Foreign Currency Contracts Notional Values (Details) - USD ($) $ in Thousands |
Sep. 28, 2018 |
Dec. 31, 2017 |
|---|---|---|
| Derivative, Notional Amount | $ 320,998 | $ 374,367 |
| Foreign currency contracts related to customer sales contracts | Not Designated As Hedging Instrument [Member] | ||
| Derivative, Notional Amount | 37,782 | 37,143 |
| Foreign currency contracts related to customer sales contracts | Designated As Hedging Instrument [Member] | ||
| Derivative, Notional Amount | 122,612 | 174,194 |
| Foreign currency contracts related to supplier purchase contracts | Not Designated As Hedging Instrument [Member] | ||
| Derivative, Notional Amount | 115,311 | 103,975 |
| Foreign currency contracts related to supplier purchase contracts | Designated As Hedging Instrument [Member] | ||
| Derivative, Notional Amount | $ 45,293 | $ 59,055 |