Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Cumulative Effect, Period of Adoption, Adjustment [Member] Common Stock [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Preferred Stock [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Treasury Stock [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Additional Paid-in Capital [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Retained Earnings [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] AOCI Attributable to Parent [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member]	Public Offering [Member] Common Stock [Member]	Public Offering [Member] Preferred Stock [Member]	Public Offering [Member] Treasury Stock [Member]	Public Offering [Member] Additional Paid-in Capital [Member]	Public Offering [Member] Retained Earnings [Member]	Public Offering [Member] AOCI Attributable to Parent [Member]	Public Offering [Member]	Common Stock [Member]	Preferred Stock [Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Total
Balance (in shares) at Dec. 31, 2018															16,642	0	0
Balance at Dec. 31, 2018	$ 0	$ 0	$ 0	$ (7)	$ 7	$ 0	$ 0								$ 17	$ 0	$ 0	$ 676,572	$ (509,406)	$ 1,338	$ 168,521
Stock-based compensation															$ 0	$ 0	$ 0	11,508	0	0	11,508
Issuance of stock (in shares)															3,571	0	0
Issuance of stock															$ 4	$ 0	$ 0	25,773	0	0	25,777
Issuance of common stock consideration of MST (in shares)															370	0	0
Issuance of common stock consideration of MST															$ 0	$ 0	$ 0	6,599	0	0	6,599
Exercise of stock options and warrants (in shares)															38	0	0
Exercise of stock options and warrants															$ 0	$ 0	$ 0	538	0	0	538
Award of restricted stock units (in shares)															70	0	0
Award of restricted stock units															$ 0	$ 0	$ 0	0	0	0	0
Return of common stock to pay withholding taxes on restricted stock (in shares)															0	0	15
Return of common stock to pay withholding taxes on restricted stock															$ 0	$ 0	$ 0	(499)	0	0	(499)
Cancellation of treasury stock (in shares)															0	0	(15)
Cancellation of treasury stock															$ 0	$ 0	$ 0	0	0	0	0
Other comprehensive income (loss)															0	0	0	0	0	(2,708)	(2,708)
Net loss															$ 0	$ 0	$ 0	0	(154,201)	0	(154,201)
Balance (in shares) at Dec. 31, 2019															20,691	0	0
Balance at Dec. 31, 2019															$ 21	$ 0	$ 0	720,484	(663,600)	(1,370)	55,535
Stock-based compensation																		7,911			7,911
Issuance of stock (in shares)								14,122	7,937	0					66,241	0	0
Issuance of stock								$ 14	$ 79	$ 0	$ 13,384	$ 0	$ 0	$ 13,477	$ 66	$ 0	$ 0	33,780	0	0	33,846
Exercise of stock options and warrants (in shares)															4,913	0	0
Exercise of stock options and warrants															$ 5	$ 0	$ 0	3,335	0	0	3,340
Award of restricted stock units (in shares)															286	0	0
Award of restricted stock units															$ 0	$ 0	$ 0	0	0	0	0
Return of common stock to pay withholding taxes on restricted stock (in shares)															0	0	28
Return of common stock to pay withholding taxes on restricted stock															$ 0	$ 0	$ 0	(36)	0	0	(36)
Cancellation of treasury stock (in shares)															0	0	(28)
Cancellation of treasury stock															$ 0	$ 0	$ 0	0	0	0	0
Other comprehensive income (loss)															0	0	0	0	0	4,338	4,338
Net loss															$ 0	$ 0	$ 0	0	(59,312)	0	(59,312)
Conversion of preferred stock to common stock (in shares)															7,937	(7,937)	0
Conversion of preferred stock to common stock															$ 8	$ (79)	$ 0	71	0	0	0
Exchange of shares for Series B Warrants (in shares)															2,041	0	0
Exchange of shares for Series B Warrants															$ 2	$ 0	$ 0	2,468	0	0	2,470
Balance (in shares) at Dec. 31, 2020															116,231	0	0
Balance at Dec. 31, 2020															$ 116	$ 0	$ 0	$ 781,397	$ (722,912)	$ 2,968	$ 61,569