CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenues:
Revenue	$ 30,456	$ 35,953
Costs and expenses:
Cost of revenues	168	170
Sales and marketing	4,999	6,426
Research and development	5,014	7,840
General and administrative	18,055	42,968
Total costs and expenses	28,236	57,404
Operating income (loss)	2,220	(21,451)
Interest and other income	271	1,787
Other income (expense), net	668	91
Income (loss) before benefit from (provision for) income taxes	3,159	(19,573)
Benefit from (provision for) income taxes	2,242	(471)
Net income (loss)	$ 5,401	$ (20,044)
Basic net income (loss) per share (in dollars per share)	$ 0.19	$ (0.64)
Shares used in calculating basic net income (loss) per share (in shares)	28,117	31,529
Diluted net income (loss) per share (in dollars per share)	$ 0.19	$ (0.64)
Shares used in calculating diluted net income (loss) per share (in shares)	28,477	31,529
Other comprehensive income (loss), net of tax
Change in unrealized gains (losses) on short-term investments	$ (2)	$ 8
Total other comprehensive income (loss)	(2)	8
Total comprehensive income (loss)	5,399	(20,036)
Royalty and license
Revenues:
Revenue	30,176	35,643
Development, services, and other
Revenues:
Revenue	$ 280	$ 310