CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues:
Revenue	$ 35,953	$ 110,979	$ 35,013
Costs and expenses:
Cost of revenues	170	218	197
Sales and marketing	6,426	6,118	13,516
Research and development	7,840	9,727	11,759
General and administrative	42,968	41,815	53,343
Restructuring costs	0	0	1,620
Total costs and expenses	57,404	57,878	80,435
Operating income (loss)	(21,451)	53,101	(45,422)
Interest and other income	1,787	1,832	337
Other income (expense), net	91	(198)	274
Income (loss) before provision for income taxes	(19,573)	54,735	(44,811)
Provision for income taxes	(471)	(392)	(480)
Net income (loss)	$ (20,044)	$ 54,343	$ (45,291)
Basic net income (loss) per share (in dollars per share)	$ (0.64)	$ 1.78	$ (1.55)
Shares used in calculating basic net income (loss) per share (in shares)	31,529	30,459	29,179
Diluted net income (loss) per share (in dollars per share)	$ (0.64)	$ 1.73	$ (1.55)
Shares used in calculating diluted net income (loss) per share (in shares)	31,529	31,407	29,179
Other comprehensive income (loss), net of tax
Change in unrealized gains (losses) on short-term investments	$ 8	$ 17	$ (16)
Total other comprehensive income (loss)	8	17	(16)
Total comprehensive income (loss)	(20,036)	54,360	(45,307)
Royalty and license
Revenues:
Revenue	35,643	110,557	34,089
Development, services, and other
Revenues:
Revenue	$ 310	$ 422	$ 924