Equity (Tables)

9 Months Ended

Sep. 30, 2020

Stockholders' Equity Note [Abstract]

Schedule of share-based compensation expense

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
		2020		2019		2020		2019
	U.S $ in thousands				U.S $ in thousands
Cost of sales	$	524	$	475	$	1,424	$	1,370
Research and development, net		1,587		1,494		4,846		3,764
Selling, general and administrative		2,765		3,466		9,624		10,623
Total stock-based compensation expenses	$	4,876	$	5,435	$	15,894	$	15,757

Schedule of stock option activity

	Number of Options			Weighted Average Exercise Price
Options outstanding as of January 1, 2020	1,961,532		$	31.16
Granted	360,000			17.10
Exercised	(2,237	)		8.09
Forfeited	(145,504	)		38.71
Options outstanding as of September 30, 2020	2,173,791			28.34
Options exercisable as of September 30, 2020	1,739,420		$	31.03

Schedule of RSUs and PSUs activity

	Number of RSUs and PSUs			Weighted Average Grant Date Fair Value
Unvested as of January 1, 2020	2,362,991		$	24.10
Granted	1,425,536			17.80
Vested	(669,477	)		23.21
Forfeited	(445,400	)		21.97
Unvested as of September 30, 2020	2,673,650		$	21.32

Schedule of accumulated other comprehensive income (loss)

	Nine Months Ended September 30, 2020
		Net Unrealized Loss on Cash Flow Hedges			Foreign Currency Translation Adjustments			Total
	U.S. $ in thousands
Balance as of January 1, 2020	$	(10	)	$	(7,706	)	$	(7,716	)
Other comprehensive loss before reclassifications		(299	)		(611	)		(910	)
Amounts reclassified from accumulated other comprehensive loss		(663	)		-			(663	)
Other comprehensive loss		(962	)		(611	)		(1,573	)
Balance as of September 30, 2020	$	(972	)	$	(8,317	)	$	(9,289	)

	Nine Months Ended September 30, 2019
		Net Unrealized Gain (Loss) on Cash Flow Hedges			Foreign Currency Translation Adjustments			Total
	U.S. $ in thousands
Balance as of January 1, 2019	$	(627	)	$	(7,126	)	$	(7,753	)
Other comprehensive income (loss) before reclassifications		1,689			(1,398	)		291
Amounts reclassified from accumulated other comprehensive loss		(505	)		-			(505	)
Other comprehensive income (loss)		1,184			(1,398	)		(214	)
Balance as of September 30, 2019	$	557		$	(8,524	)	$	(7,967	)