Marketable Securities (Details) (Marketable debt securities [Member], USD $) In Thousands, unless otherwise specified	Jun. 29, 2014	Dec. 29, 2013
Investment [Line Items]
Short-term marketable securities	$ 383,227	$ 364,880
Long-term marketable securities	213,766	176,155
U.S. Treasury securities [Member]
Investment [Line Items]
Short-term marketable securities	110,964	143,510
Corporate debt securities [Member]
Investment [Line Items]
Short-term marketable securities	123,070	78,991
Long-term marketable securities	125,205	98,979
U.S. agency securities [Member]
Investment [Line Items]
Short-term marketable securities	46,036	31,518
Long-term marketable securities	83,095	73,697
Municipal securities [Member]
Investment [Line Items]
Short-term marketable securities	43,587	48,035
Long-term marketable securities	5,466	3,479
Certificates of deposit [Member]
Investment [Line Items]
Short-term marketable securities	52,076	31,949
Commercial paper [Member]
Investment [Line Items]
Short-term marketable securities	$ 7,494	$ 30,877