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, 2016		0	35,733
Balance at beginning of period 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		$ 0	71
Share-based compensation	18,171			18,171
Net income	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 related to acquisition (in shares)			5,175
Issuance of common stock related to acquisition	11,694		$ 5	11,689
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
Share-based compensation	11,072			11,072
Net income	63,087				63,087
Unrealized gain on available for sale securities, net of tax	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
Increase (Decrease) in Stockholders' Equity
Issuance of common stock and pre-funded warrants, net (in shares)			7,750
Issuance of common stock and pre-funded warrants through underwritten offering, net of issuance costs	42,565		$ 8	42,557
Issuance of common stock related to acquisition (in shares)			75
Issuance of common stock related to acquisition	85				85
Issuance of common stock under employee stock compensation plans and warrants (in shares)			405
Issuance of common stock under employee stock compensation plans and warrants	273		$ 1	272
Share-based compensation	9,180			9,180
Net income	(58,859)				(58,859)
Unrealized gain on available for sale securities, net of tax	0
Balance at end of period (in shares) at Dec. 31, 2019		0	49,627
Ending balance at Dec. 31, 2019	$ 117,203	$ 0	$ 50	$ 597,679	$ (480,526)	$ 0