Cover Page - shares	3 Months Ended	6 Months Ended
	Jun. 30, 2025	Jun. 30, 2025	Jul. 31, 2025
Cover [Abstract]
Document Type		10-Q
Document Quarterly Report		true
Document Period End Date		Jun. 30, 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		Q2
Entity Central Index Key		0000100122
Current Fiscal Year End Date		--12-31
No Insider Trading Flag	true