El Paso Electric 10-K27 Feb 152014 FY Annual reportFinancial data

Company Profile

Document_And_Entity_Informatio

Document And Entity Information (USD $)	12 Months Ended
Document And Entity Information (USD $)	Dec. 31, 2014	Jan. 31, 2015	Jun. 30, 2014
Document and Entity Information [Line Items]
Entity Registrant Name	EL PASO ELECTRIC CO /TX/
Entity Central Index Key	31978
Trading Symbol	EE
Current Fiscal Year End Date	-19
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	31-Dec-14
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	FY
Amendment Flag	FALSE
Entity Common Stock, Shares Outstanding		40,352,478
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$1,597,139,431

BALANCE_SHEETS

BALANCE SHEETS (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Utility plant:
Electric plant in service	$3,229,255	$3,076,549
Less accumulated depreciation and amortization	-1,266,672	-1,214,088
Net plant in service	1,962,583	1,862,461
Construction work in progress	414,284	282,647
Nuclear fuel; includes fuel in process of $46,996 and $48,492, respectively	185,185	188,185
Less accumulated amortization	-73,701	-75,820
Net nuclear fuel	111,484	112,365
Net utility plant	2,488,351	2,257,473
Current assets:
Cash and cash equivalents	40,504	25,592
Accounts receivable, principally trade, net of allowance for doubtful accounts of $2,253 and $2,261, respectively	71,165	65,350
Accumulated deferred income taxes	13,957	26,965
Inventories, at cost	45,889	45,942
Under-collection of fuel revenues	10,253	7,248
Prepayments and other	12,213	7,694
Total current assets	193,981	178,791
Deferred charges and other assets:
Decommissioning trust funds	234,286	214,095
Regulatory assets	112,086	101,050
Other	30,597	34,879
Total deferred charges and other assets	376,969	350,024
Total assets	3,059,301	2,786,288
Capitalization:
Common stock, stated value $1 per share, 100,000,000 shares authorized, 65,725,246 and 65,639,091 shares issued, and 124,297 and 120,534 restricted shares, respectively	65,850	65,760
Capital in excess of stated value	318,515	314,443
Retained earnings	1,032,537	985,665
Accumulated other comprehensive income (loss), net of tax	-8,001	2,612
Total stockholders equity subtotal before treasury stock	1,408,901	1,368,480
Treasury stock, 25,492,919 shares at cost	-424,647	-424,647
Common stock equity	984,254	943,833
Long-term debt	1,134,179	999,620
Total capitalization	2,118,433	1,943,453
Current liabilities:
Current maturities of long-term debt	15,000	0
Short-term borrowings under the revolving credit facility	14,532	14,352
Accounts payable, principally trade	78,862	61,795
Taxes accrued	28,210	25,206
Interest accrued	12,758	12,189
Over-collection of fuel revenues	932	1,048
Other	24,715	22,932
Total current liabilities	175,009	137,522
Deferred credits and other liabilities:
Accumulated deferred income taxes	474,154	449,925
Accrued pension liability	94,272	84,012
Accrued postretirement benefit liability	59,342	50,655
Asset retirement obligation	74,577	65,214
Regulatory liabilities	26,099	26,416
Other	37,415	29,091
Total deferred credits and other liabilities	765,859	705,313
Commitments and contingencies
Total capitalization and liabilities	$3,059,301	$2,786,288

BALANCE_SHEETS_Parentheticals

BALANCE SHEETS (Parentheticals) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Nuclear fuel; fuel in process	$46,996	$48,492
Allowance for doubtful accounts receivable, current	$2,253	$2,261
Common stock, par or stated value per share	$1	$1
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	65,725,246	65,639,091
Common stock, restricted shares	124,297	120,534
Treasury stock, shares	25,492,919	25,492,919

