Investment and Mortgage-Backed Securities, Available for Sale (Schedule of Held to Maturity Securities, Contractual Maturities) (Details) - USD ($)	6 Months Ended
Jun. 30, 2020	Jun. 30, 2019
Investments, Debt and Equity Securities [Abstract]
Available-for-sale Securities, Gross Realized Losses	$ 0	$ 283,000
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]
Less Than One Year, Amortized Cost	78,977
One – Five Years, Amortized Cost	5,183,070
Five – Ten Years, Amortized Cost	67,925,056
After Ten Years, Amortized Cost	157,171,858
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis	456,753,017
Debt Securities, Available-for-sale, Fair Value, Fiscal Year Maturity [Abstract]
Less Than One Year, Fair Value	78,893
One – Five Years, Fair Value	5,225,881
Five – Ten Years, Fair Value	67,955,648
After Ten Years, Fair Value	161,156,516
Debt Securities, Available-for-sale, Maturity, without Single Maturity Date, Fair Value	$ 471,931,623

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in sixth fiscal year through tenth fiscal year following latest fiscal year. Excludes interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

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Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in sixth through tenth fiscal year following latest fiscal year. Excludes interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in second through fifth fiscal year following latest fiscal year. Excludes interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

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Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing in second through fifth fiscal year following latest fiscal year. Excludes interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

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Fair value of investment in debt security, measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), with single maturity date and allocated without single maturity date, maturing after tenth fiscal year following latest fiscal year. Excludes interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

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Fair value of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), maturing in next fiscal year following latest fiscal year. Excludes interim and annual periods when interim period is reported on rolling approach, from latest statement of financial position date.

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