Line items represent reporting concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Investments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
Investments (Details) - USD ($) $ in Millions	Oct. 01, 2016	Oct. 03, 2015	Oct. 01, 2016	Oct. 03, 2015	Dec. 31, 2015
Investments
Total short term investments, amortized cost	$ 1,150		$ 1,150		$ 1,269
Total short term investments, fair value	1,180		1,180		1,254
Unrealized gains (losses) on trading securities	27	$ (22)	41	$ (21)
Available-for-sale securities.
Investments
Amortized Cost					81
Fair Value					81
Money market funds
Investments
Amortized Cost					81
Fair Value					81
Trading securities.
Investments
Amortized Cost	1,150		1,150		1,188
Fair Value	1,180		1,180		1,173
Domestic equity securities
Investments
Amortized Cost	466		466		475
Fair Value	491		491		466
Domestic debt securities
Investments
Amortized Cost	400		400		452
Fair Value	403		403		450
Foreign equity securities
Investments
Amortized Cost	158		158		120
Fair Value	159		159		120
High yield trading debt securities
Investments
Amortized Cost	104		104		108
Fair Value	105		105		104
Collateralized loan obligation
Investments
Amortized Cost	14		14		10
Fair Value	14		14		10
Money market funds held in trading accounts
Investments
Amortized Cost	8		8		22
Fair Value	8		8		22
Other trading securities
Investments
Amortized Cost					1
Fair Value					1
Denominated in foreign currencies \| Money market funds
Investments
Fair Value					3
Denominated in foreign currencies \| Money market funds \| Maximum
Investments
Fair Value	1		1
Denominated in foreign currencies \| Foreign equity securities
Investments
Fair Value	91		91		80
Denominated in Euros \| Foreign equity securities
Investments
Fair Value	34		34		25
Denominated in Japanese Yen \| Foreign equity securities
Investments
Fair Value	19		19		20
Denominated in British pounds \| Foreign equity securities
Investments
Fair Value	15		15		15
Denominated in Swiss Franc \| Foreign equity securities
Investments
Fair Value	7		7		7
Denominated in other foreign currencies \| Foreign equity securities
Investments
Fair Value	$ 16		$ 16		$ 13