CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) $ in Thousands		Total	Ordinary Shares	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Retained Earnings (Accumulated Deficit)
Balance at Dec. 31, 2017		$ 113,564		$ 697,165	$ (1,343)	$ (582,258)
Balance (in shares) at Dec. 31, 2017			89,478,032
Share-based compensation to employees		8,520		8,520
Exercise of options and warrants and vested RSUs		2,581		2,581
Exercise of options and warrants and vested RSUs (in shares)			920,869
Cumulative effect adjustment on retained earnings (*)	[1]	2,162				2,162
Other comprehensive income (loss), net of tax benefit		15			15
Net income (loss)		(20,724)				(20,724)
Balance at Mar. 31, 2018		106,118		708,266	(1,328)	(600,820)
Balance (in shares) at Mar. 31, 2018			90,398,901
Balance at Dec. 31, 2017		113,564		697,165	(1,343)	(582,258)
Balance (in shares) at Dec. 31, 2017			89,478,032
Net income (loss)		(63,559)
Balance at Dec. 31, 2018		112,259		757,314	(1,400)	(643,655)
Balance (in shares) at Dec. 31, 2018			93,254,185
Share-based compensation to employees		9,649		9,649
Exercise of options and warrants and vested RSUs		16,978		16,978
Exercise of options and warrants and vested RSUs (in shares)			2,438,612
Other comprehensive income (loss), net of tax benefit		(342)			(342)
Net income (loss)		(12,150)				(12,150)
Balance at Mar. 31, 2019		$ 126,394		$ 783,941	$ (1,742)	$ (655,805)
Balance (in shares) at Mar. 31, 2019			95,692,797

[1] Resulting from the adoption of ASC 606.