Condensed Consolidated Statements of Changes in Stockholders Equity and Comprehensive Income (Unaudited) (Parenthetical) (USD $) In Thousands, except Share data in Millions	6 Months Ended
	Jun. 30, 2011
Comprehensive Income:
Income Tax on Unrealized Loss on Cash Flow Hedges	$ 762
Tax on Reclassification of Realized Losses on Cash Flow Hedges to Net Income	431
Tax on Employee Benefit Obligations Amortization of SERP Net Prior Service Cost Included in Net Periodic Benefit Cost	95
Common Stock, Shares Authorized	75
TEP [Member]
Comprehensive Income:
Income Tax on Unrealized Loss on Cash Flow Hedges	762
Tax on Reclassification of Realized Losses on Cash Flow Hedges to Net Income	431
Tax on Employee Benefit Obligations Amortization of SERP Net Prior Service Cost Included in Net Periodic Benefit Cost	95
TEP [Member] | Accumulated Other Comprehensive Loss
Comprehensive Income:
Income Tax on Unrealized Loss on Cash Flow Hedges	762
Tax on Reclassification of Realized Losses on Cash Flow Hedges to Net Income	431
Tax on Employee Benefit Obligations Amortization of SERP Net Prior Service Cost Included in Net Periodic Benefit Cost	95
Accumulated Other Comprehensive Loss
Comprehensive Income:
Income Tax on Unrealized Loss on Cash Flow Hedges	762
Tax on Reclassification of Realized Losses on Cash Flow Hedges to Net Income	431
Tax on Employee Benefit Obligations Amortization of SERP Net Prior Service Cost Included in Net Periodic Benefit Cost	$ 95