Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]	Common Stock Subscribed [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Subscription Receivable [Member]	Treasury Stock [Member]	Total
Balance (in shares) at Dec. 31, 2017	71,325	320					(200)
Balance at Dec. 31, 2017	$ 93		$ 609,829	$ (541,586)	$ (33)	$ (2,109)	$ (2,741)	$ 63,453
Net loss				(13,424)				(13,424)
Foreign currency translation adjustments					(18)			(18)
Stock-based compensation expense			1,048					1,048
Issuance of common stock to former shareholders of MIP, net of payments to advisors (in shares)	1,537	(320)
Issuance of common stock to former shareholders of MIP, net of payments to advisors	$ 2		7,414			2,109		9,525
Cumulative effect of ASU 2014-09 adoption				35				35
Subscription of common stock in connection with at-the-market offering, net of commissions (in shares)		103
Subscription of common stock in connection with at-the-market offering, net of commissions			750			(750)
Balance (in shares) at Mar. 31, 2018	72,862	103					(200)
Balance at Mar. 31, 2018	$ 95		619,041	(554,975)	(51)	(750)	$ (2,741)	60,619
Balance (in shares) at Dec. 31, 2017	71,325	320					(200)
Balance at Dec. 31, 2017	$ 93		609,829	(541,586)	(33)	(2,109)	$ (2,741)	63,453
Net loss								(28,596)
Foreign currency translation adjustments								(56)
Balance (in shares) at Jun. 30, 2018	74,959						(200)
Balance at Jun. 30, 2018	$ 97		635,709	(570,147)	(89)		$ (2,741)	62,829
Balance (in shares) at Mar. 31, 2018	72,862	103					(200)
Balance at Mar. 31, 2018	$ 95		619,041	(554,975)	(51)	(750)	$ (2,741)	60,619
Net loss				(15,172)				(15,172)
Foreign currency translation adjustments					(38)			(38)
Stock-based compensation expense			2,130					2,130
Issuance of common stock to former shareholders of MIP, net of payments to advisors (in shares)	2,097
Issuance of common stock to former shareholders of MIP, net of payments to advisors	$ 2		15,288					15,290
Cumulative effect of ASU 2014-09 adoption
Subscription of common stock in connection with at-the-market offering, net of commissions (in shares)		(103)
Subscription of common stock in connection with at-the-market offering, net of commissions			(750)			750
Balance (in shares) at Jun. 30, 2018	74,959						(200)
Balance at Jun. 30, 2018	$ 97		635,709	(570,147)	(89)		$ (2,741)	62,829
Balance (in shares) at Dec. 31, 2018	84,742						(200)
Balance at Dec. 31, 2018	$ 110		713,019	(609,208)	(105)		$ (2,741)	101,075
Net loss				(18,735)				(18,735)
Foreign currency translation adjustments					(42)			(42)
Stock-based compensation expense			1,077					1,077
Balance (in shares) at Mar. 31, 2019	84,742						(200)
Balance at Mar. 31, 2019	$ 110		714,096	(627,943)	(147)		$ (2,741)	83,375
Balance (in shares) at Dec. 31, 2018	84,742						(200)
Balance at Dec. 31, 2018	$ 110		713,019	(609,208)	(105)		$ (2,741)	101,075
Net loss								(38,435)
Foreign currency translation adjustments								$ 11
Exercise of stock options (in shares)								225
Balance (in shares) at Jun. 30, 2019	86,424	175					(200)
Balance at Jun. 30, 2019	$ 112		724,027	(647,643)	(94)	(933)	$ (2,741)	$ 72,728
Balance (in shares) at Mar. 31, 2019	84,742						(200)
Balance at Mar. 31, 2019	$ 110		714,096	(627,943)	(147)		$ (2,741)	83,375
Net loss				(19,700)				(19,700)
Foreign currency translation adjustments					53			53
Stock-based compensation expense			994					994
Issuance of common stock to former shareholders of MIP, net of payments to advisors (in shares)	1,632
Issuance of common stock to former shareholders of MIP, net of payments to advisors	$ 2		7,737					7,739
Exercise of stock options (in shares)	50
Exercise of stock options			267					267
Subscription receivable in connection with exercise of stock options (in shares)		175
Subscription receivable in connection with exercise of stock options			933			(933)
Balance (in shares) at Jun. 30, 2019	86,424	175					(200)
Balance at Jun. 30, 2019	$ 112		$ 724,027	$ (647,643)	$ (94)	$ (933)	$ (2,741)	$ 72,728