Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Preferred Stock [Member] Series C-1 Convertible Preferred Stock [Member]	Preferred Stock [Member] Series F Convertible Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]
Beginning Balance (in shares) at Dec. 31, 2015		4,000	3,000	18,244,000
Beginning Balance at Dec. 31, 2015	$ 124,527	$ 3,906	$ 2,737	$ 2	$ 646,408	$ (528,526)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation expense	14,349				14,349
Third party share-based compensation expense	$ 197				197
Exercise of stock options for common stock (in shares)	17,548			17,000
Exercise of stock options for common stock	$ 149				149
Net loss	(78,185)					(78,185)
Ending Balance (in shares) at Dec. 31, 2016		4,000	3,000	18,261,000
Ending Balance at Dec. 31, 2016	61,037	$ 3,906	$ 2,737	$ 2	661,103	(606,711)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued during period (in shares)				3,731,000
Stock issued during period, value	117,480				117,480
Share-based compensation expense	20,776				20,776
Third party share-based compensation expense	$ 1,019				1,019
Exercise of stock options for common stock (in shares)	174,628			175,000
Exercise of stock options for common stock	$ 2,693				2,693
Net loss	(114,803)					(114,803)
Ending Balance (in shares) at Dec. 31, 2017		4,000	3,000	22,167,000
Ending Balance at Dec. 31, 2017	88,202	$ 3,906	$ 2,737	$ 2	803,071	(721,514)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued during period (in shares)				3,910,000
Stock issued during period, value	109,809			$ 1	109,808
Share-based compensation expense	34,748				34,748
Third party share-based compensation expense	$ 332				332
Exercise of stock options for common stock (in shares)	106,370			150,000
Exercise of stock options for common stock	$ 1,908				1,908
Issuance of common stock under ESPP (in shares)				32,000
Issuance of common stock under ESPP	391				391
Net loss	(199,469)					(199,469)
Ending Balance (in shares) at Dec. 31, 2018		4,000	3,000	26,259,000
Ending Balance at Dec. 31, 2018	$ 35,921	$ 3,906	$ 2,737	$ 3	$ 950,258	$ (920,983)