Comparative Condensed Consolidated Statements of Cash Flows (Unaudited) (USD $) In Thousands	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010
Cash Flows from Operating Activities
Cash Receipts from Electric Retail Sales	$ 505,446	$ 475,942
Cash Receipts from Gas Sales	104,787	104,771
Cash Receipts from Electric Wholesale Sales	89,266	79,867
Cash Receipts from Operating Springerville Units 3 & 4	54,206	48,016
Interest Received	3,856	5,109
Performance Deposits Received	4,700	6,740
Other Cash Receipts	11,608	14,529
Payment of Other Operations and Maintenance Costs	(146,538)	(107,667)
Purchased Energy Costs Paid	(139,841)	(159,093)
Fuel Costs Paid	(124,261)	(112,969)
Taxes Other Than Income Taxes Paid, Net of Amounts Capitalized	(87,102)	(79,850)
Wages Paid, Net of Amounts Capitalized	(62,476)	(63,382)
Interest Paid, Net of Amounts Capitalized	(33,582)	(28,851)
Capital Lease Interest Paid	(23,821)	(25,111)
Performance Deposit Payments	(3,340)	(6,840)
Income Taxes Paid	(700)	(2,228)
Other Cash Payments	(3,096)	(3,993)
Net Cash Flows - Operating Activities	149,112	144,990
Cash Flows from Investing Activities
Capital Expenditures	(174,136)	(132,998)
Purchase of Sundt Unit 4 Lease Asset		(51,389)
Prepayment Deposit on UED Debt		(1,530)
Purchase of Intangibles - Renewable Energy Credits	(2,529)	(4,084)
Other Cash Payments	(578)	(461)
Return of Investment in Springerville Lease Debt	38,353	21,667
Other Cash Receipts	6,984	5,198
Net Cash Flows - Investing Activities	(131,906)	(163,597)
Cash Flows from Financing Activities
Proceeds from Borrowings Under Revolving Credit Facility	160,000	163,000
Proceeds from Issuance of Long-Term Debt	11,080	39,570
Proceeds from Stock Options Exercised	6,541	5,091
Other Cash Receipts	2,573	5,037
Repayments of Borrowings Under Revolving Credit Facilities	(70,000)	(116,000)
Payments of Capital Lease Obligations	(62,473)	(44,905)
Common Stock Dividends Paid	(30,881)	(28,138)
Repayment of Long-Term Debt	(2,840)	(17,945)
Payment of Debt Issue/Retirement Costs	(282)	(1,955)
Other Cash Payments	(744)	(661)
Net Cash Flows - Financing Activities	12,974	3,094
Net Increase (Decrease) in Cash and Cash Equivalents	30,180	(15,513)
Cash and Cash Equivalents, Beginning of Year	67,599	76,922
Cash and Cash Equivalents, End of Period	97,779	61,409
TEP [Member]
Cash Flows from Operating Activities
Cash Receipts from Electric Retail Sales	409,089	392,196
Cash Receipts from Electric Wholesale Sales	77,696	87,956
Cash Receipts from Operating Springerville Units 3 & 4	54,206	48,016
Reimbursement of Affiliate Charges	9,758	10,210
Interest Received	3,823	5,094
Income Tax Refunds Received	1,805	3,369
Performance Deposits Received		1,540
Other Cash Receipts	8,088	8,441
Payment of Other Operations and Maintenance Costs	(139,590)	(101,435)
Fuel Costs Paid	(123,040)	(108,820)
Purchased Power Costs Paid	(30,332)	(57,468)
Taxes Other Than Income Taxes Paid, Net of Amounts Capitalized	(63,338)	(59,033)
Wages Paid, Net of Amounts Capitalized	(51,042)	(51,163)
Interest Paid, Net of Amounts Capitalized	(22,245)	(18,299)
Capital Lease Interest Paid	(23,821)	(25,106)
Performance Deposit Payments	(1,140)	(1,540)
Income Taxes Paid	(1,811)	(1,828)
Other Cash Payments	(1,841)	(1,561)
Net Cash Flows - Operating Activities	106,265	130,569
Cash Flows from Investing Activities
Capital Expenditures	(130,418)	(111,597)
Purchase of Sundt Unit 4 Lease Asset		(51,389)
Purchase of Intangibles - Renewable Energy Credits	(2,601)	(4,916)
Other Cash Payments	(558)	(1)
Return of Investment in Springerville Lease Debt	38,353	21,667
Other Cash Receipts	4,478	2,918
Net Cash Flows - Investing Activities	(90,746)	(143,318)
Cash Flows from Financing Activities
Proceeds from Borrowings Under Revolving Credit Facility	110,000	110,000
Proceeds from Issuance of Long-Term Debt	11,080	30,000
Equity Investment from Parent		15,000
Other Cash Receipts	764	400
Repayments of Borrowings Under Revolving Credit Facilities	(60,000)	(100,000)
Payments of Capital Lease Obligations	(62,435)	(44,851)
Payment of Debt Issue/Retirement Costs	(162)	(1,361)
Other Cash Payments	(427)	(202)
Net Cash Flows - Financing Activities	(1,180)	8,986
Net Increase (Decrease) in Cash and Cash Equivalents	14,339	(3,763)
Cash and Cash Equivalents, Beginning of Year	19,983	22,418
Cash and Cash Equivalents, End of Period	$ 34,322	$ 18,655