Fair Value of Financial Instruments (Details) (USD $) In Thousands, unless otherwise specified	Mar. 29, 2014	Dec. 28, 2013
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of marketable securities	$ 112,590	$ 106,746
Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total fair value of financial instruments	107,349	101,505
Level 1 | Short-term marketable securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of marketable securities	107,349	101,505
Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Foreign currency forward exchange contracts	5	48
Total fair value of financial instruments	5	48
Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Total fair value of financial instruments	5,241	5,241
Level 3 | Long-term marketable securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of marketable securities	5,241	5,241
Total
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Foreign currency forward exchange contracts	5	48
Total fair value of financial instruments	112,595	106,794
Total | Short-term marketable securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of marketable securities	107,349	101,505
Total | Long-term marketable securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of marketable securities	$ 5,241	$ 5,241