Consolidated Statements of Stockholders' Equity - 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, 2014		103,663
Balance, value at Dec. 31, 2014	$ 284,018	$ 104	$ 1,390,619	$ (1,104,252)	$ (63)	$ (2,390)
Stock-based compensation	6,843	$ 0	6,843	0	0	0
Issuance of common stock to designees of Symphony Icon Holdings LLC, value	0
Issuance of common stock under Equity Incentive Plans, shares		197
Issuance of common stock under Equity Incentive Plans, value	114	$ 0	114	0	0	0
Repurchase of common stock	(357)	0	0	0	0	357
Consolidated net loss	(4,682)	0	0	(4,682)	0	0
Unrealized gain (loss) on investments	(156)	$ 0	0	0	(156)	0
Balance, shares at Dec. 31, 2015		103,860
Other			70
Balance, value at Dec. 31, 2015	285,850	$ 104	1,397,646	(1,108,934)	(219)	(2,747)
Stock-based compensation	7,452	$ 0	7,452	0	0	0
Issuance of common stock to designees of Symphony Icon Holdings LLC, value	0
Issuance of common stock under Equity Incentive Plans, shares		722
Issuance of common stock under Equity Incentive Plans, value	6,125	$ 1	6,124	0	0	0
Repurchase of common stock	(621)	0	0	0	0	621
Consolidated net loss	(141,429)	0	0	(141,429)	0	0
Unrealized gain (loss) on investments	24	$ 0	0	0	24	0
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)
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	0		1,991	(1,991)	0	0
Stock-based compensation	9,472	$ 0	9,472	0	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		10,499	0	0	0
Issuance of common stock under Equity Incentive Plans, shares		469
Issuance of common stock under Equity Incentive Plans, value	5,486	$ 1	5,485	0	0	0
Issuance of Treasury Stock	0		(3,143)	0	0	(3,143)
Repurchase of common stock	(1,679)	0	0	0	0	(1,679)
Consolidated net loss	(129,050)	0	0	(129,050)	0	0
Unrealized gain (loss) on investments	(27)	$ 0	0	0	(27)	0
Balance, shares at Dec. 31, 2017		105,711
Balance, value at Dec. 31, 2017	$ 52,102	$ 106	$ 1,435,526	$ (1,381,404)	$ (222)	$ (1,904)