Consolidated Statements of Stockholders' Equity (Deficit) - USD ($) $ in Thousands	Total	ABG [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Additional Paid-In Capital [Member] ABG [Member]	Accumulated Other Comprehensive (loss) Income [Member]	Accumulated Deficit [Member]	Accumulated Deficit [Member] ABG [Member]
Beginning Balance at Dec. 31, 2019	$ 285,271		$ 11	$ 705,671		$ 9,719	$ (430,130)
Beginning Balance, Shares at Dec. 31, 2019			102,781,225
Proceeds from ABG Profit Participation Arrangement		$ 1,353			$ 1,353
Write-off of ABG finance receivable					$ 28,900			$ (28,900)
Escrow shares released from downstream merger	(151)			(151)
Escrow shares released shares from downstream merger, shares			(7,659)
Shares issued for common stock at-the-market, net of issuance costs	27,027			27,027
Shares issued for common stock at-the-market, net of issuance costs, shares			2,265,115
Shares issued for investments, shares			6,934
Shares issued under stock-based compensation plans	1,079			1,079
Shares issued under stock-based compensation plans, shares			597,868
Stock-based compensation expenses	7,677			7,677
Shares issued under registered offering, net of issuance costs	19,828		$ 1	19,827
Shares issued under registered offering, net of issuance costs,Shares			7,250,000
Shares issued for exercise of pre-funded warrants	49,054		$ 1	49,053
Shares issued for exercise of pre-funded warrants, shares			11,750,000
Other comprehensive loss	(16,707)					(16,707)
Net loss	(184,123)						(184,123)
Ending Balance at Mar. 31, 2020	190,308		$ 13	840,436		(6,988)	(643,153)
Ending Balance, Shares at Mar. 31, 2020			124,643,483
Beginning Balance at Dec. 31, 2020	373,899		$ 16	1,095,781		8,205	(730,103)
Beginning Balance, Shares at Dec. 31, 2020			158,046,087
Escrow shares released from downstream merger	(135)			(135)
Escrow shares released shares from downstream merger, shares			(6,342)
Shares issued for common stock at-the-market, net of issuance costs	156,030		$ 1	156,029
Shares issued for common stock at-the-market, net of issuance costs, shares			6,254,980
Shares issued under stock-based compensation plans	3,746			3,746
Shares issued under stock-based compensation plans, shares			1,623,255
Stock-based compensation expenses	7,141			7,141
Shares issued for exercise of warrants	337,152		$ 1	337,151
Shares issued for exercise of warrants, shares			12,791,000
Other comprehensive loss	3,753					3,753
Net loss	(340,955)						(340,955)
Ending Balance at Mar. 31, 2021	$ 540,631		$ 18	$ 1,599,713		$ 11,958	$ (1,071,058)
Ending Balance, Shares at Mar. 31, 2021			178,708,980