|
Financial instruments Fair values of derivative instruments designated as hedging instruments (Details) (USD $)
In Thousands, unless otherwise specified |
Mar. 29, 2015
|
Dec. 31, 2014
|
|---|---|---|
| Derivatives Fair Value [Line Items] | ||
| Total asset derivatives | $ 1,737 | $ 0 |
| Total liability derivatives | 1,553 | 0 |
| Foreign Currency Forward Contract | Prepaid Expenses and Other Current Assets | ||
| Derivatives Fair Value [Line Items] | ||
| Total asset derivatives | 1,737 | 0 |
| Foreign Currency Forward Contract | Other Current Liabilities | ||
| Derivatives Fair Value [Line Items] | ||
| Total liability derivatives | $ 1,553 | $ 0 |