UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN REDEEMABLE PREFERRED STOCK AND STOCKHOLDERS' DEFICIT - USD ($) $ in Thousands	Total	Redeemable Convertible Preferred Stock	Common Stock	AOCI Attributable to Parent	Accumulated Deficit
Balance, beginning of period at Dec. 31, 2019		$ 0
Balance, end of period at Mar. 31, 2020		0
Balance, beginning of period at Dec. 31, 2019			$ 547,948	$ (10,017)	$ (539,493)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation			2,395
Warrant issued			653
Dividends and accretion of redemption premium on Redeemable Preferred Stock	$ 0
Net loss	(9,424)				(9,424)
Balance, end of period at Mar. 31, 2020	(7,938)		550,996	(10,017)	(548,917)
Balance, beginning of period at Dec. 31, 2020	24,899	24,899
Increase (Decrease) in Temporary Equity [Roll Forward]
Dividends and accretion of redemption premium on Redeemable Preferred Stock		647
Payment of dividends		(5)
Balance, end of period at Mar. 31, 2021	25,541	$ 25,541
Balance, beginning of period at Dec. 31, 2020	(40,401)		552,852	(8,660)	(584,593)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation			770
Warrant issued			805
Shares issued for Senior Convertible Note interest			788
Junior Convertible Note conversion feature			923
Dividends and accretion of redemption premium on Redeemable Preferred Stock	(647)		(647)
Foreign currency translation loss, net of tax				(658)
Net loss	(6,551)				(6,551)
Balance, end of period at Mar. 31, 2021	$ (44,971)		$ 555,491	$ (9,318)	$ (591,144)