Condensed Consolidated Balance Sheets (unaudited) - USD ($)	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 12,769,293	$ 13,176,452
Short term investments	69,089,724	67,707,143
Accounts receivable	17,768,757	16,518,687
Deferred royalty buy-down	0	184,931
Prepaid expenses and other current assets	836,708	646,749
Prepaid income taxes	951,776	0
Total current assets	101,416,258	98,233,962
Long-term investments	16,492,528	1,099,834
Deferred tax assets, net	0	313,768
Patent costs, net	562,503	444,478
Total assets	118,471,289	100,092,042
Current liabilities:
Accounts payable and accrued expenses	877,228	1,798,588
Income tax payable	0	704,934
Total current liabilities	877,228	2,503,522
Deferred tax liability, net	593,059	0
Commitments and Contingencies
Stockholders' equity:
Common stock, $.001 par value; 10,000,000 shares authorized 7,811,230 and 7,738,167 shares issued, 7,342,756 and 7,275,902 shares outstanding as of September 30, 2019 and December 31, 2018, respectively	7,811	7,738
Additional paid-in capital	38,956,156	36,302,446
Retained earnings	89,292,707	72,176,719
Treasury stock, 468,474 and 462,265 shares at cost as of September 30, 2019 and December 31, 2018, respectively	(11,255,672)	(10,898,383)
Total stockholders' equity	117,001,002	97,588,520
Total liabilities and stockholders' equity	118,471,289	100,092,042
Series A Preferred Stock [Member]
Stockholders' equity:
Series A Preferred stock, $.50 par value, 700,000 shares authorized; none outstanding	$ 0	$ 0