Marketable Securities Composition (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Jan. 02, 2016
Schedule of Available-for-sale Securities [Line Items]
Term of maturities of investments considered short-term	2 years
Short-term marketable securities
Schedule of Available-for-sale Securities [Line Items]
Maturing within one year	$ 10,308	$ 12,144
Maturing between one and two years	0	5,824
Short-term marketable securities	10,308	17,968
Short-term marketable securities | Corporate and government bonds and notes
Schedule of Available-for-sale Securities [Line Items]
Short-term marketable securities	10,230	17,888
Short-term marketable securities | Certificates of deposit
Schedule of Available-for-sale Securities [Line Items]
Short-term marketable securities	$ 78	$ 80