Marketable Securities Composition (Details) (USD $) In Thousands, unless otherwise specified	Mar. 29, 2014	Dec. 28, 2013
Schedule of Available-for-sale Securities [Line Items]
Maturities of less than five years	$ 107,349	$ 101,505
Maturities of more than ten years	5,241	5,241
Total marketable securities	112,590	106,746
Federally-insured or FFELP guaranteed student loan auction rate securities
Schedule of Available-for-sale Securities [Line Items]
Total marketable securities	5,241	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	107,349	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	$ 5,241	$ 5,241