STATEMENTS_OF_OPERATIONS

STATEMENTS OF OPERATIONS (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating revenues	$917,525	$890,362	$852,881
Energy expenses:
Fuel	251,005	226,768	191,076
Purchased and interchanged power	64,804	62,363	60,251
Cost of services, energy services	315,809	289,131	251,327
Operating revenues net of energy expenses	601,716	601,231	601,554
Other operating expenses:
Other operations	238,832	237,155	236,558
Maintenance	65,629	61,068	60,339
Depreciation and amortization	83,342	79,626	78,556
Taxes other than income taxes	62,750	57,747	57,443
Utilities operating expense	450,553	435,596	432,896
Operating income	151,163	165,635	168,658
Other income (deductions):
Allowance for equity funds used during construction	14,662	10,008	9,427
Investment and interest income, net	13,633	7,033	5,275
Miscellaneous non-operating income	4,075	909	1,415
Miscellaneous non-operating deductions	-4,199	-3,635	-2,013
Nonoperating income (expense)	28,171	14,315	14,104
Interest charges (credits):
Interest on long-term debt and revolving credit facility	59,028	58,635	54,632
Other interest	1,250	431	1,190
Capitalized interest	-5,092	-5,299	-5,312
Allowance for borrowed funds used during construction	-8,368	-6,055	-5,573
Interest expense	46,818	47,712	44,937
Income before income taxes	132,516	132,238	137,825
Income tax expense	41,088	43,655	46,979
Net income	$91,428	$88,583	$90,846
Basic earnings per share	$2.27	$2.20	$2.27
Diluted earnings per share	$2.27	$2.20	$2.26
Dividends declared per share of common stock	$1.10	$1.04	$0.97
Weighted average number of shares outstanding	40,190,991	40,114,594	39,974,022
Weighted average number of shares and dilutive potential shares outstanding	40,211,717	40,126,647	40,055,581

STATEMENTS_OF_COMPREHENSIVE_OP

STATEMENTS OF COMPREHENSIVE OPERATIONS (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Net income	$91,428	$88,583	$90,846
Unrecognized pension and post-retirement benefit costs:
Net gain (loss) arising during period	-54,328	82,964	-2,109
Prior service benefit	34,200	97	0
Reclassification adjustments included in net income for amortization of:
Prior service benefit	-7,659	-5,560	-5,762
Net loss	6,182	10,472	11,971
Net unrealized gains/losses on marketable securities:
Net holding gains arising during period	10,827	17,699	9,927
Reclassification adjustments for net (gains) losses included in net income	-7,350	-553	1,042
Net losses on cash flow hedges:
Reclassification adjustment for interest expense included in net income	438	411	385
Total other comprehensive income (loss) before income taxes	-17,690	105,530	15,454
Income tax benefit (expense) related to items of other comprehensive income (loss):
Unrecognized pension and post-retirement benefit costs	8,051	-33,566	-1,464
Net unrealized gains on marketable securities	-760	-3,100	-2,438
Losses on cash flow hedges	-214	-168	-131
Total income tax benefit (expense)	7,077	-36,834	-4,033
Other comprehensive income (loss), net of tax	-10,613	68,696	11,421
Comprehensive income	$80,815	$157,279	$102,267

