Investment and Mortgage-Backed Securities, Held to Maturity (Schedule of investment and mortgage-backed securities held to maturity) (Details) - USD ($)	6 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, gross unrealized gains	$ 752,263
Debt Securities, Held-to-maturity, Amortized Cost, before Other-than-temporary Impairment	18,090,623
Held to maturity, gross unrealized losses	133,217
Debt Securities, Held-to-maturity, Fair Value	18,709,669	$ 19,205,287
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity	18,090,623
Held to maturity, gross unrealized gains	752,263
Held to maturity, gross unrealized losses	133,217
Debt Securities, Held-to-maturity, Fair Value	$ 18,709,669