Stockholders' Equity - Narrative (Details) shares in Millions	12 Months Ended
Jan. 03, 2016 shares
2015 Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in the maximum number of shares of common stock authorized for issuance	2.7
2015 Illumina and 2005 Solexa Equity Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance	7.4

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant