,979
Consumer Loans [Member]
Financing Receivable, Recorded Investment [Line Items]
Total loans	334,879	338,709
Consumer Loans [Member] | Pass
Financing Receivable, Recorded Investment [Line Items]
Total loans	$ 334,879	$ 338,709