SUPPLEMENTAL CASH FLOW INFORMATION (Non-Cash Transactions) (Details) (USD $)	12 Months Ended								1 Months Ended	12 Months Ended		1 Months Ended			12 Months Ended
	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2013 UNS Energy	Dec. 31, 2012 UNS Energy	Oct. 31, 2013 Springerville Unit One Lease [Member] TUCSON ELECTRIC POWER COMPANY	Dec. 31, 2012 Convertible Debt [Member] UNS Energy	Dec. 31, 2005 Convertible Debt [Member] UNS Energy	Apr. 30, 2013 Unsecured Debt [Member] TUCSON ELECTRIC POWER COMPANY	Jun. 30, 2012 Unsecured Debt [Member] TUCSON ELECTRIC POWER COMPANY	Mar. 31, 2012 Unsecured Debt [Member] TUCSON ELECTRIC POWER COMPANY	Dec. 31, 2012 Unsecured Debt [Member] TUCSON ELECTRIC POWER COMPANY	Mar. 31, 2013 Unsecured Debt [Member] TUCSON ELECTRIC POWER COMPANY	Sep. 30, 2012 Unsecured Debt [Member] TUCSON ELECTRIC POWER COMPANY	Nov. 30, 2013 Variable Rate Bonds [Member] Unsecured Debt [Member] TUCSON ELECTRIC POWER COMPANY
Document Fiscal Year Focus	2013
Increase in Capital Lease Obligation									$ 55,000,000
Debt instrument, face amount											150,000,000		16,000,000	177,000,000		91,000,000	150,000,000	100,000,000
Debt extinguishment												91,000,000	16,000,000	184,000,000	193,000,000
Converted Notes principal										147,000,000
(Decrease)/Increase to Utility Plant Accruals	4,995,000	[1]	4,813,000	[1]	(2,741,000)	[1]
Net Cost Of Removal Of Interim Retirements	25,182,000	[2]	35,983,000	[2]	31,626,000	[2]
Change In Capital Lease Obligations	9,039,000	[3]	11,967,000	[3]	15,162,000	[3]
Asset Retirement Obligations	$ 8,064,000	[4]	$ 789,000	[4]	$ 7,638,000	[4]	$ 1,000,000	$ 0

[1] The non-cash additions to Utility Plant represent accruals for capital expenditures.

[2] The non-cash net cost of removal of interim retirements represents an accrual for future asset retirement obligations that does not impact earnings.

[3] The non-cash change in capital lease obligations represents interest accrued for accounting purposes in excess of interest payments.

[4] The non-cash additions to asset retirement obligations and related capitalized assets represent revision of estimated asset retirement cost due to changes in timing and amount of expected future asset retirement obligations.