Investments - Marketable Debt Securities (Details) - USD ($) $ in Thousands	12 Months Ended
Jan. 02, 2016	Jan. 03, 2015	Dec. 28, 2013
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Gross Realized Gains (Losses), Sale Proceeds	$ 127,500	$ 54,200	$ 53,300
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	0	20
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	23	75
Available-for-sale Debt Securities, Amortized Cost Basis	15,143	114,105
Available-for-sale Securities, Debt Securities	15,120	114,050
Amortized Cost [Abstract]
Marketable debt securities - current (due in less than one year)	6,575	69,607
Marketable debt securities - non-current (due in one to two years)	8,568	44,498
Marketable debt securities	15,143	114,105
Fair Value [Abstract]
Marketable debt securities - current (due in less than one year)	6,567	69,609
Marketable debt securities - non-current (due in one to two years)	8,553	44,441
U.S. Treasury securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax		12
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax		23
Available-for-sale Debt Securities, Amortized Cost Basis		32,507
Available-for-sale Securities, Debt Securities		32,496
Amortized Cost [Abstract]
Marketable debt securities		32,507
Corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	0	2
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	19	36
Available-for-sale Debt Securities, Amortized Cost Basis	7,532	35,409
Available-for-sale Securities, Debt Securities	7,513	35,375
Amortized Cost [Abstract]
Marketable debt securities	7,532	35,409
U.S. Agency bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	0	4
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	1	10
Available-for-sale Debt Securities, Amortized Cost Basis	2,497	22,545
Available-for-sale Securities, Debt Securities	2,496	22,539
Amortized Cost [Abstract]
Marketable debt securities	2,497	22,545
Municipal bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax	0	2
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	3	5
Available-for-sale Debt Securities, Amortized Cost Basis	5,114	11,157
Available-for-sale Securities, Debt Securities	5,111	11,154
Amortized Cost [Abstract]
Marketable debt securities	$ 5,114	11,157
Commercial Paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax		0
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax		1
Available-for-sale Debt Securities, Amortized Cost Basis		12,487
Available-for-sale Securities, Debt Securities		12,486
Amortized Cost [Abstract]
Marketable debt securities		$ 12,487

Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt securities classified as available-for-sale.

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Amount after adjustments of available-for-sale debt securities at cost, maturing in the second fiscal year through the fifth fiscal year following the latest fiscal year. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings less cumulative-effect adjustments, and fair value hedge accounting adjustments. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Fair value of available-for-sale debt securities maturing in the second fiscal year through the fifth fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount after adjustments of available-for-sale debt securities at cost, maturing in the next fiscal year following the latest fiscal year. Adjustments include, but are not limited to, accretion, amortization, collection of cash, previous other-than-temporary impairments (OTTI) recognized in earnings less cumulative-effect adjustments, and fair value hedge accounting adjustments. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Fair value of available-for-sale debt securities maturing in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

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Amount of debt securities categorized neither as held-to-maturity nor trading.

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The total amount of proceeds received for the sale of securities, categorized neither as held-to-maturity nor trading securities, during the reporting period.

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