Marketable Securities Composition (Details) (USD $) In Thousands, unless otherwise specified	Apr. 04, 2015	Jan. 03, 2015
Schedule of Available-for-sale Securities [Line Items]
Total marketable securities	$ 40,127	$ 139,233
Short-term marketable securities
Schedule of Available-for-sale Securities [Line Items]
Maturing within one year	17,635	60,965
Maturing between one and two years	22,492	78,268
Total marketable securities	40,127	139,233
Corporate and Government Bonds and Notes and Commercial Paper [Member] | Short-term marketable securities
Schedule of Available-for-sale Securities [Line Items]
Total marketable securities	34,498	139,233
Commercial Paper, Not Included with Cash and Cash Equivalents [Member] | Short-term marketable securities
Schedule of Available-for-sale Securities [Line Items]
Total marketable securities	$ 5,629	$ 0