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, 2016		104,582
Balance, value at Dec. 31, 2016	$ 167,507	$ 105	$ 1,411,222	$ (1,240,257)	$ (195)	$ (3,368)
Stock-based compensation	9,472	$ 0	9,472	0	0	0
Issuance of common stock to designees of Symphony Icon Holdings LLC, value	10,499
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
Repurchase of common stock	(1,679)	0	0	0	0	1,679
Net loss	(122,993)	0	0	(122,993)	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	68,265	$ 106	1,435,526	(1,365,241)	(222)	(1,904)
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	14,212		0	14,212	0	0
Stock-based compensation	11,696	$ 0	11,696	0	0	0
Symphony Contingent Payment In Cash	0
Issuance of common stock under Equity Incentive Plans, shares		451
Issuance of common stock under Equity Incentive Plans, value	732	$ 0	732	0	0	0
Repurchase of common stock	(972)	0	0	0	0	(972)
Net loss	(120,548)	0	0	(120,548)	0	0
Unrealized gain (loss) on investments	210	$ 0	0	0	210	0
Balance, shares at Dec. 31, 2018		106,162
Balance, value at Dec. 31, 2018	(26,405)	$ 106	1,447,954	(1,471,577)	(12)	(2,876)
Stock-based compensation	14,218	$ 0	14,218	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		517
Issuance of common stock under Equity Incentive Plans, value	0	$ 0	0	0	0	0
Repurchase of common stock	(941)	0	0	0	0	(941)
Net loss	130,133	0	0	130,133	0	0
Unrealized gain (loss) on investments	96	$ 0	0	0	96	0
Balance, shares at Dec. 31, 2019		106,679
Balance, value at Dec. 31, 2019	$ 117,101	$ 106	$ 1,462,172	$ (1,341,444)	$ 84	$ (3,817)