STATEMENTS_OF_CHANGES_IN_COMMO

STATEMENTS OF CHANGES IN COMMON STOCK EQUITY (USD $)	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss), Net of Tax	Treasury Stock
In Thousands, except Share data, unless otherwise specified	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss), Net of Tax	Treasury Stock
Balances at beginning of period at Dec. 31, 2011	$760,251	$65,452	$309,777	$887,174	($77,505)	($424,647)
Balances at beginning of period (in shares) at Dec. 31, 2011		65,452,073				25,492,919
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted common stock grants and deferred compensation (in shares)		87,428
Restricted common stock grants and deferred compensation	1,778	87	1,691
Performance share awards vested (in shares)		174,038
Performance share awards vested	1,193	174	1,019
Stock awards withheld for taxes (in shares)		-52,778
Stock awards withheld for taxes	-1,822	-52	-1,770
Forfeited restricted common stock (in shares)		-88,100
Forfeited restricted common stock	-1,294	-88	-1,206
Deferred taxes on stock incentive plan	1,101		1,101
Stock options exercised, in shares		32,336
Stock options exercised	414	32	382
Net income	90,846			90,846
Other comprehensive income (loss)	11,421				11,421
Dividends, Common Stock, Cash	-38,889			-38,889
Balances at end of period at Dec. 31, 2012	824,999	65,605	310,994	939,131	-66,084	-424,647
Balances at end of period (in shares) at Dec. 31, 2012		65,604,997				25,492,919
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted common stock grants and deferred compensation (in shares)		96,279
Restricted common stock grants and deferred compensation	2,798	96	2,702
Performance share awards vested (in shares)		64,275
Performance share awards vested	849	64	785
Stock awards withheld for taxes (in shares)		-23,808
Stock awards withheld for taxes	-811	-23	-788
Forfeited restricted common stock (in shares)		-1,549
Forfeited restricted common stock	-1	-1
Deferred taxes on stock incentive plan	427		427
Stock options exercised, in shares		15,000
Stock options exercised	192	15	177
Grants of share based compensation (in shares)		4,431
Grants of share based compensation	150	4	146
Net income	88,583			88,583
Other comprehensive income (loss)	68,696				68,696
Dividends, Common Stock, Cash	-42,049			-42,049
Balances at end of period at Dec. 31, 2013	943,833	65,760	314,443	985,665	2,612	-424,647
Balances at end of period (in shares) at Dec. 31, 2013	65,639,091	65,759,625				25,492,919
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted common stock grants and deferred compensation (in shares)		103,672
Restricted common stock grants and deferred compensation	4,279	104	4,175
Stock awards withheld for taxes (in shares)		-4,696
Stock awards withheld for taxes	-188	-5	-183
Forfeited restricted common stock (in shares)		-19,162
Forfeited restricted common stock	-19	-19
Deferred taxes on stock incentive plan	-302		-302
Grants of share based compensation (in shares)		10,104
Grants of share based compensation	392	10	382
Net income	91,428			91,428
Other comprehensive income (loss)	-10,613				-10,613
Dividends, Common Stock, Cash	-44,556			-44,556
Balances at end of period at Dec. 31, 2014	$984,254	$65,850	$318,515	$1,032,537	($8,001)	($424,647)
Balances at end of period (in shares) at Dec. 31, 2014	65,725,246	65,849,543				25,492,919

Statements_Of_Cash_Flows

Statements Of Cash Flows (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities:
Net income	$91,428	$88,583	$90,846
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of electric plant in service	83,342	79,626	78,556
Amortization of nuclear fuel	43,864	42,537	42,953
Deferred income taxes, net	39,129	44,678	43,561
Allowance for equity funds used during construction	-14,662	-10,008	-9,427
Other amortization and accretion	18,380	16,556	14,724
Gain on sale of property, plant and equipment	-2,092	-112	-1,346
Net (gains) losses on sale of decommissioning trust funds	-7,350	-553	1,042
Other operating activities	-93	-260	-175
Change in:
Accounts receivable	-5,815	-2,450	13,448
Inventories	-786	-3,673	-1,926
Net over-collection (under-collection) of fuel revenues	-3,121	-10,843	11,668
Prepayments and other	-2,750	-4,295	-2,784
Accounts payable	9,684	8,180	1,725
Taxes accrued	-2,209	-627	-3,054
Other current liabilities	1,198	958	78
Deferred charges and credits	-4,807	-822	-6,781
Net cash provided by operating activities	243,340	247,475	273,108
Cash flows from investing activities:
Cash additions to utility property, plant and equipment	-277,078	-237,411	-202,387
Cash additions to nuclear fuel	-37,877	-30,535	-46,009
Capitalized interest and AFUDC:
Utility property, plant and equipment	-23,030	-16,063	-15,000
Nuclear fuel	-5,092	-5,299	-5,312
Allowance for equity funds used during construction	14,662	10,008	9,427
Decommissioning trust funds:
Purchases, including funding of $4.5 million	-117,675	-65,491	-107,705
Sales and maturities	108,311	56,148	98,542
Proceeds from sale of property, plant, and equipment	2,395	112	1,757
Other investing activities	4,192	5,767	633
Net cash used for investing activities	-331,192	-282,764	-266,054
Cash flows from financing activities:
Dividends paid	-44,556	-42,049	-38,889
Borrowings under the revolving credit facility:
Proceeds	231,399	44,883	234,575
Payments	-231,219	-52,686	-245,799
Pollution control bonds:
Proceeds	0	0	92,535
Payments	0	0	-92,535
Proceeds from issuance of senior notes	149,468	0	149,682
Other financing activities	-2,328	-324	-3,774
Net cash provided by (used for) financing activities	102,764	-50,176	95,795
Net increase (decrease) in cash and cash equivalents	14,912	-85,465	102,849
Cash and cash equivalents at beginning of period	25,592	111,057	8,208
Cash and cash equivalents at end of period	$40,504	$25,592	$111,057

