Marketable Securities (Details) (Marketable debt securities [Member], USD $) In Thousands, unless otherwise specified	Mar. 30, 2014	Dec. 29, 2013
Investment [Line Items]
Short-term marketable securities	$ 419,715	$ 364,880
Long-term marketable securities	244,853	176,155
U.S. Treasury securities [Member]
Investment [Line Items]
Short-term marketable securities	141,179	143,510
Corporate debt securities [Member]
Investment [Line Items]
Short-term marketable securities	99,135	78,991
Long-term marketable securities	143,207	98,979
U.S. agency securities [Member]
Investment [Line Items]
Short-term marketable securities	39,025	31,518
Long-term marketable securities	96,123	73,697
Municipal securities [Member]
Investment [Line Items]
Short-term marketable securities	58,393	48,035
Long-term marketable securities	5,523	3,479
Certificates of deposit [Member]
Investment [Line Items]
Short-term marketable securities	59,499	31,949
Commercial paper [Member]
Investment [Line Items]
Short-term marketable securities	$ 22,484	$ 30,877