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, 2017		4,000	3,000	22,167,000
Beginning 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	35,080				35,080
Exercise of stock options for common stock (in shares)				150,000
Issuance of common stock under 2013 Equity Plan	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)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative-effect adjustment from adoption of ASU 2018-07	0
Stock issued during period (in shares)			(3,000)	782,000
Stock issued during period, value			$ (2,737)		2,737
Share-based compensation expense	$ 23,733				23,733
Exercise of stock options for common stock (in shares)	5,211			5,000
Issuance of common stock under 2013 Equity Plan	$ 31				31
Issuance of common stock under ESPP (in shares)				149,000
Issuance of common stock under ESPP	833				833
Net loss	(116,508)					(116,508)
Ending Balance (in shares) at Dec. 31, 2019		4,000	0	27,195,000
Ending Balance at Dec. 31, 2019	(55,990)	$ 3,906	$ 0	$ 3	$ 977,432	$ (1,037,331)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative-effect adjustment from adoption of ASU 2018-07	$ (160)