Statements_of_Cash_Flows_Paren

Statements of Cash Flows Parenthetical (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Payments To Fund Decommissioning Fund	$4.50	$4.50	$4.50

Summary_of_Significant_Account

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Significant Accounting Policies	Summary of Significant Accounting Policies

	General. El Paso Electric Company is a public utility engaged in the generation, transmission and distribution of electricity in an area of approximately 10,000 square miles in west Texas and southern New Mexico. The Company also serves a full requirements wholesale customer in Texas.
	Basis of Presentation. The Company maintains its accounts in accordance with the Uniform System of Accounts prescribed by the Federal Energy Regulatory Commission (the "FERC").
	Use of Estimates. The preparation of financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
	Application of FASB Guidance for Regulated Operations. Regulated electric utilities typically prepare their financial statements in accordance with the Financial Accounting Standards Board ("FASB") guidance for regulated operations. FASB guidance for regulated operations requires the Company to include an allowance for equity and borrowed funds used during construction ("AEFUDC" and "ABFUDC") as a cost of construction of electric plant in service. AEFUDC is recognized as income and ABFUDC is shown as capitalized interest charges in the Company’s statement of operations. FASB guidance for regulated operations also requires the Company to show certain recoverable costs as either assets or liabilities on a utility’s balance sheet if the regulator provides assurance that these costs will be charged to and collected from the utility’s customers (or has already permitted such cost recovery) or will be credited or refunded to the utility’s customers. The resulting regulatory assets or liabilities are amortized in subsequent periods based upon the respective amortization periods reflected in a utility’s regulated rates. See Note D. The Company applies FASB guidance for regulated operations for all three of the jurisdictions in which it operates.
	Comprehensive Income. Certain gains and losses that are not recognized currently in the statements of operations are reported as other comprehensive income in accordance with FASB guidance for reporting comprehensive income.
	Utility Plant. Utility plant is generally reported at cost. The cost of renewals and betterments are capitalized and the costs of repairs and minor replacements are charged to the appropriate operating expense accounts. Depreciation is provided on a straight-line basis over the estimated remaining lives of the assets (ranging in average from 5 to 48 years). The average composite depreciation rate utilized in 2014, 2013 and 2012 was 2.60%, 2.61%, and 2.64%, respectively. When property subject to composite depreciation is retired or otherwise disposed of in the normal course of business, its cost – together with the cost of removal, less salvage – is charged to accumulated depreciation. For other property dispositions, the applicable cost and accumulated depreciation is removed from the balance sheet accounts and a gain or loss is recognized.
	The cost of nuclear fuel is amortized to fuel expense on a units-of-production basis. The Company is also amortizing its share of costs associated with on-site spent fuel storage casks at Palo Verde over the burn period of the fuel that will necessitate the use of the storage casks. See Note E.
	Impairment of Long-Lived Assets. Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated undiscounted future cash flows, an impairment charge is recognized for the amount by which the carrying amount of the asset exceeds the fair value of the asset.
	AFUDC and Capitalized Interest. The Company capitalizes interest ("ABFUDC") and common equity ("AEFUDC") costs to construction work in progress and capitalizes interest to nuclear fuel in process in accordance with the FERC Uniform System of Accounts as provided for in FASB guidance. AFUDC is a non-cash component of income and is calculated monthly and charged to all new eligible construction and capital improvement projects. AFUDC is compounded on a semi-annual basis. The AFUDC rates used in 2014, 2013 and 2012 were 8.15%, 8.10% and 8.53%, respectively.
