v3.19.2
Cover - shares
6 Months Ended
Jun. 30, 2019
Jul. 31, 2019
Cover page.    
Document Type 10-Q  
Amendment Flag false  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2019  
Document Transition Report false  
Entity File Number 001-32269  
Entity Registrant Name EXTRA SPACE STORAGE INC.  
Entity Central Index Key 0001289490  
Current Fiscal Year End Date --12-31  
Document Fiscal Year Focus 2019  
Document Fiscal Period Focus Q2  
Entity Incorporation, State or Country Code MD  
Entity Tax Identification Number 20-1076777  
Entity Address, Address Line One 2795 East Cottonwood Parkway, Suite 300  
Entity Address, City or Town Salt Lake City  
Entity Address, State or Province UT  
Entity Address, Postal Zip Code 84121  
City Area Code 801  
Local Phone Number 365-4600  
Title of 12(b) Security Common Stock, $0.01 par value  
Trading Symbol EXR  
Security Exchange Name NYSE  
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 Common Stock, Shares Outstanding   128,516,944