Investments and Fair Value Measurements-AFS Investments (Details 4) - USD ($)		12 Months Ended
		Jan. 03, 2016	Dec. 28, 2014
Fixed Income Securities [Member]
Available-for-sale investments
Amortized Cost	[1]	$ 2,730,700,000	$ 4,233,395,000
Gross Unrealized Gain		2,071,000	10,106,000
Gross Unrealized Loss		(749,000)	(4,740,000)
Fair Value		2,732,022,000	4,238,761,000
U.S. Treasury securities [Member]
Available-for-sale investments
Amortized Cost	[1]	122,891,000	25,194,000
Gross Unrealized Gain		11,000	0
Gross Unrealized Loss		(3,000)	(32,000)
Fair Value		122,899,000	25,162,000
U.S. Government-sponsored agency securities [Member]
Available-for-sale investments
Amortized Cost	[1]	37,447,000	7,511,000
Gross Unrealized Gain		14,000	0
Gross Unrealized Loss		(74,000)	(18,000)
Fair Value		37,387,000	7,493,000
International Government Securities [Member]
Available-for-sale investments
Amortized Cost	[1]	47,463,000	82,033,000
Gross Unrealized Gain		0	0
Gross Unrealized Loss		(16,000)	(314,000)
Fair Value		47,447,000	81,719,000
Corporate notes and bonds [Member]
Available-for-sale investments
Amortized Cost	[1]	471,421,000	774,869,000
Gross Unrealized Gain		52,000	325,000
Gross Unrealized Loss		(559,000)	(2,052,000)
Fair Value		470,914,000	773,142,000
Asset-backed securities [Member]
Available-for-sale investments
Amortized Cost	[1]	133,518,000	171,221,000
Gross Unrealized Gain		3,000	42,000
Gross Unrealized Loss		(75,000)	(353,000)
Fair Value		133,446,000	170,910,000
Mortgage-backed securities [Member]
Available-for-sale investments
Amortized Cost	[1]	12,661,000	48,378,000
Gross Unrealized Gain		0	6,000
Gross Unrealized Loss		(4,000)	(173,000)
Fair Value		12,657,000	48,211,000
Municipal notes and bonds [Member]
Available-for-sale investments
Amortized Cost	[1]	1,905,299,000	3,124,189,000
Gross Unrealized Gain		1,991,000	9,733,000
Gross Unrealized Loss		(18,000)	(1,798,000)
Fair Value		$ 1,907,272,000	$ 3,132,124,000

[1] Amortized cost includes adjustments made to the cost basis of an investment for accretion, amortization and other-than temporary impairment.