Condensed Consolidated Statements of Changes in Stockholders Equity and Comprehensive Income (Unaudited) (USD $) In Thousands, except Share data		Total USD ($)	TEP [Member] USD ($)	Common Share Outstanding	Capital Stock Expense TEP [Member] USD ($)	Common Stock USD ($)	Common Stock TEP [Member] USD ($)	Accumulated Earnings USD ($)	Accumulated Earnings TEP [Member] USD ($)	Accumulated Other Comprehensive Loss USD ($)	Accumulated Other Comprehensive Loss TEP [Member] USD ($)
Beginning Balance at Dec. 31, 2010		$ 830,756	$ 709,884		$ (6,357)	$ 715,688	$ 858,971	$ 124,837	$ (132,961)	$ (9,769)	$ (9,769)
Beginning Balance, Shares at Dec. 31, 2010	[1]			36,542
Comprehensive Income:
2011 Year-to-Date Net Income		101,787	83,773					101,787	83,773
Unrealized Loss on Cash Flow Hedges (net of income taxes)		(3,222)	(3,190)							(3,222)	(3,190)
Reclassification of Realized Losses on Cash Flow Hedges to Net Income (net of income taxes)		1,761	1,761							1,761	1,761
Employee Benefit Obligations Amortization of SERP Net Prior Service Cost Included in Net Periodic Benefit Cost (net of income taxes)		223	223							223	223
Total Comprehensive Income		100,549	82,567
Dividends, Including Non-Cash Dividend Equivalents		(46,664)						(46,664)
Shares Issued for Stock Options		7,487				7,487
Shares Issued for Stock Options, Shares				281
Shares Issued under Stock Compensation Plans, Shares				57
Other		1,541				1,541
Ending Balance at Sep. 30, 2011		893,669	792,451		(6,357)	724,716	858,971	179,960	(49,188)	(11,007)	(10,975)
Ending Balance, Shares at Sep. 30, 2011	[1]			36,880
Beginning Balance at Jun. 30, 2011
Comprehensive Income:
2011 Year-to-Date Net Income		59,712	53,912
Ending Balance at Sep. 30, 2011		$ 893,669	$ 792,451		$ (6,357)		$ 858,971

[1] UniSource Energy has 75 million authorized shares of Common Stock.