Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Cumulative effect of adoption of ASU 2020-06	Common Stock	Additional Paid-in Capital	Additional Paid-in Capital Cumulative effect of adoption of ASU 2020-06	Accumulated Other Comprehensive Income	Accumulated Deficit	Accumulated Deficit Cumulative effect of adoption of ASU 2020-06
Beginning balance at Dec. 31, 2019	$ 71,711		$ 0	$ 1,752,048		$ (27,468)	$ (1,652,869)
Beginning balance, shares at Dec. 31, 2019			163,274,880
Changes in Stockholders' Equity
Stock-based compensation expense	18,366			18,366
Shares issued upon vesting of restricted stock units and for exercises of stock options and warrants	117			117
Shares issued upon vesting of restricted stock units and for exercises of stock options and warrants, shares			877,249
Shares issued for accrued compensation	5,100			5,100
Shares issued for accrued compensation, shares			1,955,405
Shares issued as payment for services	1,006			1,006
Shares issued as payment for services, shares			413,911
Shares issued in private placement	35,000			35,000
Shares issued in private placement, shares			5,972,696
Shares issued upon conversion of long-term debt	56,827			56,827
Shares issued upon conversion of long-term debt, shares			13,051,802
Shares issued in conjunction with settlement agreement	18,103			18,103
Stock issued in conjunction with settlement agreement, shares			2,117,264
Net loss	(170,521)						(170,521)
Release of cumulative translation adjustment to loss from discontinued operations	26,957					26,957
Other comprehensive income (loss)	4,508					4,508
Ending balance at Dec. 31, 2020	$ 67,174		$ 0	1,886,567		3,997	(1,823,390)
Ending balance, shares at Dec. 31, 2020			187,663,207
Changes in Stockholders' Equity
Cumulative effect of adoption of ASC 606 [Extensible List]	Adoption of ASU 2020-06
Stock-based compensation expense	$ 13,904			13,904
Shares issued upon vesting of restricted stock units and for exercises of stock options	608			608
Shares issued upon vesting of restricted stock units and for exercises of stock options, shares			1,751,896
Shares issued as payment for services	577			577
Shares issued as payment for services, shares			74,771
Shares issued in private placement	121,045			121,045
Shares issued in private placement, shares			17,250,000
Net loss	(92,166)						(92,166)
Release of cumulative translation adjustment to loss from discontinued operations	0
Other comprehensive income (loss)	(3,794)					(3,794)
Ending balance at Dec. 31, 2021	$ 107,348	$ (18,196)	$ 0	2,022,701	$ (36,868)	203	(1,915,556)	$ 18,672
Ending balance, shares at Dec. 31, 2021	206,739,874		206,739,874
Changes in Stockholders' Equity
Stock-based compensation expense	$ 10,207			10,207
Shares issued upon vesting of restricted stock units and for exercises of stock options	1			1
Shares issued upon vesting of restricted stock units and for exercises of stock options, shares			354,089
Shares issued for accrued compensation	1,698			1,698
Shares issued for accrued compensation, shares			772,071
Shares issued as payment for services	575			575
Shares issued as payment for services, shares			283,987
Net loss	28,317						28,317
Release of cumulative translation adjustment to loss from discontinued operations	0
Other comprehensive income (loss)	(3,691)					(3,691)
Ending balance at Dec. 31, 2022	$ 126,259		$ 0	$ 1,998,314		$ (3,488)	$ (1,868,567)
Ending balance, shares at Dec. 31, 2022	208,150,021		208,150,021