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
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 12
-Sentence Column A

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- Definition

Amount of investments in debt and equity securities and other forms of securities that provide ownership interests classified as trading.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=66010992&loc=d3e26626-111562

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.4)
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=66010992&loc=d3e26610-111562

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Trading Securities
-URI http://asc.fasb.org/extlink&oid=6526789

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Cost of investments in debt and equity securities and other forms of securities that provide ownership interests classified as trading.

+ References

No definition available.

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- Definition

Amount of unrealized holding gain (loss) recognized in the income statement for investments in debt and equity securities and other forms of securities that provide ownership interests classified as trading.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Trading Securities
-URI http://asc.fasb.org/extlink&oid=6526789

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.7(c))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 35
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=27723805&loc=d3e24584-111560

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27357-111563

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Investments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
Investments (Details) - USD ($) $ in Millions	Jul. 01, 2017	Jul. 02, 2016	Jul. 01, 2017	Jul. 02, 2016	Dec. 31, 2016
Investments
Unrealized gains (losses) on trading securities	$ 33	$ 9	$ 65	$ 13
Trading securities
Investments
Amortized Cost	1,286		1,286		$ 1,236
Fair Value	1,391		1,391		1,277
Domestic equity securities
Investments
Amortized Cost	612		612		444
Fair Value	687		687		482
Domestic debt securities held in mutual funds/ETFs/U.S. Treasuries
Investments
Amortized Cost	272		272		437
Fair Value	274		274		437
Foreign equity securities
Investments
Amortized Cost	261		261		198
Fair Value	289		289		199
High yield securities
Investments
Amortized Cost	108		108		114
Fair Value	108		108		115
Money market funds held in trading accounts
Investments
Amortized Cost	16		16		13
Fair Value	16		16		13
Collateralized loan obligation
Investments
Amortized Cost	13		13		25
Fair Value	13		13		26
Other trading securities
Investments
Amortized Cost	4		4		5
Fair Value	4		4		5
Denominated in foreign currencies \| Money market funds
Investments
Fair Value	1		1		1
Denominated in foreign currencies \| Foreign equity securities
Investments
Fair Value	104		104		91
Denominated in Euros \| Foreign equity securities
Investments
Fair Value	43		43		35
Denominated in Japanese Yen \| Foreign equity securities
Investments
Fair Value	22		22		20
Denominated in British pounds \| Foreign equity securities
Investments
Fair Value	18		18		16
Denominated in Swiss Franc \| Foreign equity securities
Investments
Fair Value	6		6		6
Denominated in other foreign currencies \| Foreign equity securities
Investments
Fair Value	$ 15		$ 15		$ 14