Disclosure About Fair Values of Assets and Liabilities - Measure on recurring basis (Details) - USD ($)	Sep. 30, 2020	Jun. 30, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Mortgage Servicing Rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing rights	$ 1,615,973	$ 1,256,842	$ 1,213,815	$ 1,306,058	$ 1,398,293	$ 1,252,740
Fair Value, Measurements, Recurring [Member] | Mortgage-backed Securities of Government Sponsored Entities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed securities of government sponsored entities	5,539,738		6,733,213
Fair Value, Measurements, Recurring [Member] | Mortgage Servicing Rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing rights	1,615,973		1,213,815
Level 2 | Fair Value, Measurements, Recurring [Member] | Mortgage-backed Securities of Government Sponsored Entities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage-backed securities of government sponsored entities	5,539,738		6,733,213
Level 3 | Fair Value, Measurements, Recurring [Member] | Mortgage Servicing Rights [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage servicing rights	$ 1,615,973		$ 1,213,815