Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	6 Months Ended
	Jul. 01, 2017	Jul. 02, 2016	Dec. 31, 2016
Total
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Foreign currency forward exchange contracts, net	$ 26		$ 184
Total fair value of financial instruments	10,496		10,492
Short-term marketable securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of marketable securities	10,470		10,308
Short-term marketable securities | Total
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of marketable securities	10,470		10,308
Level 1
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Foreign currency forward exchange contracts, net	0		0
Total fair value of financial instruments	10,382		10,230
Level 1 | Short-term marketable securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of marketable securities	10,382		10,230
Level 2
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Foreign currency forward exchange contracts, net	26		184
Total fair value of financial instruments	114		262
Level 2 | Short-term marketable securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of marketable securities	88		78
Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Foreign currency forward exchange contracts, net	0		0
Total fair value of financial instruments	0		0
Level 3 | Short-term marketable securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Fair value of marketable securities	0		$ 0
Maximum | Short-term marketable securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Unrealized loss (less than)	$ 100	$ 100