Document and Entity Information - shares
6 Months Ended
Jun. 30, 2019
Aug. 02, 2019
Cover page.    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2019  
Document Transition Report false  
Entity File Number 001-33031  
Entity Registrant Name SHUTTERFLY, INC.  
Entity Incorporation, State or Country Code DE  
Entity Tax Identification Number 94-3330068  
Entity Address, Address Line One 2800 Bridge Parkway  
Entity Address, City or Town Redwood City,  
Entity Address, State or Province CA  
Entity Address, Postal Zip Code 94065  
City Area Code (650)  
Local Phone Number 610-5200  
Title of 12(b) Security Common Stock, 0.0001 Par Value Per Share  
Trading Symbol SFLY  
Security Exchange Name NASDAQ  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Central Index Key 0001125920  
Current Fiscal Year End Date --12-31  
Entity Common Stock, Shares Outstanding   34,395,673
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q2  
Amendment Flag false