SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details)	1 Months Ended	3 Months Ended	12 Months Ended
	Feb. 29, 2016 USD ($)	Mar. 31, 2012 USD ($) Payment	Dec. 31, 2016 USD ($) Customer Quarter Payment Plan $ / shares shares	Dec. 31, 2015 USD ($) Customer $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares
Cash, Cash Equivalents and Investments [Abstract]
Aggregate fair value of investments			$ 48,000,000	$ 31,900,000
Held-to-maturity securities, unrecognized gain			0	0
Held-to-maturity securities, unrecognized loss			0	0
Fair Value Measurements [Abstract]
Amortized premium included in interest income			(610,000)	(316,000)
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity securities, current			44,254,862	28,347,542
Held-to-maturity securities, noncurrent			3,771,380	3,596,541
Concentration of Credit Risk and Major Customers [Abstract]
Accounts receivable			$ 3,810,792	$ 2,547,920
Number of customers | Customer			1	1
Royalty revenue			$ 25,431,012	$ 20,800,757	$ 12,985,370
Royalty / Mark-Up on Cost of Goods Sold [Abstract]
Number of quarters after which revenue is recognized | Quarter			1
Deferred Revenue [Abstract]
Deferred revenue			$ 7,600,000	$ 200,000
Treasury Stock [Abstract]
Treasury stock purchased (in shares) | shares			27,298	40,001	30,848
Average price of share (in dollars per share) | $ / shares			$ 38.41	$ 45.06	$ 26.89
Reimbursable Third Party Development Costs [Abstract]
Accrued patent costs			$ 25,000	$ 20,000
Third Party Royalties [Abstract]
Royalty expenses			1,600,000	1,400,000	$ 800,000
Royalty Buy Down [Abstract]
Initial payment for royalty buy down		$ 1,500,000	$ 600,000
Number of additional cash payments for royalty buy-down | Payment		5
Number of cash payments made for royalty obligation | Payment			4
Deferred costs, amortization period			5 years
Amount amortized related to agreement			$ 1,000,000	600,000	100,000
Deferred royalty buy-down - long term			3,400,000	3,900,000
Income taxes [Abstract]
Unrecognized Tax Benefits			$ 0	0
Share-based Compensation [Abstract]
Number of stock based compensation plans | Plan			1
Net Patent Costs [Abstract]
Net patent costs			$ 258,355	275,206
Estimated aggregate amortization expense [Abstract]
2017			39,000
2018			39,000
2019			39,000
2020			27,000
2021			16,000
Endo [Member]
Concentration of Credit Risk and Major Customers [Abstract]
Accounts receivable			3,800,000	2,500,000
Royalty revenue			26,300,000	22,800,000	14,000,000
Royalty / Mark-Up on Cost of Goods Sold [Abstract]
Deferred revenue on licensing agreements			8,250,000
Proceeds from licensing agreement	$ 8,250,000
Deferred revenue recognized			800,000	0	0
Deferred Revenue [Abstract]
Deferred revenue			7,400,000
Nonrefundable upfront product license fees			53,000
Deferred revenue from foreign tax withholding			100,000
Municipal Bonds [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity securities, current			6,967,954	6,461,216
Held-to-maturity securities, noncurrent			586,074	155,826
Corporate Bonds [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity securities, current			30,418,120	9,882,285
Held-to-maturity securities, noncurrent			2,936,287	1,597,715
Certificates of Deposit [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity securities, current			6,868,788	12,004,041
Held-to-maturity securities, noncurrent			249,019	1,843,000
Patents [Member]
Net Patent Costs [Abstract]
Patents			720,601	697,260
Accumulated amortization			(462,246)	(422,054)
Net patent costs			258,355	275,206
Amortization expense for patents			$ 40,192	$ 45,758	$ 119,920
Patents [Member] | Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization period for intangible assets			3 years
Patents [Member] | Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization period for intangible assets			10 years
Patents [Member] | Endo [Member]
Finite-Lived Intangible Assets [Line Items]
Increase in capitalized patent costs			$ 23,000
Capitalized patents costs reimbursable to customer			$ 25,000