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Stockholders' Equity - Narrative - Employee Stock Purchase Plan (Details) - ESPP [Member] - Employee stock [Member] - shares
shares in Millions
12 Months Ended
Dec. 31, 2017
Jan. 01, 2017
Jan. 03, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
ESPP number of shares reserved for issuance 15.5    
Specified percentage of the fair market value of the common stock on the first or last day of the offering period whichever is lower at which stock is purchased 85.00%    
Total shares issued under the ESPP 0.3 0.2 0.2
Shares available for issuance 14.0 14.3