Derivative instruments and hedging activities (Tables)

9 Months Ended

Sep. 30, 2020

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of balance sheet classification and fair values of derivative instruments

		Fair Value						Notional Amount
			September 30,			December 31,			September 30,		December 31,
	Balance sheet location		2020			2019			2020		2019
		U.S. $ in thousands
Assets derivatives -Foreign exchange contracts, not designated as hedging instruments	Other current assets	$	100		$	63		$	48,847	$	11,001
Assets derivatives -Foreign exchange contracts, designated as cash flow hedging	Other current assets		220			315			25,635		25,045
Liability derivatives -Foreign exchange contracts, not designated as hedging instruments	Accrued expenses and other current liabilities		(534	)		(388	)		30,605		92,929
Liability derivatives -Foreign exchange contracts, designated as hedging instruments	Accrued expenses and other current liabilities		(552	)		(326	)		18,500		45,262
		$	(766	)	$	(336	)	$	123,587	$	174,237