Derivative instruments and hedging activities - Effect Of Derivative Instruments On Consolidated Statements Of Income (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Derivatives designated as hedging instruments
Derivative Instruments, Gain (Loss) [Line Items]
Gain or (loss) recognized in OCI on derivative (effective portion)	$ (19,694)	$ (2,629)
Gain or (loss) reclassified from accumulated OCI into income (effective portion)	554	10,844
Derivatives designated as hedging instruments \| Foreign exchange contracts - forwards \| Net sales
Derivative Instruments, Gain (Loss) [Line Items]
Gain or (loss) recognized in OCI on derivative (effective portion)	(22,813)	(1,286)
Gain or (loss) reclassified from accumulated OCI into income (effective portion)	4,322	11,709
Derivatives designated as hedging instruments \| Foreign exchange contracts - forwards \| Cost of sales
Derivative Instruments, Gain (Loss) [Line Items]
Gain or (loss) recognized in OCI on derivative (effective portion)	1,925	(707)
Gain or (loss) reclassified from accumulated OCI into income (effective portion)	(2,165)	(482)
Derivatives designated as hedging instruments \| Foreign exchange contracts - forwards \| Operating expenses
Derivative Instruments, Gain (Loss) [Line Items]
Gain or (loss) recognized in OCI on derivative (effective portion)	1,194	(636)
Gain or (loss) reclassified from accumulated OCI into income (effective portion)	(1,603)	(383)
Derivatives not designated as hedging instruments
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in income	810	(348)
Derivatives not designated as hedging instruments \| Foreign exchange contracts - forwards
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain (loss) recognized in income	$ 810	$ (348)

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Amount of realized and unrealized gain (loss) of derivative instruments not designated or qualifying as hedging instruments.

+ References

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Amount, before tax and reclassification, of gain (loss) from derivative instrument designated and qualifying cash flow hedge included in assessment of hedge effectiveness.

+ References

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Amount, before tax, of reclassification of gain (loss) from accumulated other comprehensive income (AOCI) for derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness.

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