	Asset Retirement Obligation. FASB guidance sets forth accounting requirements for the recognition and measurement of liabilities associated with the retirement of tangible long-lived assets. An asset retirement obligation ("ARO") associated with long-lived assets included within the scope of FASB guidance is that for which a legal obligation exists under enacted laws, statutes, written or oral contracts, including obligations arising under the doctrine of promissory estoppel and legal obligations to perform an asset retirement activity even if the timing and/or settlement are conditioned on a future event that may or may not be within the control of an entity. See Note F. Under FASB guidance, these liabilities are recognized as incurred if a reasonable estimate of fair value can be established and are capitalized as part of the cost of the related tangible long-lived assets. The Company records the increase in the ARO due to the passage of time as an operating expense (accretion expense).
	Cash and Cash Equivalents. All temporary cash investments with an original maturity of three months or less are considered cash equivalents.
	Investments. The Company’s marketable securities, included in decommissioning trust funds in the balance sheets, are reported at fair value and consist of cash, equity securities and municipal, federal and corporate bonds in trust funds established for decommissioning of its interest in Palo Verde. Such marketable securities are classified as "available-for-sale" securities and, as such, unrealized gains and losses are included in accumulated other comprehensive loss as a separate component of common stock equity. However, if declines in fair value of marketable securities below original cost basis are determined to be other than temporary, then the declines are reported as losses in the statement of operations and a new cost basis is established for the affected securities at fair value. Gains and losses are determined using the cost of the security based on the specific identification basis. See Note O.
	Derivative Accounting. Accounting for derivative instruments and hedging activities requires the recognition of derivatives as either assets or liabilities in the balance sheet with measurement of those instruments at fair value. Any changes in the fair value of these instruments are recorded in earnings or other comprehensive income. See Note O.
	Inventories. Inventories, primarily parts, materials, supplies, fuel oil and natural gas are stated at average cost not to exceed recoverable cost.
	Operating Revenues Net of Energy Expenses. The Company accrues revenues for services rendered, including unbilled electric service revenues. Energy expenses are stated at actual cost incurred. The Company’s Texas retail customers are billed under base rates and a fixed fuel factor approved by the Public Utility Commission of Texas ("PUCT"). The Company’s New Mexico retail customers are billed under base rates and a fuel adjustment clause which is adjusted monthly, as approved by the New Mexico Public Regulation Commission ("NMPRC"). The Company's FERC sales for resale customers are billed under formula base rates and fuel factors and a fuel adjustment clause which is adjusted monthly. The Company’s recovery of energy expenses is subject to periodic reconciliations of actual energy expenses incurred to actual fuel revenues collected. The difference between energy expenses incurred and fuel revenues charged to customers is reflected as over/under-collection of fuel revenues in the balance sheets. See Note C.
	Revenues. Revenues related to the sale of electricity are generally recorded when service is rendered or electricity is delivered to customers. The billing of electricity sales to retail customers is based on the reading of their meters, which occurs on a systematic basis throughout the month. Unbilled revenues are estimated based on monthly generation volumes and by applying an average revenue/kWh to the number of estimated kWhs delivered but not billed. Accounts receivable included accrued unbilled revenues of $21.2 million and $19.8 million at December 31, 2014 and 2013, respectively. The Company presents revenues net of sales taxes in its statements of operations.
	Allowance for Doubtful Accounts. The allowance for doubtful accounts represents the Company’s estimate of existing accounts receivable that will ultimately be uncollectible. The allowance is calculated by applying estimated write-off factors to various classes of outstanding receivables. The write-off factors used to estimate uncollectible accounts are based upon consideration of both historical collections experience and management’s best estimate of future collections success given the existing collections environment. Additions, deductions and balances for allowance for doubtful accounts for 2014, 2013 and 2012 are as follows (in thousands):




