CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Royalties and milestones, net	$ 6,918	$ 8,379
Total revenues	6,918	8,379
Operating expenses:
General and administrative	1,063	1,371
Total operating expenses	1,063	1,371
Operating income and income before income tax expense	5,855	7,008
Income tax expense	6	1,563
Net income	$ 5,849	$ 5,445
Earnings per common share
Basic and diluted	$ 0.13	$ 0.12
Weighted average number of shares
Basic and diluted	44,215	44,215