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)		(36,234)
Balance at Jun. 30, 2018		112,081		729,684	(1,273)	(616,330)
Balance (in shares) at Jun. 30, 2018			92,503,273
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
Balance at Mar. 31, 2018		106,118		708,266	(1,328)	(600,820)
Balance (in shares) at Mar. 31, 2018			90,398,901
Share-based compensation to employees		10,206		10,206
Proceeds from issuance of shares		938		938
Proceeds from issuance of shares (in shares)			54,386
Exercise of options and warrants and vested RSUs		10,274		10,274
Exercise of options and warrants and vested RSUs (in shares)			2,049,986
Other comprehensive income (loss), net of tax benefit		55			55
Net income (loss)		(15,510)				(15,510)
Balance at Jun. 30, 2018		112,081		729,684	(1,273)	(616,330)
Balance (in shares) at Jun. 30, 2018			92,503,273
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
Balance at Dec. 31, 2018		112,259		757,314	(1,400)	(643,655)
Balance (in shares) at Dec. 31, 2018			93,254,185
Net income (loss)		(13,420)
Balance at Jun. 30, 2019		158,906		818,338	(2,357)	(657,075)
Balance (in shares) at Jun. 30, 2019			97,858,876
Balance at Mar. 31, 2019		126,394		783,941	(1,742)	(655,805)
Balance (in shares) at Mar. 31, 2019			95,692,797
Share-based compensation to employees		13,732		13,732
Proceeds from issuance of shares		1,208		1,208
Proceeds from issuance of shares (in shares)			43,421
Exercise of options and warrants and vested RSUs		19,457		19,457
Exercise of options and warrants and vested RSUs (in shares)			2,122,658
Other comprehensive income (loss), net of tax benefit		(615)			(615)
Net income (loss)		(1,270)				(1,270)
Balance at Jun. 30, 2019		$ 158,906		$ 818,338	$ (2,357)	$ (657,075)
Balance (in shares) at Jun. 30, 2019			97,858,876

[1] Resulting from the adoption of ASC 606.