		2014		2013		2012
	Balance at beginning of year	$	2,261	$	2,906	$	3,015

	Additions:
	Charged to costs and expense	2,755		2,098		3,087

	Recovery of previous write-offs	1,516		1,929		2,041

	Uncollectible receivables written off	4,279		4,672		5,237

	Balance at end of year	$	2,253	$	2,261	$	2,906


	Income Taxes. The Company accounts for federal and state income taxes under the asset and liability method of accounting for income taxes. Deferred income taxes are recognized for the estimated future tax consequences of "temporary differences" by applying enacted statutory tax rates for each taxable jurisdiction applicable to future years to differences between the financial statement carrying amounts and the tax basis of existing assets and liabilities. Certain temporary differences are accorded flow-through treatment by the Company's regulators and impact the Company's effective tax rate. FASB guidance requires that rate-regulated companies record deferred income taxes for temporary differences accorded flow-through treatment at the direction of the regulatory commission. The resulting deferred tax assets and liabilities are recorded at the expected cash flow to be reflected in future rates. Because the Company's regulators have consistently permitted the recovery of tax effects previously flowed-through earnings, the Company has recorded regulatory liabilities and assets offsetting such deferred tax assets and liabilities. The effect on deferred tax assets and liabilities of a change in tax rate is recognized in income in the period that includes the enactment date. The Company recognizes tax assets and liabilities for uncertain tax positions in accordance with the recognition and measurement criteria of FASB guidance for uncertainty in income taxes. See Note J.
	Earnings per Share. The Company’s restricted stock awards are participating securities and earnings per share must be calculated using the two-class method in both the basic and diluted earnings per share calculations. For the basic earnings per share calculation, net income is allocated to the weighted average number of restricted stock awards and to the weighted average number of shares outstanding. The net income allocated to the weighted average number of shares outstanding is then divided by the weighted average number of shares outstanding to derive the basic earnings per share. For the diluted earnings per share, net income is allocated to the weighted average number of restricted stock awards and to the weighted average number of shares and dilutive potential shares outstanding. The Company’s dilutive potential shares outstanding amount is calculated using the treasury stock method for the unvested performance shares. Net income allocated to the weighted average number of shares and dilutive potential shares is then divided by the weighted average number of shares and dilutive potential shares outstanding to derive the diluted earnings per share. See Note G.
	Stock-Based Compensation. The Company has a stock-based long-term incentive plan. The Company is required under FASB guidance to measure the cost of employee services received in exchange for an award of equity instruments based on the grant-date fair value of the award. Such costs are recognized over the period during which an employee is required to provide service in exchange for the award (the "requisite service period") which typically is the vesting period. Compensation cost is not recognized for anticipated forfeitures prior to vesting of equity instruments. See Note G.
	Pension and Post-retirement Benefit Accounting. See Note M for a discussion of the Company’s accounting policies for its employee benefits.
	Reclassification. Certain amounts in the financial statements for 2013 and 2012 have been reclassified to conform with the 2014 presentation.

