Investment and Mortgage-Backed Securities, Available for Sale (Schedule of Held to Maturity Securities, Contractual Maturities) (Details)	3 Months Ended	6 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)
Investments, Debt and Equity Securities [Abstract]
Available-for-sale Securities, Gross Realized Losses	$ 0	$ 0
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Fiscal Year Maturity [Abstract]
Less Than One Year, Amortized Cost	328,603	328,603
One – Five Years, Amortized Cost	15,445,316	15,445,316
Five – Ten Years, Amortized Cost	53,122,450	53,122,450
After Ten Years, Amortized Cost	141,457,081	141,457,081
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis	395,298,490	395,298,490
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
Less Than One Year, Fair Value	328,525	328,525
One – Five Years, Fair Value	15,603,908	15,603,908
Five – Ten Years, Fair Value	53,869,687	53,869,687
After Ten Years, Fair Value	144,275,047	144,275,047
Available-for-sale Securities, Debt Maturities, without Single Maturity Date, Fair Value	$ 401,349,864	$ 401,349,864