CONDENSED CONSOLIDATED STATEMENTS OF EQUITY (DEFICIT) - USD ($) shares in Thousands, $ in Thousands	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Preferred Series A	Preferred Series A-1	Total
Balance at Dec. 31, 2017	$ 1,349	$ 61,314	$ 271	$ (17,421)	$ 5		$ 45,518
Balance (in shares) at Dec. 31, 2017	13,488				50
Increase (Decrease) in Stockholders' Equity
Issuance of Series A-1 convertible preferred stock		13,305				$ 459	13,764
Issuance of Series A-1 convertible preferred stock (in shares)						4,588
Stock-based compensation		2,121					2,121
Issuance of common stock, net of taxes withheld	$ 64	(492)					(428)
Issuance of common stock, net of taxes withheld (in shares)	644
Foreign currency translation			137				137
Net loss				(20,350)			(20,350)
Balance at Sep. 30, 2018	$ 1,413	76,248	408	(37,771)	$ 5	$ 459	40,762
Balance (in shares) at Sep. 30, 2018	14,132				50	4,588
Balance at Jun. 30, 2018	$ 1,408	75,676	412	(27,190)	$ 5	$ 459	50,770
Balance (in shares) at Jun. 30, 2018	14,079				50	4,588
Increase (Decrease) in Stockholders' Equity
Stock-based compensation		614					614
Issuance of common stock, net of taxes withheld	$ 5	(42)					(37)
Issuance of common stock, net of taxes withheld (in shares)	53
Foreign currency translation			(4)				(4)
Net loss				(10,581)			(10,581)
Balance at Sep. 30, 2018	$ 1,413	76,248	408	(37,771)	$ 5	$ 459	40,762
Balance (in shares) at Sep. 30, 2018	14,132				50	4,588
Balance at Dec. 31, 2018	$ 5,836	218,240	487	(141,186)			$ 83,377
Balance (in shares) at Dec. 31, 2018	58,364						58,364
Increase (Decrease) in Stockholders' Equity
Issuance of common stock, net of taxes withheld	$ 37	(452)					$ (415)
Issuance of common stock, net of taxes withheld (in shares)	374
Stock-based compensation		8,673					8,673
Foreign currency translation			(987)				(987)
Net loss				(170,094)			(170,094)
Balance at Sep. 30, 2019	$ 5,873	226,461	(500)	(311,280)			$ (79,446)
Balance (in shares) at Sep. 30, 2019	58,738						58,738
Balance at Jun. 30, 2019	$ 5,873	223,504	28	(302,301)			$ (72,896)
Balance (in shares) at Jun. 30, 2019	58,734
Increase (Decrease) in Stockholders' Equity
Issuance of common stock, net of taxes withheld (in shares)	4
Stock-based compensation		2,957					2,957
Foreign currency translation			(528)				(528)
Net loss				(8,979)			(8,979)
Balance at Sep. 30, 2019	$ 5,873	$ 226,461	$ (500)	$ (311,280)			$ (79,446)
Balance (in shares) at Sep. 30, 2019	58,738						58,738