RECLASSIFICATIONS FROM ACCUMULATED OTHER COMPREHENSIVE INCOME BY COMPONENT Reclassifications From Accumulated Other Comprehensive Income By Component) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax [Abstract]
Tax Benefit	$ 430	$ 451	$ 734	$ 820
Realized Losses on Cash Flow Hedges, Net of Taxes	(664)	(690)	(1,309)	(1,255)
Amortization of SERP and Defined Benefit Plans
Prior Service Costs	(40)	(111)	(79)	(222)
Tax Benefit	15	43	30	85
Amortization, Net of Taxes	(25)	(68)	(49)	(137)
Total Reclassification from Other Comprehensive Income for the Period	(689)	(758)	(1,358)	(1,392)
TUCSON ELECTRIC POWER COMPANY
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax [Abstract]
Tax Benefit	408	429	692	781
Realized Losses on Cash Flow Hedges, Net of Taxes	(630)	(659)	(1,240)	(1,193)
Amortization of SERP and Defined Benefit Plans
Prior Service Costs	(40)	(111)	(79)	(222)
Tax Benefit	15	43	30	85
Amortization, Net of Taxes	(25)	(68)	(49)	(137)
Total Reclassification from Other Comprehensive Income for the Period	(655)	(727)	(1,289)	(1,330)
Interest Rate Contract Long Term Debt [Member]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax [Abstract]
Other Comprehensive Income (Loss), realized Gain (Loss) on Derivatives Arising During Period, before Tax	(349)	(346)	(702)	(676)
Interest Rate Contract Long Term Debt [Member] | TUCSON ELECTRIC POWER COMPANY
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax [Abstract]
Other Comprehensive Income (Loss), realized Gain (Loss) on Derivatives Arising During Period, before Tax	(293)	(293)	(591)	(575)
Interest Rate contract Capital Leases [Member]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax [Abstract]
Other Comprehensive Income (Loss), realized Gain (Loss) on Derivatives Arising During Period, before Tax	(602)	(604)	(1,198)	(1,208)
Interest Rate contract Capital Leases [Member] | TUCSON ELECTRIC POWER COMPANY
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax [Abstract]
Other Comprehensive Income (Loss), realized Gain (Loss) on Derivatives Arising During Period, before Tax	(602)	(604)	(1,198)	(1,208)
Commodity Contract [Member]
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax [Abstract]
Other Comprehensive Income (Loss), realized Gain (Loss) on Derivatives Arising During Period, before Tax	(143)	(191)	(143)	(191)
Commodity Contract [Member] | TUCSON ELECTRIC POWER COMPANY
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax [Abstract]
Other Comprehensive Income (Loss), realized Gain (Loss) on Derivatives Arising During Period, before Tax	$ (143)	$ (191)	$ (143)	$ (191)