v3.25.1
Cover Page - shares
3 Months Ended
Mar. 31, 2025
May 06, 2025
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Mar. 31, 2025  
Document Transition Report false  
Entity File Number 1-5924  
Entity Registrant Name TUCSON ELECTRIC POWER CO  
Entity Incorporation, State or Country Code AZ  
Entity Tax Identification Number 86-0062700  
Entity Address, Address Line One 88 East Broadway Boulevard  
Entity Address, City or Town Tucson  
Entity Address, State or Province AZ  
Entity Address, Postal Zip Code 85701  
City Area Code 520  
Local Phone Number 571-4000  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Common Stock, Shares Outstanding   32,139,434
Amendment Flag false  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q1  
Entity Central Index Key 0000100122  
Current Fiscal Year End Date --12-31  
No Insider Trading Flag true