The effective portion of gains on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period.

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The effective portion of loss reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

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The portion of losses on derivative instruments designated and qualifying as hedging instruments representing (a) the amount of the hedge ineffectiveness and (b) the amount, if any, excluded from the assessment of hedge effectiveness.

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Derivative and Hedging Activities gain losses in Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jul. 01, 2016	Jun. 30, 2017	Jul. 01, 2016
Derivatives, Fair Value [Line Items]
Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion	$ 0	$ (22)	$ 0	$ (100)
Other Comprehensive Income (Loss) [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments, Gain Recognized in Other Comprehensive Income (Loss), Effective Portion	0		0	158
Derivative Instruments, Loss Recognized in Other Comprehensive Income (Loss), Effective Portion		(165)
Cost of Sales [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion	0	(3)	0	(13)
Operating Expense [Member]
Derivatives, Fair Value [Line Items]
Derivative Instruments, Loss Reclassified from Accumulated OCI into Income, Effective Portion	0	(19)	0	(87)
Other Nonoperating Income (Expense) [Member]
Derivatives, Fair Value [Line Items]
Losses recognized in income on derivatives (ineffectiveness portion and amount excluded from effectiveness testing)	0	(22)	0	(49)
Other Nonoperating Income (Expense) [Member] \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Gains (losses) recognized in income	$ (53)	$ (50)	$ (185)	$ (334)