New_Accounting_Standards

New Accounting Standards	12 Months Ended
New Accounting Standards	Dec. 31, 2014
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]
New Accounting Pronouncements and Changes in Accounting Principles	New Accounting Standards
	In July 2013, the FASB issued new guidance (Accounting Standards Update ("ASU") 2013-11, Income Taxes (Topic 740)) to eliminate the diversity in the financial statement presentation of an unrecognized tax benefit when a net operating loss carryforward, a similar tax loss, or a tax credit carryforward exists. ASU 2013-11 requires an entity to present an unrecognized tax benefit in the financial statements as a reduction to a deferred tax asset for a net operating loss carryforward, a similar tax loss, or a tax credit carryforward, except in certain circumstances when it would be reflected as a liability. The Company implemented ASU 2013-11 in the first quarter of 2014 on a prospective basis. This ASU did not have a significant impact on the Company's statement of operations or statements of cash flows.
	In May 2014, the FASB issued new guidance (ASU 2014-09, Revenue from Contracts with Customers (Topic 606)) to provide a framework that replaces the existing revenue recognition guidance. ASU 2014-09 is the result of a joint effort by the FASB and the International Accounting Standards Board ("IASB") intended to clarify the principles for recognizing revenue and to develop a common revenue standard for U.S. Generally Accepted Accounting Principles ("GAAP") and International Financial Reporting Standards. ASU 2014-09 provides that an entity should recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. ASU 2014-09 is effective for annual periods and interim periods within that reporting period beginning after December 15, 2016, for public business entities. Early adoption of ASU 2014-09 is not permitted. The Company is currently assessing the future impact of this ASU.

