CONDENSED CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY (USD $) In Thousands, unless otherwise specified	Total USD ($)	TUCSON ELECTRIC POWER COMPANY USD ($)	Common Shares Outstanding [Member]	Common Stock [Member] USD ($)	Common Stock [Member] TUCSON ELECTRIC POWER COMPANY USD ($)	Capital Stock Expense [Member] TUCSON ELECTRIC POWER COMPANY USD ($)	Accumulated Earnings/(Deficit) [Member] USD ($)	Accumulated Earnings/(Deficit) [Member] TUCSON ELECTRIC POWER COMPANY USD ($)	Accumulated Other Comprehensive Loss [Member] USD ($)	Accumulated Other Comprehensive Loss [Member] TUCSON ELECTRIC POWER COMPANY USD ($)
Balances at Dec. 31, 2012	$ 1,065,465	$ 860,927		$ 882,138	$ 888,971	$ (6,357)	$ 193,117	$ (12,157)	$ (9,790)	$ (9,530)
Balances, shares at Dec. 31, 2012			41,344
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	113,953	96,433					113,953	96,433
Other Comprehensive Income (Loss), Net of Tax	2,434	2,361							2,434	2,361
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	116,387	98,794
Dividends, Including Non-Cash Dividend Equivalents	(54,733)						(54,733)
Stock Issued During Period, Shares, Dividend Reinvestment Plan			9
Stock Issued During Period, Value, Dividend Reinvestment Plan	408			408
Shares Issued for Stock Options	2,724			2,724
Shares Issued for Stock Options, shares			85
Shares Issued Under Performance Share Awards	0			0
Shares Issued Under Performance Share Awards, shares			57
Other	2,035			2,035
Payments of Dividends		(20,000)						(20,000)
Balances at Sep. 30, 2013	1,132,286	939,721		887,305	888,971	(6,357)	252,337	64,276	(7,356)	(7,169)
Balances, shares at Sep. 30, 2013			41,495
Balances at Jun. 30, 2013
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	67,990	64,167
Other Comprehensive Income (Loss), Net of Tax	753	768
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	68,743	64,935
Balances at Sep. 30, 2013	$ 1,132,286	$ 939,721			$ 888,971	$ (6,357)