Investments and Fair Value Measurements-AFS Investments (Details 4) - USD ($)		Apr. 03, 2016	Jan. 03, 2016
Fixed Income Securities [Member]
Available-for-sale investments
Amortized Cost	[1]	$ 1,427,647,000	$ 2,730,700,000
Gross Unrealized Gain		1,061,000	2,071,000
Gross Unrealized Loss		(124,000)	(749,000)
Fair Value		1,428,584,000	2,732,022,000
U.S. Treasury securities [Member]
Available-for-sale investments
Amortized Cost	[1]	36,547,000	122,891,000
Gross Unrealized Gain		35,000	11,000
Gross Unrealized Loss		0	(3,000)
Fair Value		36,582,000	122,899,000
U.S. Government-sponsored agency securities [Member]
Available-for-sale investments
Amortized Cost	[1]	21,138,000	37,447,000
Gross Unrealized Gain		97,000	14,000
Gross Unrealized Loss		0	(74,000)
Fair Value		21,235,000	37,387,000
International Government Securities [Member]
Available-for-sale investments
Amortized Cost	[1]	1,664,000	47,463,000
Gross Unrealized Gain		0	0
Gross Unrealized Loss		(3,000)	(16,000)
Fair Value		1,661,000	47,447,000
Corporate notes and bonds [Member]
Available-for-sale investments
Amortized Cost	[1]	260,940,000	471,421,000
Gross Unrealized Gain		357,000	52,000
Gross Unrealized Loss		(106,000)	(559,000)
Fair Value		261,191,000	470,914,000
Asset-backed securities [Member]
Available-for-sale investments
Amortized Cost	[1]	45,080,000	133,518,000
Gross Unrealized Gain		32,000	3,000
Gross Unrealized Loss		(14,000)	(75,000)
Fair Value		45,098,000	133,446,000
Mortgage-backed securities [Member]
Available-for-sale investments
Amortized Cost	[1]	2,149,000	12,661,000
Gross Unrealized Gain		2,000	0
Gross Unrealized Loss		(1,000)	(4,000)
Fair Value		2,150,000	12,657,000
Municipal notes and bonds [Member]
Available-for-sale investments
Amortized Cost	[1]	1,060,129,000	1,905,299,000
Gross Unrealized Gain		538,000	1,991,000
Gross Unrealized Loss		0	(18,000)
Fair Value		$ 1,060,667,000	$ 1,907,272,000

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