| Company's assets and liabilities measured at fair value for each fair value hierarchy level [Table Text Block] |
A summary of the Company’s assets and liabilities that are measured at fair value for each fair value hierarchy level for the periods presented is as follows: | | | | | | | | | | | | | | | | | | September 28, 2018 | | Level
One | | Level
Two | | Level
Three | | Total | | (In thousands) | Assets: | | | | | | | | Cash equivalents | $ | 29,760 |
| | $ | — |
| | $ | — |
| | $ | 29,760 |
| Foreign currency contracts related to sales - designated as hedges | — |
| | 357 |
| | — |
| | 357 |
| Foreign currency contracts related to sales - not designated as hedges | — |
| | 564 |
| | — |
| | 564 |
| Foreign currency contracts related to purchases - designated as hedges | — |
| | 735 |
| | — |
| | 735 |
| Foreign currency contracts related to purchases - not designated as hedges | — |
| | 405 |
| | — |
| | 405 |
| Deferred compensation plans | — |
| | 8,039 |
| | — |
| | 8,039 |
| | $ | 29,760 |
| | $ | 10,100 |
| | $ | — |
| | $ | 39,860 |
| | | | | | | | | Liabilities: | | | | | | | | Foreign currency contracts related to sales - designated as hedges | $ | — |
| | $ | 2,145 |
| | $ | — |
| | $ | 2,145 |
| Foreign currency contracts related to sales - not designated as hedges | — |
| | 65 |
| | — |
| | 65 |
| Foreign currency contracts related to purchases - designated as hedges | — |
| | 172 |
| | — |
| | 172 |
| Foreign currency contracts related to purchases - not designated as hedges | — |
| | 1,467 |
| | — |
| | 1,467 |
| Deferred compensation plans | — |
| | 8,039 |
| | — |
| | 8,039 |
| | $ | — |
| | $ | 11,888 |
| | $ | — |
| | $ | 11,888 |
|
| | | | | | | | | | | | | | | | | | December 31, 2017 | | Level
One | | Level
Two | | Level
Three | | Total | | (In thousands) | Assets: | | | | | | | | Cash equivalents | $ | 24,083 |
| | $ | — |
| | $ | — |
| | $ | 24,083 |
| Short term investments | — |
| | 149,608 |
| | — |
| | 149,608 |
| Foreign currency contracts related to sales - designated as hedges | — |
| | 3,287 |
| | — |
| | 3,287 |
| Foreign currency contracts related to sales - not designated as hedges | — |
| | 43 |
| | — |
| | 43 |
| Foreign currency contracts related to purchases - designated as hedges | — |
| | 493 |
| | — |
| | 493 |
| Foreign currency contracts related to purchases - not designated as hedges | — |
| | 1,038 |
| | — |
| | 1,038 |
| Deferred compensation plans | — |
| | 6,374 |
| | — |
| | 6,374 |
| | $ | 24,083 |
| | $ | 160,843 |
| | $ | — |
| | $ | 184,926 |
| | | | | | | | | Liabilities: | | | | | | | | Foreign currency contracts related to sales - designated as hedges | $ | — |
| | $ | 1,257 |
| | $ | — |
| | $ | 1,257 |
| Foreign currency contracts related to sales - not designated as hedges | — |
| | 740 |
| | — |
| | 740 |
| Foreign currency contracts related to purchases - designated as hedges | — |
| | 1,332 |
| | — |
| | 1,332 |
| Foreign currency contracts related to purchases - not designated as hedges | — |
| | 449 |
| | — |
| | 449 |
| Deferred compensation plans | — |
| | 6,374 |
| | — |
| | 6,374 |
| | $ | — |
| | $ | 10,152 |
| | $ | — |
| | $ | 10,152 |
|
There were no transfers in or out of Level One, Two or Three during the nine months ended September 28, 2018. |
| Schedule of Foreign Exchange Contracts, Notional Values |
As of September 28, 2018 and December 31, 2017, the Company had foreign currency contracts with the following notional values: | | | | | | | | | | September 28, 2018 | | December 31, 2017 | | (In thousands) | Foreign currency contracts sold - not designated as hedges | $ | 37,782 |
| | $ | 37,143 |
| Foreign currency contracts sold - designated as hedges | 122,612 |
| | 174,194 |
| Foreign currency contracts purchased - not designated as hedges | 115,311 |
| | 103,975 |
| Foreign currency contracts purchased - designated as hedges | 45,293 |
| | 59,055 |
| Total foreign currency derivatives | $ | 320,998 |
| | $ | 374,367 |
|
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| Schedule of Derivative Instruments, Gain (Loss) in Condensed Consolidated Financial Statements [Table Text Block] |
The Company recognized the following in its Condensed Consolidated Financial Statements related to its derivative instruments: | | | | | | | | | | | | | | | | | | Three Months Ended | | Nine Months Ended | | September 28, 2018 | | September 29, 2017 | | September 28, 2018 | | September 29, 2017 | | (In thousands) | Contracts Designated as Hedges: | | | | Foreign Currency Contracts - related to customer sales contracts: | | | | | | | | Unrealized gain | $ | 2 |
| | $ | 798 |
| | $ | 1,286 |
| | $ | 3,515 |
| Realized gain (loss) | 42 |
| | 323 |
| | (4,350 | ) | | 1,950 |
| Foreign Currency Contracts - related to supplier purchase contracts: | | | | | | | | Unrealized (loss) gain | (195 | ) | | 306 |
| | (465 | ) | | 945 |
| Realized (loss) gain | (365 | ) | | (1,022 | ) | | 1,428 |
| | (2,036 | ) | Unrealized gain (loss) on net investment hedges(1) | 671 |
| | (8,308 | ) | | 9,210 |
| | (27,737 | ) | Contracts Not Designated in a Hedge Relationship: | | | | | | | | Foreign Currency Contracts - related to customer sales contracts: | | | | | | | | Unrealized (loss) gain | (476 | ) | | (289 | ) | | 1,173 |
| | (29 | ) | Realized (loss) gain | (596 | ) | | (737 | ) | | (49 | ) | | 853 |
| Foreign Currency Contracts - related to supplier purchases contracts: | | | | | | | | Unrealized gain (loss) | 174 |
| | (104 | ) | | (1,631 | ) | | 500 |
| Realized gain | 397 |
| | 498 |
| | 73 |
| | 243 |
|
(1) The unrealized gain (loss) on net investment hedges is attributable to the change in valuation of Euro denominated debt. |