Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Gain (Loss)	Treasury Stock
Balance, shares at Dec. 31, 2015		103,860
Balance, value at Dec. 31, 2015	$ 285,850	$ 104	$ 1,397,646	$ (1,108,934)	$ (219)	$ (2,747)
Issuance of common stock to designees of Symphony Icon Holdings LLC, value	0
Stock-based compensation	1,835	$ 0	1,835	0	0	0
Issuance of common stock under Equity Incentive Plans, shares		223
Issuance of common stock under Equity Incentive Plans, value	184	$ 0	184	0	0	0
Repurchase of common stock	(621)	0	0	0	0	(621)
Net loss	(34,883)	0	0	(34,883)	0	0
Unrealized gain (loss) on investments	516	$ 0	0	0	516	0
Balance, shares at Mar. 31, 2016		104,083
Balance, value at Mar. 31, 2016	252,881	$ 104	1,399,665	(1,143,817)	297	(3,368)
Balance, shares at Dec. 31, 2016		104,582
Balance, value at Dec. 31, 2016	157,401	$ 105	1,411,222	(1,250,363)	(195)	(3,368)
Cumulative effect of change in accounting principle	0	$ 0	1,991	(1,991)	0	0
Issuance of common stock to designees of Symphony Icon Holdings LLC, shares		660
Issuance of common stock to designees of Symphony Icon Holdings LLC, value	10,499	$ 0	10,499	0	0	0
Stock-based compensation	2,231	$ 0	2,231	0	0	0
Issuance of common stock under Equity Incentive Plans, shares		96
Issuance of common stock under Equity Incentive Plans, value	1,111	$ 0	1,111	0	0	0
Issuance of treasury stock	0	0	(3,143)	0	0	3,143
Repurchase of common stock	(1,679)	0	0	0	0	(1,679)
Net loss	(34,891)	0	0	(34,891)	0	0
Unrealized gain (loss) on investments	(69)	$ 0	0	0	(69)	0
Balance, shares at Mar. 31, 2017		105,338
Balance, value at Mar. 31, 2017	$ 134,603	$ 105	$ 1,423,911	$ (1,287,245)	$ (264)	$ (1,904)