SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES, Revenue Recognition, Impact on Condensed Consolidated Statement of Operations (Details) - USD ($)	3 Months Ended			6 Months Ended
	Jun. 30, 2018		Jun. 30, 2017	Jun. 30, 2018		Jun. 30, 2017
Revenues [Abstract]
Total revenues	$ 7,096,409	[1]	$ 6,535,516	$ 14,185,818	[1]	$ 14,226,135
Costs and expenses [Abstract]
General and administrative	1,985,212	[1]	2,315,283	4,054,845	[1]	4,741,000
Provision for income taxes	954,465	[1]	1,422,829	2,033,039	[1]	3,192,512
Net income	4,300,667	[1]	2,624,091	8,279,271	[1]	5,968,844
Royalties [Member]
Revenues [Abstract]
Total revenues	7,061,139	[1]	$ 6,531,107	14,146,139	[1]	$ 14,217,317
Adjusted / Balances Without Adoption of New Revenue Standard [Member] | ASU 2014-09 [Member]
Revenues [Abstract]
Total revenues	7,300,000			15,000,000
Costs and expenses [Abstract]
General and administrative	2,000,000			4,100,000
Provision for income taxes	1,000,000			2,200,000
Net income	4,500,000			8,900,000
Adjustments / Effect of Change Higher / (Lower) [Member] | ASU 2014-09 [Member]
Revenues [Abstract]
Total revenues	(200,000)			(800,000)
Costs and expenses [Abstract]
General and administrative	0			0
Provision for income taxes	0			(200,000)
Net income	$ (200,000)			$ (600,000)

[1] As of January 1, 2018, the Company adopted the requirements of ASC 606 using the modified retrospective adoption method, and as a result, there is a lack of comparability of certain amounts to the prior periods presented. See Note 2 for additional discussion.