Consolidated Statements of Non-Controlling Interest and Stockholders' Equity (Deficit) - USD ($) shares in Thousands, $ in Thousands	Total	Silver Creek Series B Preferred Stock [Member]	Silver Creek Series C Preferred Stock [Member]	Convertible Notes [Member]	Non-Controlling Interest [Member]	Non-Controlling Interest [Member] Silver Creek Series B Preferred Stock [Member]	Non-Controlling Interest [Member] Silver Creek Series C Preferred Stock [Member]	Common Stock [Member]	Common Stock [Member] Convertible Notes [Member]	Additional Paid-In Capital [Member]	Additional Paid-In Capital [Member] Silver Creek Series B Preferred Stock [Member]	Additional Paid-In Capital [Member] Silver Creek Series C Preferred Stock [Member]	Additional Paid-In Capital [Member] Convertible Notes [Member]	Accumulated Other Comprehensive (Loss) Income [Member]	Accumulated Deficit [Member]
Balance at Dec. 31, 2014	$ (102,140)				$ 69			$ 1,067		$ 552,037				$ (74)	$ (655,170)
Balance (in shares) at Dec. 31, 2014								10,670
Exercise of stock options and common stock warrants	10,101							$ 54		10,047
Exercise of stock options and common stock warrants (shares)								536
Issuance of common stock in at the market offering, net of issuance costs	38,560							$ 38		38,522
Issuance of common stock in at the market offering, net of issuance costs (shares)								381
Issuance of preferred stock by Silver Creek Pharmaceuticals, Inc.		$ 1,188				$ 895					$ 1,188
Stock-based compensation	15,351									15,351
Other comprehensive income (loss)	74													$ 74
Loss attributable to non-controlling interest	725				(725)										725
Net income (loss)	(147,787)														(147,787)
Balance at Dec. 31, 2015	(183,928)				239			$ 1,159		617,145					(802,232)
Balance (in shares) at Dec. 31, 2015								11,587
Exercise of stock options	6,442							$ 20		6,422
Exercise of stock options (shares)								196
Issuance of stock due to conversion of convertible notes				$ 100,961					$ 123				$ 100,838
Issuance of stock due to conversion of convertible notes (shares)									1,237
Consideration allocated to reacquisition of conversion feature on extinguishment of convertible notes due 2020	(39,923)									(39,923)
Issuance of preferred stock by Silver Creek Pharmaceuticals, Inc.			$ 2,689				$ (827)					$ 2,689
Stock-based compensation	15,206									15,206
Loss attributable to non-controlling interest	951				(951)										951
Net income (loss)	(153,518)														(153,518)
Balance at Dec. 31, 2016	(251,120)				(1,539)			$ 1,302		702,377					(954,799)
Balance (in shares) at Dec. 31, 2016								13,020
Exercise of stock options	$ 6,689							$ 32		6,657
Exercise of stock options (shares)	323							323
Consideration allocated to reacquisition of conversion feature on extinguishment of convertible notes due 2020	$ (4,481)									(4,481)
Dividend paid	(140,000)									(140,000)
Issuance of preferred stock by Silver Creek Pharmaceuticals, Inc.							$ 847
Stock-based compensation	13,168									13,168
Loss attributable to non-controlling interest	1,160				(1,160)										1,160
Deconsolidation of non-controlling interest	1,852				$ 1,852
Net income (loss)	470,868														470,868
Balance at Dec. 31, 2017	$ 96,284							$ 1,334		$ 577,721					$ (482,771)
Balance (in shares) at Dec. 31, 2017								13,343