Condensed Consolidated Statements of Changes in Stockholders Equity and Comprehensive Income (Unaudited) (Parenthetical) (USD $) In Thousands, except Share data in Millions	9 Months Ended
	Sep. 30, 2011
Comprehensive Income:
Income Tax on Unrealized Loss on Cash Flow Hedges	$ 2,109
Tax on Reclassification of Realized Losses on Cash Flow Hedges to Net Income	1,153
Tax on Employee Benefit Obligations Amortization of SERP Net Prior Service Cost Included in Net Periodic Benefit Cost	141
Common Stock, Shares Authorized	75
TEP [Member]
Comprehensive Income:
Income Tax on Unrealized Loss on Cash Flow Hedges	2,088
Tax on Reclassification of Realized Losses on Cash Flow Hedges to Net Income	1,153
Tax on Employee Benefit Obligations Amortization of SERP Net Prior Service Cost Included in Net Periodic Benefit Cost	141
TEP [Member] | Accumulated Other Comprehensive Loss
Comprehensive Income:
Income Tax on Unrealized Loss on Cash Flow Hedges	2,088
Tax on Reclassification of Realized Losses on Cash Flow Hedges to Net Income	1,153
Tax on Employee Benefit Obligations Amortization of SERP Net Prior Service Cost Included in Net Periodic Benefit Cost	141
Accumulated Other Comprehensive Loss
Comprehensive Income:
Income Tax on Unrealized Loss on Cash Flow Hedges	2,109
Tax on Reclassification of Realized Losses on Cash Flow Hedges to Net Income	1,153
Tax on Employee Benefit Obligations Amortization of SERP Net Prior Service Cost Included in Net Periodic Benefit Cost	$ 141