Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Conversion of Series F Preferred Stock into Common Stock [Member]	Conversion Of Series C-1 And D-1 Preferred Stock Into Common Stock [Member]	Preferred Stock [Member] Series C-1 Convertible Preferred Stock [Member]	Preferred Stock [Member] Series C-1 Convertible Preferred Stock [Member] Conversion Of Series C-1 And D-1 Preferred Stock Into Common Stock [Member]	Preferred Stock [Member] Series F Convertible Preferred Stock [Member]	Preferred Stock [Member] Series F Convertible Preferred Stock [Member] Conversion of Series F Preferred Stock into Common Stock [Member]	Common Stock [Member]	Common Stock [Member] Conversion of Series F Preferred Stock into Common Stock [Member]	Common Stock [Member] Conversion Of Series C-1 And D-1 Preferred Stock Into Common Stock [Member]	Common Stock [Member] Series C-1 Convertible Preferred Stock [Member]	Common Stock [Member] Series F Convertible Preferred Stock [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] Conversion of Series F Preferred Stock into Common Stock [Member]	Additional Paid-in Capital [Member] Conversion Of Series C-1 And D-1 Preferred Stock Into Common Stock [Member]	Retained Earnings [Member]
Beginning Balance (in shares) at Dec. 31, 2013				7,000		3,000		4,404,000
Beginning Balance at Dec. 31, 2013	$ 7,653			$ 7,016		$ 3,250		$ 4					$ 462,684			$ (465,301)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adjustment for reverse stock split	0							$ (4)					4
Stock issued during period (in shares)								5,395,000			5,341,670	129,105
Stock issued during period, value	53,063							$ 1					53,062
Conversion of Convertible Preferred Stock into common stock (in shares)					3,000				129,000	5,342,000
Conversion of Convertible Preferred Stock into common stock		$ 0	$ 0		$ (3,099)		$ (452)			$ 1				$ 452	$ 3,098
Share-based compensation expense	8,992												8,992
Third party share-based compensation expense	63												63
Common stock issued for services (in shares)								3,000
Common stock issued for services	$ 25												25
Exercise of stock options for common stock (in shares)	0
Restricted stock awards canceled (in shares)								(47,000)
Restricted stock awards canceled	$ (27)												(27)
Net loss	(21,313)															(21,313)
Ending Balance (in shares) at Dec. 31, 2014				4,000		3,000		15,226,000
Ending Balance at Dec. 31, 2014	48,456			$ 3,917		$ 2,798		$ 2					528,353			(486,614)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued during period (in shares)								2,933,000			19,134	17,360
Stock issued during period, value	104,596												104,596
Conversion of Convertible Preferred Stock into common stock (in shares)									17,000	19,000
Conversion of Convertible Preferred Stock into common stock		$ 0	$ 0		$ (11)		$ (61)							$ 61	$ 11
Share-based compensation expense	11,551												11,551
Third party share-based compensation expense	$ 1,521												1,521
Exercise of stock options for common stock (in shares)	51,814							45,000
Exercise of stock options for common stock	$ 315												315
Issuance of restricted stock awards (in shares)								4,000
Issuance of restricted stock awards	0
Net loss	(41,912)															(41,912)
Ending Balance (in shares) at Dec. 31, 2015				4,000		3,000		18,244,000
Ending 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)