Investment and Mortgage-Backed Securities, Held to Maturity (Schedule of investment and mortgage-backed securities held to maturity) (Details) - USD ($)	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2017	Dec. 31, 2016
Schedule of Held-to-maturity Securities [Line Items]
Held to maturity, gross unrealized gains		$ 156,350	$ 63,342
Held-to-maturity Securities, Amortized Cost before Other than Temporary Impairment	$ 27,196,197	27,196,197	25,583,956
Held to maturity, gross unrealized losses		40,207	276,246
Held-to-maturity Securities, Fair Value	27,312,340	27,312,340	25,371,052
Available-for-sale Securities, Gross Realized Losses	0	0
Federal Home Loan Bank Certificates and Obligations (FHLB) [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities	2,000,000	2,000,000
Held to maturity, gross unrealized gains		0
Held to maturity, gross unrealized losses		2,744
Held-to-maturity Securities, Fair Value	1,997,256	1,997,256
Federal Home Loan Mortgage Corporation Certificates and Obligations (FHLMC) [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities	1,997,886	1,997,886
Held to maturity, gross unrealized gains		2,130
Held to maturity, gross unrealized losses		374
Held-to-maturity Securities, Fair Value	1,999,642	1,999,642
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities	23,198,311	23,198,311	25,583,956
Held to maturity, gross unrealized gains		154,220	63,342
Held to maturity, gross unrealized losses		37,089	276,246
Held-to-maturity Securities, Fair Value	$ 23,315,442	$ 23,315,442	$ 25,371,052