FAIR VALUE MEASUREMENTS (Details) - Recurring [Member] - USD ($)	Dec. 31, 2018	Dec. 31, 2017
Institutional Money Market [Member]
Assets, Fair Value Disclosure [Abstract]
Cash equivalents	$ 6,078,025	$ 3,108,549
Municipal Bonds [Member]
Assets, Fair Value Disclosure [Abstract]
Cash equivalents		800,000
Investments	1,295,350	1,102,650
Corporate Bonds [Member]
Assets, Fair Value Disclosure [Abstract]
Investments	62,420,996	51,299,068
Certificates of Deposit [Member]
Assets, Fair Value Disclosure [Abstract]
Investments	5,090,631	5,318,227
Level 1 [Member] | Institutional Money Market [Member]
Assets, Fair Value Disclosure [Abstract]
Cash equivalents	6,078,025	3,108,549
Level 1 [Member] | Municipal Bonds [Member]
Assets, Fair Value Disclosure [Abstract]
Cash equivalents		0
Investments	0	0
Level 1 [Member] | Corporate Bonds [Member]
Assets, Fair Value Disclosure [Abstract]
Investments	0	0
Level 1 [Member] | Certificates of Deposit [Member]
Assets, Fair Value Disclosure [Abstract]
Investments	5,090,631	5,318,227
Level 2 [Member] | Institutional Money Market [Member]
Assets, Fair Value Disclosure [Abstract]
Cash equivalents	0	0
Level 2 [Member] | Municipal Bonds [Member]
Assets, Fair Value Disclosure [Abstract]
Cash equivalents		800,000
Investments	1,295,350	1,102,650
Level 2 [Member] | Corporate Bonds [Member]
Assets, Fair Value Disclosure [Abstract]
Investments	62,420,996	51,299,068
Level 2 [Member] | Certificates of Deposit [Member]
Assets, Fair Value Disclosure [Abstract]
Investments	0	0
Level 3 [Member] | Institutional Money Market [Member]
Assets, Fair Value Disclosure [Abstract]
Cash equivalents	0	0
Level 3 [Member] | Municipal Bonds [Member]
Assets, Fair Value Disclosure [Abstract]
Cash equivalents		0
Investments	0	0
Level 3 [Member] | Corporate Bonds [Member]
Assets, Fair Value Disclosure [Abstract]
Investments	0	0
Level 3 [Member] | Certificates of Deposit [Member]
Assets, Fair Value Disclosure [Abstract]
Investments	$ 0	$ 0