Marketable Securities Composition (Details) (USD $) In Thousands, unless otherwise specified	Jan. 03, 2015	Dec. 28, 2013	Jun. 19, 2014
Schedule of Available-for-sale Securities [Line Items]
Fair value of marketable securities	$ 139,233	$ 106,746
Federally-insured or FFELP guaranteed student loan auction rate securities
Schedule of Available-for-sale Securities [Line Items]
Fair value of marketable securities	0		5,200
Short-term marketable securities | Corporate and government bonds and notes and commercial paper
Schedule of Available-for-sale Securities [Line Items]
Maturing within one year	60,965	51,920
Maturing between one and two years	78,268	49,585
Fair value of marketable securities	139,233	101,505
Long-term marketable securities | Federally-insured or FFELP guaranteed student loan auction rate securities
Schedule of Available-for-sale Securities [Line Items]
Maturing in more than ten years	$ 0	$ 5,241