Marketable Securities Composition (Details) - Short-term marketable securities - USD ($) $ in Thousands	Jul. 04, 2015	Jan. 03, 2015
Schedule of Available-for-sale Securities [Line Items]
Maturing within one year	$ 19,625	$ 60,965
Maturing between one and two years	17,012	78,268
Total marketable securities	36,637	139,233
Corporate and Government Bonds and Notes and Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Total marketable securities	31,020	139,233
Commercial Paper, Not Included with Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Total marketable securities	$ 5,617	$ 0