Marketable Securities Composition (Details) (USD $) In Thousands, unless otherwise specified	Jun. 28, 2014	Jun. 19, 2014	Dec. 28, 2013
Schedule of Available-for-sale Securities [Line Items]
Maturities of less than five years	$ 109,061		$ 101,505
Maturities of more than ten years	0		5,241
Total marketable securities	109,061		106,746
Federally-insured or FFELP guaranteed student loan auction rate securities
Schedule of Available-for-sale Securities [Line Items]
Total marketable securities	0	5,200	5,241
Short-term marketable securities | Corporate and government bonds and notes and commercial paper
Schedule of Available-for-sale Securities [Line Items]
Total marketable securities	109,061		101,505
Long-term marketable securities | Federally-insured or FFELP guaranteed student loan auction rate securities
Schedule of Available-for-sale Securities [Line Items]
Total marketable securities	$ 0		$ 5,241