Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) shares in Thousands, $ in Thousands	Total	Junior Series A Preferred Stock	Common Stock	Additional paid-in capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)
Balance at beginning of period (in shares) at Dec. 31, 2015		0	35,197
Balance at beginning of period at Dec. 31, 2015	$ 59,947	$ 0	$ 35	$ 465,924	$ (405,539)	$ (473)
Increase (Decrease) in Stockholders' Equity
Issuance of common stock under employee stock compensation plans and warrants (in shares)			536
Issuance of common stock under employee stock compensation plans and warrants	6,934		$ 1	6,933
Share-based compensation	0
Excess tax benefit from share-based compensation	0
Net loss	(193,420)				(193,420)
Unrealized gain on available for sale securities, net of tax	261					261
Balance at end of period (in shares) at Dec. 31, 2016		0	35,733
Ending balance at Dec. 31, 2016	(94,618)	$ 0	$ 36	504,517	(598,959)	(212)
Increase (Decrease) in Stockholders' Equity
Issuance of common stock under employee stock compensation plans and warrants (in shares)			377
Issuance of common stock under employee stock compensation plans and warrants	71			71
Share-based compensation	18,171			18,171
Net loss	114,205				114,205
Unrealized gain on available for sale securities, net of tax	212					212
Balance at end of period (in shares) at Dec. 31, 2017		0	36,110
Ending balance at Dec. 31, 2017	38,041	$ 0	$ 36	522,759	(484,754)	0
Increase (Decrease) in Stockholders' Equity
Issuance of common stock under employee stock compensation plans and warrants (in shares)			112
Issuance of common stock under employee stock compensation plans and warrants	65			65
Issuance of common stock related to acquisition (in shares)			5,175
Issuance of common stock related to acquisition	11,694		$ 5	11,689
Share-based compensation	11,072			11,072
Net loss	63,087				63,087
Unrealized gain on available for sale securities, net of tax	0					0
Balance at end of period (in shares) at Dec. 31, 2018		0	41,397
Ending balance at Dec. 31, 2018	$ 123,959	$ 0	$ 41	$ 545,585	$ (421,667)	$ 0