INVESTMENT SECURITIES (Tables)

12 Months Ended

Dec. 31, 2017

Investments, Debt and Equity Securities [Abstract]

Held-to-maturity Securities

	December 31, 2017
	Amortized cost, as adjusted		Gross unrealized holding gains		Gross unrealized holding losses		Estimated fair value
Short-term investments:
Obligations of domestic governmental agencies (maturing between January 2018 and November 2018) (held-to-maturity)	$	27,998,810	$	--	$	35,235	$	27,963,575
Total short-term investment securities	$	27,998,810	$	--	$	35,235	$	27,963,575

	December 31, 2016
	Amortized cost, as adjusted		Gross unrealized holding gains		Gross unrealized holding losses		Estimated fair value
Short-term investments:
Obligations of domestic governmental agencies (maturing between February 2017 and September 2017) (held-to-maturity)	$	19,853,860	$	3,270	$	2,492	$	19,854,638
Total short-term investment securities	$	19,853,860	$	3,270	$	2,492	$	19,854,638