Consolidated Statements of Stockholders' (Deficit) - USD ($) $ in Thousands	Total	TEL AVIV STOCK EXCHANGE	Common Stock	Common Stock TEL AVIV STOCK EXCHANGE	Additional Paid-in Capital	Additional Paid-in Capital TEL AVIV STOCK EXCHANGE	Accumulated Other Comprehensive Income (Loss)	Deficit Accumulated During the Development Stage
Beginning Balance (in shares) at Dec. 31, 2012			286,035,000
Beginning Balance at Dec. 31, 2012	$ (110,679)		$ 2,860		$ 1,991,379		$ (6)	$ (2,104,912)
Exercise of stock options (in shares)			880,000
Exercise of stock options	2,270		$ 9		2,261
Issuance of common shares from the release of restricted stock units (in shares)			1,870,000
Issuance of common shares from the release of restricted stock units	(4,801)		$ 20		(4,821)
Issuance of common shares pursuant to warrant exercises (in shares)			66,353,000
Issuance of common shares pursuant to warrant exercises	172,149		$ 664		171,485
Issuance of common shares pursuant to debt conversions by Deerfield (in Shares)			1,095,000
Issuance of common shares pursuant to debt conversions by Deerfield	5,501		$ 12		5,489
Issuance of common stock	$ 48,888		$ 99		48,789
Issuance of common stock (Shares)			9,824,000
Issuance of common shares pursuant to litigation settlement (in shares)			2,778,000
Issuance of common shares pursuant to litigation settlement			$ 28		(28)
Issuance of common shares under Employee Stock Purchase Plan (in shares)	463,290		557,000
Issuance of common shares under Employee Stock Purchase Plan	$ 1,263		$ 5		1,258
Stock-based compensation	45,186				45,186
Unrealized gain/(loss) on foreign currency translation	2						2
Commitment to deliver common shares pursuant to Deerfield conversion to additional paid-in capital	998				998
Net loss	(191,490)							(191,490)
Ending Balance (in shares) at Dec. 31, 2013			369,392,000
Ending Balance at Dec. 31, 2013	(30,713)		$ 3,697		2,261,996		(4)	(2,296,402)
Exercise of stock options (in shares)			3,251,000
Exercise of stock options	10,978		$ 35		10,943
Issuance of common shares from the release of restricted stock units (in shares)			3,996,000
Issuance of common shares from the release of restricted stock units	(26,908)		$ 38		(26,946)
Issuance of common shares pursuant to warrant exercises (in shares)			11,575,000
Issuance of common shares pursuant to warrant exercises	27,779		$ 115		27,664
Issuance of common shares pursuant to debt conversions by Deerfield (in Shares)			17,521,000
Issuance of common shares pursuant to debt conversions by Deerfield	$ 93,501		$ 174		93,327
Issuance of common shares under Employee Stock Purchase Plan (in shares)	305,076		324,000
Issuance of common shares under Employee Stock Purchase Plan	$ 1,363		$ 2		1,361
Remeasurement of performance based grants pursuant to the modification of terms	22,962				22,962
Stock-based compensation	25,660				25,660
Unrealized gain/(loss) on foreign currency translation	(10)						(10)
Net loss	(198,382)							(198,382)
Ending Balance (in shares) at Dec. 31, 2014			406,059,000
Ending Balance at Dec. 31, 2014	$ (73,770)		$ 4,061		2,416,967		(14)	(2,494,784)
Return of loaned common stock (in shares)	(9,000,000)
Exercise of stock options (in shares)	1,700,964		1,701,000
Exercise of stock options	$ 3,258		$ 17		3,241
Issuance of common shares from the release of restricted stock units (in shares)			720,000
Issuance of common shares from the release of restricted stock units			$ 7		(7)
Restricted stock units taxes paid in cash	(1,856)				(1,856)
Issuance of common shares pursuant to warrant exercises (in shares)			4,216,000
Issuance of common shares pursuant to warrant exercises	10,123		$ 42		10,081
Capital contribution	40				40
Issuance of common shares pursuant to conversions of certain 2015 note holders (in shares)			1,874,000
Issuance of common shares pursuant to conversions of certain 2015 notes	7,926		$ 19		7,907
Issuance of common stock for lender financing fees (in shares)			39,000
Issuance of common stock for lender financing fees	160				160
Discount on notes-for-stock exchange	169				169
Return of loaned common stock			$ (90)		90
Issuance of common stock	$ 27,844	$ 34,710	$ 89	$ 139	27,754	$ 34,571
Issuance of common stock (Shares)			8,940,000	13,853,000
Issuance of common shares under Employee Stock Purchase Plan (in shares)	321,228		269,000
Issuance of common shares under Employee Stock Purchase Plan	$ 887		$ 3		884
Issuance of warrant liability	(202)				(202)
Reclassification of warrant liability to equity	108				108
Stock-based compensation	8,725				8,725
Unrealized gain/(loss) on foreign currency translation	(6)						(6)
Net loss	(368,445)							(368,445)
Ending Balance (in shares) at Dec. 31, 2015			428,671,000
Ending Balance at Dec. 31, 2015	$ (350,329)		$ 4,287		2,508,633		(20)	(2,863,229)
Return of loaned common stock (in shares)	(9,000,000)
Net loss	$ (277,020)
Ending Balance (in shares) at Dec. 31, 2015			428,671,000
Ending Balance at Dec. 31, 2015	$ (350,329)		$ 4,287		$ 2,508,633		$ (20)	$ (2,863,229)
Return of loaned common stock (in shares)			(9,000,000)