Derivatives and Hedging Activities Assets Liabilities Balance Sheet Location (Details) - Foreign Exchange Contract [Member] - USD ($) $ in Thousands	Sep. 29, 2017	Dec. 31, 2016
Derivatives, Fair Value [Line Items]
Derivative Asset, Current	$ 13	$ 54
Derivative Liability, Current	45	40
Not Designated as Hedging Instrument [Member] | Prepaid Expenses and Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Current	13	54
Not Designated as Hedging Instrument [Member] | Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Current	$ 45	$ 40