Commitments and Contingencies (Foreign Currency Contracts) (Details) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 29, 2017 USD ($)	Sep. 30, 2016 USD ($)	Sep. 29, 2017 USD ($)	Sep. 30, 2016 USD ($)	Jan. 01, 2016 USD ($)
Foreign Currency Cash Flow Hedges [Abstract]
Increase in sales	$ 594	$ 0	$ 733	$ 0
Increase (decrease) in cost of sales	(512)	929	371	2,316
Ineffective portion of change in fair value	0	$ 0	0	$ 0
Foreign Currency Cash Flow Hedge [Line Items]
Payments for termination of foreign currency contract					$ 2,400
Foreign currency cash flow hedge gain (loss) to be reclassified	1,000		1,000
Terminated FX Contract [Member]
Foreign Currency Cash Flow Hedge [Line Items]
Foreign currency cash flow hedge gain (loss) to be reclassified					$ (1,600)
FX Contract 3 [Member]
Foreign Currency Cash Flow Hedge [Line Items]
Aggregate Notional Amount	6,163		$ 6,163
Start Date			Jan. 01, 2017
End Date			Dec. 29, 2017
FX Contract 4 [Member]
Foreign Currency Cash Flow Hedge [Line Items]
Aggregate Notional Amount	6,448		$ 6,448
Start Date			Feb. 25, 2017
End Date			Dec. 29, 2017
Accrued Expenses [Member] | FX Contract 3 [Member]
Foreign Currency Cash Flow Hedge [Line Items]
Foreign Currency Cash Flow Hedge Asset at Fair Value	366		$ 366
Accrued Expenses [Member] | FX Contract 4 [Member]
Foreign Currency Cash Flow Hedge [Line Items]
Foreign Currency Cash Flow Hedge Asset at Fair Value	$ 660		$ 660
Peso [Member] | FX Contract 3 [Member]
Foreign Currency Cash Flow Hedge [Line Items]
$/Foreign Currency	0.0514		0.0514
Euro [Member] | FX Contract 4 [Member]
Foreign Currency Cash Flow Hedge [Line Items]
$/Foreign Currency	1.0747		1.0747