Investment and Mortgage-Backed Securities, Available for Sale (Schedule of Held to Maturity Securities, Contractual Maturities) (Details)	3 Months Ended
Jun. 30, 2018 USD ($)
Investments, Debt and Equity Securities [Abstract]
Available-for-sale Securities, Gross Realized Losses	$ 67,000
Debt Securities, Available-for-sale, Amortized Cost, Fiscal Year Maturity [Abstract]
Less Than One Year, Amortized Cost	181,392
One – Five Years, Amortized Cost	11,200,552
Five – Ten Years, Amortized Cost	41,198,731
After Ten Years, Amortized Cost	138,882,376
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis	363,600,602
Debt Securities, Available-for-sale, Fair Value, Fiscal Year Maturity [Abstract]
Less Than One Year, Fair Value	179,717
One – Five Years, Fair Value	11,175,886
Five – Ten Years, Fair Value	41,093,031
After Ten Years, Fair Value	139,422,797
Debt Securities, Available-for-sale, Maturity, without Single Maturity Date, Fair Value	$ 362,949,939

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
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
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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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