Deemed Dividend recorded as a result of exchange of a convertible preferred stock financing transaction.

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Shares Issued By Parent To Less Than Wholly Owned Subsidiary

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Shares Issued To Parent From Less Than Wholly Owned Subsidiary

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Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation.

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The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

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The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

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The cash outflow associated with the acquisition of or advances to an entity that is related to it but not strictly controlled (for example, an unconsolidated subsidiary, affiliate, and joint venture or equity method investment) or the acquisition of an additional interest in a subsidiary (controlled entity).

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Amount of cash inflow from a noncontrolling interest. Includes, but is not limited to, purchase of additional shares or other increase in noncontrolling interest ownership.

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Number of new stock issued during the period.

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Equity impact of the value of new stock issued during the period. Includes shares issued in an initial public offering or a secondary public offering.

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Balance Sheet Account Details - Narrative - Investment in Consolidated Variable Interest Entities (Details) - USD ($) shares in Millions, $ in Millions		1 Months Ended		12 Months Ended
	Feb. 28, 2017	Jul. 03, 2016	Jan. 31, 2016	Dec. 31, 2017	Jan. 01, 2017	Jan. 03, 2016	Feb. 27, 2017	Jul. 31, 2015	Dec. 28, 2014
Variable Interest Entity [Line Items]
Cash and cash equivalents attributable to variable interest entities				$ 1,225	$ 735	$ 769			$ 636
Contributions from noncontrolling interest owners				79	$ 89	$ 32
GRAIL, Inc. [Member]
Variable Interest Entity [Line Items]
Deemed dividend		$ 10
Deemed dividend, tax effect		$ 10
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Cash and cash equivalents attributable to variable interest entities				$ 18
Variable Interest Entity, Primary Beneficiary [Member] \| GRAIL, Inc. [Member]
Variable Interest Entity [Line Items]
Equity ownership interest percentage							52.00%
Series A financing			$ 120
Amount contributed			40
Contributions from noncontrolling interest owners			$ 80
Variable Interest Entity, Primary Beneficiary [Member] \| Helix Holdings I, LLC [Member]
Variable Interest Entity [Line Items]
Equity ownership interest percentage				50.00%				50.00%
GRAIL Class B [Member] \| Variable Interest Entity, Primary Beneficiary [Member] \| GRAIL, Inc. [Member]
Variable Interest Entity [Line Items]
Series A financing	$ 900
Stock exchanged (in shares)			113
GRAIL Class A-1 Convertible [Member] \| Variable Interest Entity, Primary Beneficiary [Member] \| GRAIL, Inc. [Member]
Variable Interest Entity [Line Items]
Shares authorized by GRAIL issued to Illumina		98
Illumina Class B [Member] \| Variable Interest Entity, Primary Beneficiary [Member] \| GRAIL, Inc. [Member]
Variable Interest Entity [Line Items]
Shares authorized by Illumina issued to GRAIL		98
Helix Holdings I, LLC [Member] \| Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity [Line Items]
Noncontrolling shareholders interest percentage				50.00%