Condensed Consolidated Balance Sheets (unaudited) - USD ($)	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 9,514,493	$ 5,137,875
Short term investments	32,277,242	28,347,542
Accounts receivable	3,787,155	2,547,920
Income tax receivable	928,843	916,843
Deferred royalty buy-down	1,184,225	1,017,981
Prepaid expenses and other current assets	467,130	383,810
Total current assets	48,159,088	38,351,971
Long-term investments	2,471,300	3,596,541
Deferred royalty buy-down - long term, net	2,411,141	2,851,423
Deferred tax assets	3,442,257	622,972
Patent costs, net	270,976	275,206
Total assets	56,754,762	45,698,113
Current liabilities:
Accounts payable and accrued expenses	637,749	611,009
Deferred revenue	1,464,638	149,378
Accrued liabilities of discontinued operations	78,138	78,138
Total current liabilities	2,180,525	838,525
Long-term deferred revenue	6,971,774	49,379
Stockholders' equity:
Series A Preferred stock, $.50 par value, 700,000 shares authorized; none outstanding	0	0
Common stock, $.001 par value; 10,000,000 shares authorized; 7,405,167 and 7,290,167 shares issued, 7,022,964 and 6,918,579 outstanding as of March 31, 2016 and December 31, 2015, respectively	7,405	7,290
Additional paid-in capital	32,159,409	31,797,418
Retained earnings	22,067,734	19,238,610
Treasury stock, 382,203 and 371,588 shares at cost as of March 31, 2016 and December 31, 2015, respectively	(6,632,085)	(6,233,109)
Total stockholders' equity	47,602,463	44,810,209
Total liabilities and stockholders' equity	$ 56,754,762	$ 45,698,113