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)
Beginning balance at Dec. 31, 2017		$ 113,564		$ 697,165	$ (1,343)	$ (582,258)
Beginning balance (in shares) at Dec. 31, 2017			89,478,032
Increase (Decrease) in Stockholders' Equity [Roll Forward]
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)
Ending balance at Mar. 31, 2018		106,118		708,266	(1,328)	(600,820)
Ending balance (in shares) at Mar. 31, 2018			90,398,901
Beginning balance at Dec. 31, 2017		113,564		697,165	(1,343)	(582,258)
Beginning balance (in shares) at Dec. 31, 2017			89,478,032
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		(47,928)
Ending balance at Sep. 30, 2018		114,936		744,087	(1,127)	(628,024)
Ending balance (in shares) at Sep. 30, 2018			93,007,844
Beginning balance at Dec. 31, 2017		113,564		697,165	(1,343)	(582,258)
Beginning balance (in shares) at Dec. 31, 2017			89,478,032
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		(63,559)
Ending balance at Dec. 31, 2018		112,259		757,314	(1,400)	(643,655)
Ending balance (in shares) at Dec. 31, 2018			93,254,185
Beginning balance at Mar. 31, 2018		106,118		708,266	(1,328)	(600,820)
Beginning balance (in shares) at Mar. 31, 2018			90,398,901
Increase (Decrease) in Stockholders' Equity [Roll Forward]
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)
Ending balance at Jun. 30, 2018		112,081		729,684	(1,273)	(616,330)
Ending balance (in shares) at Jun. 30, 2018			92,503,273
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation to employees		10,479		10,479
Exercise of options and warrants and vested RSUs		3,924		3,924
Exercise of options and warrants and vested RSUs (in shares)			504,571
Other comprehensive income (loss), net of tax benefit		146			146
Net income (loss)		(11,694)				(11,694)
Ending balance at Sep. 30, 2018		114,936		744,087	(1,127)	(628,024)
Ending balance (in shares) at Sep. 30, 2018			93,007,844
Beginning balance at Dec. 31, 2018		112,259		757,314	(1,400)	(643,655)
Beginning balance (in shares) at Dec. 31, 2018			93,254,185
Increase (Decrease) in Stockholders' Equity [Roll Forward]
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)
Ending balance at Mar. 31, 2019		126,394		783,941	(1,742)	(655,805)
Ending balance (in shares) at Mar. 31, 2019			95,692,797
Beginning balance at Dec. 31, 2018		112,259		757,314	(1,400)	(643,655)
Beginning balance (in shares) at Dec. 31, 2018			93,254,185
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		(11,490)
Ending balance at Sep. 30, 2019		190,365		848,151	(2,641)	(655,145)
Ending balance (in shares) at Sep. 30, 2019			98,948,935
Beginning balance at Mar. 31, 2019		126,394		783,941	(1,742)	(655,805)
Beginning balance (in shares) at Mar. 31, 2019			95,692,797
Increase (Decrease) in Stockholders' Equity [Roll Forward]
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)
Ending balance at Jun. 30, 2019		158,906		818,338	(2,357)	(657,075)
Ending balance (in shares) at Jun. 30, 2019			97,858,876
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation to employees		14,338		14,338
Exercise of options and warrants and vested RSUs		15,475		15,475
Exercise of options and warrants and vested RSUs (in shares)			1,090,059
Other comprehensive income (loss), net of tax benefit		(284)			(284)
Net income (loss)		1,930				1,930
Ending balance at Sep. 30, 2019		$ 190,365		$ 848,151	$ (2,641)	$ (655,145)
Ending balance (in shares) at Sep. 30, 2019			98,948,935

[1] Resulting from the adoption of ASC 606.