Investment Securities (Details 2)	6 Months Ended	12 Months Ended
	Jun. 30, 2018 USD ($) Number	Dec. 31, 2017 USD ($) Number
Less than 12 Months
Number of positions | Number	36	40
Fair Value	$ 89,069,319	$ 96,650,130
Gross Unrealized Loss	$ (2,372,195)	$ (1,008,317)
12 months or Longer
Number of positions | Number	22	32
Fair value	$ 17,408,232	$ 21,337,625
Gross Unrealized Losses	$ (983,871)	$ (835,785)
Total
Number of positions | Number	58	72
Fair value	$ 106,477,551	$ 117,987,755
Gross Unrealized Loss	$ (3,356,066)	$ (1,844,102)
U.S. Treasury Notes [Member]
Less than 12 Months
Number of positions | Number	7	8
Fair Value	$ 32,030,197	$ 35,559,845
Gross Unrealized Loss	$ (939,735)	$ (411,145)
Total
Number of positions | Number	7	8
Fair value	$ 32,030,197	$ 35,559,845
Gross Unrealized Loss	$ (939,735)	$ (411,145)
Government-Sponsored Enterprises [Member]
Less than 12 Months
Number of positions | Number	10	12
Fair Value	$ 48,880,925	$ 53,275,064
Gross Unrealized Loss	$ (1,245,021)	$ (462,174)
12 months or Longer
Number of positions | Number	3	3
Fair value	$ 10,040,160	$ 10,281,440
Gross Unrealized Losses	$ (602,871)	$ (425,637)
Total
Number of positions | Number	13	15
Fair value	$ 58,921,085	$ 63,556,504
Gross Unrealized Loss	$ (1,847,892)	$ (887,811)
Municipal Securities [Member]
Less than 12 Months
Number of positions | Number	19	20
Fair Value	$ 8,158,197	$ 7,815,221
Gross Unrealized Loss	$ (187,439)	$ (134,998)
12 months or Longer
Number of positions | Number	19	29
Fair value	$ 7,368,072	$ 11,056,185
Gross Unrealized Losses	$ (381,000)	$ (410,148)
Total
Number of positions | Number	38	49
Fair value	$ 15,526,269	$ 18,871,406
Gross Unrealized Loss	$ (568,439)	$ (545,146)