Investment and Mortgage-Backed Securities, Available for Sale (Schedule of Temporarily Impaired Securities, Fair Value and Unrealized losses) (Details) - USD ($)	Jun. 30, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Available For Sale, Percent of Unrealized Losses for Securities in a Continuous Loss Position, 12 Months or Longer	28.20%	34.60%
Debt Securities, Available-for-sale, Unrealized Loss Position [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	$ 177,583,096	$ 100,967,638
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	43,720,312	33,529,120
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	221,303,408	134,496,758
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	2,411,230	811,332
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	947,653	429,858
Available-for-sale Securities, Continuous Unrealized Loss Position, Unrealized Losses	3,358,883	1,241,190
Collateralized Loan Obligations [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	9,422,577
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	9,422,577
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	108,760
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Unrealized Losses	108,760
SBA Bonds
Debt Securities, Available-for-sale, Unrealized Loss Position [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	69,699,835	24,433,422
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	5,940,904	5,588,532
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	75,640,739	30,021,954
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	618,720	151,459
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	106,114	38,059
Available-for-sale Securities, Continuous Unrealized Loss Position, Unrealized Losses	724,834	189,518
Tax Exempt Municipal Bonds
Debt Securities, Available-for-sale, Unrealized Loss Position [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	17,010,549	4,406,162
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	4,209,366	4,328,229
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	21,219,915	8,734,391
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	260,006	13,852
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	142,924	42,999
Available-for-sale Securities, Continuous Unrealized Loss Position, Unrealized Losses	402,930	56,851
Taxable Municipal Bonds [Member]
Debt Securities, Available-for-sale, Unrealized Loss Position [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	1,968,670	1,997,130
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,968,670	1,997,130
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	45,931	19,703
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Unrealized Losses	45,931	19,703
Mortgage-Backed Securities
Debt Securities, Available-for-sale, Unrealized Loss Position [Abstract]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	79,481,465	62,574,910
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	33,570,042	23,612,359
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	113,051,507	86,187,269
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Unrealized Losses	1,377,813	624,772
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Unrealized Losses	698,615	348,800
Available-for-sale Securities, Continuous Unrealized Loss Position, Unrealized Losses	$ 2,076,428	$ 973,572