Regulation

Regulation	12 Months Ended
	Dec. 31, 2014
Public Utilities, General Disclosures [Abstract]
Regulation	Regulation
	General
	The rates and services of the Company are regulated by incorporated municipalities in Texas, the PUCT, the NMPRC and the FERC. Municipal orders, ordinances and other agreements regarding rates and services adopted by Texas municipalities are subject to review and approval by the PUCT. The FERC has jurisdiction over the Company's wholesale (sales for resale) transactions, transmission service and compliance with federally-mandated reliability standards. The decisions of the PUCT, the NMPRC and the FERC are subject to judicial review.
	Texas Regulatory Matters
	2012 Texas Retail Rate Case. On April 17, 2012, the El Paso City Council approved the settlement of the Company's 2012 Texas retail rate case and fuel reconciliation in PUCT Docket No. 40094. The PUCT issued a final order approving the settlement on May 23, 2012 and rates were effective as of May 1, 2012. As part of the 2012 Texas retail rate settlement, the Company agreed to submit a future fuel reconciliation request covering the period beginning July 1, 2009 and ending no later than June 30, 2013 by December 31, 2013 or as part of its next rate case, if earlier. The Company filed a fuel reconciliation request covering the period July 1, 2009 through March 31, 2013, as discussed below. The 2012 Texas retail rate settlement also provided for the continuation of the energy efficiency cost recovery factor and the military base discount recovery factor. Both of these surcharges require annual filings to reconcile and revise the recovery factors.
	Energy Efficiency Cost Recovery Factor. The Company made its annual filing to establish its energy efficiency cost recovery factor for 2015 on May 1, 2014. In addition to projected energy efficiency costs for 2015 and true-up to prior year actual costs, the Company requested approval of a $2.0 million bonus for the 2013 energy efficiency program results in accordance with PUCT rules. In a proposal for decision issued on October 7, 2014, the Administrative Law Judge (“ALJ”) recommended approval of the Company’s requested cost recovery including the requested bonus. The PUCT approved the ALJ’s recommendation at its November 14, 2014 open meeting. The PUCT decision was not appealed. The Company recorded the $2.0 million bonus as operating revenue in the fourth quarter of 2014.
	Fuel and Purchased Power Costs. The Company's actual fuel costs, including purchased power energy costs, are recovered from customers through a fixed fuel factor. The PUCT has adopted a fuel cost recovery rule (the "Texas Fuel Rule") that allows the Company to seek periodic adjustments to its fixed fuel factor. The Company can seek to revise its fixed fuel factor based upon the approved formula at least four months after its last revision except in the month of December. The Texas Fuel Rule requires the Company to request to refund fuel costs in any month when the over-recovery balance exceeds a threshold material amount and it expects fuel costs to continue to be materially over-recovered. The Texas Fuel Rule also permits the Company to seek to surcharge fuel under-recoveries in any month the balance exceeds a threshold material amount and it expects fuel cost recovery to continue to be materially under-recovered. Fuel over and under-recoveries are considered material when they exceed 4% of the previous twelve months' fuel costs. All such fuel revenue and expense activities are subject to periodic final review by the PUCT in fuel reconciliation proceedings.
	On April 15, 2014, the Company filed a request, which was assigned PUCT Docket No. 42384, to increase its fixed fuel factor by $10.7 million or 6.9% annually, pursuant to its approved formula. The revised fixed fuel factor reflected an expected increase in prices for natural gas over the twelve month period beginning March 2014. The increase in the fixed fuel factor received final approval on May 28, 2014 and was effective with May 2014 billings. As of December 31, 2014, the Company had under-recovered fuel costs in the amount of $10.2 million for the Texas jurisdiction. The Company has been reducing the amount of the under-recovery since August 2014 and expects to continue to reduce the amount of under-recovery as long as the price of natural gas remains below the cost of natural gas included in its current fixed fuel factor. If the price of natural gas increases above the cost of natural gas included in the current fixed fuel factor, the Company may request an increase to the fixed fuel factor and effectively mitigate an increase in the under-recovery balance. If the under-recovered balance is above the materiality threshold at the time the fixed fuel factor increase is requested, then the Company will consider requesting a fuel surcharge to collect the remaining under-recovered balance.
	Fuel Reconciliation Proceeding. Pursuant to the 2012 Texas retail rate settlement discussed above, on September 27, 2013, the Company filed an application with the PUCT, designated as PUCT Docket No. 41852, to reconcile $545.3 million of fuel and purchased power expenses incurred during the 45-month period from July 1, 2009 through March 31, 2013. A settlement was reached and a final order was issued by the PUCT on July 11, 2014. The twelve months ended December 31, 2014 financial results include a $2.1 million, pre-tax increase to income reflecting the settlement of the Texas fuel reconciliation proceeding. The settlement included the recognition of $3.4 million of Palo Verde performance rewards associated with the 2009 to 2012 performance periods net of disallowed fuel and purchased power costs of $1.75 million of which $0.5 million had been previously reserved. Palo Verde performance rewards are not recognized in the Company’s financial results until the PUCT has ordered a final determination in a fuel proceeding or comparable evidence of collectability is obtained. In addition, the Company reimbursed the City of El Paso approximately $0.1 million in incurred expenses. The settlement also provides that 100% of margins on non-arbitrage off-system sales (as defined by the settlement) and 50% of margins on arbitrage off-system sales be shared with its Texas customers beginning April 1, 2014. For the period April 1, 2014 through June 30, 2015, the Company’s total share of margins assignable to Texas retail jurisdiction, on arbitrage and non-arbitrage off-system sales, may not exceed 10% of the total margins assignable to the Texas retail jurisdiction on all off-system sales. The Company also agreed to file with the PUCT a proceeding to address the reasonableness of the Company’s decision to not continue to participate in the Four Corners coal-fired generating Units 4 and 5 after July 2016. It is expected that issues related to the final coal mine closing and reclamation costs will be addressed in that proceeding as well as other issues related to post-participation events such as the asset retirement obligations of the Company related to those two units. The PUCT’s final order completes the regulatory review and reconciliation of the Company’s fuel expenses for the period through March 31, 2013.
	Montana Power Station Approvals. As discussed further below, the Company has received a Certificate of Convenience and Necessity ("CCN") from the PUCT to construct all four units of the Montana Power Station ("the MPS") in El Paso County, Texas. The Company also obtained air permits from the Texas Commission on Environmental Quality ("TCEQ") and the U.S. Environmental Protection Agency ("EPA").
	On June 23, 2014, the U.S. Supreme Court issued an opinion in the Utility Air Regulatory Group vs EPA regarding EPA’s authority to require greenhouse gas emissions ("GHG") Prevention of Significant Deterioration (“PSD”) permits for stationary sources. The opinion concluded that the EPA erred in making applicability of the Clean Air Act (“CAA”) permitting requirements based on GHG emissions. As a result, the Company believes its EPA air permit is no longer required and could be rescinded, and it is eligible for a standard air permit to replace the new source review permit issued by the TCEQ. Accordingly, on August 1, 2014, the Company submitted a request to the EPA to rescind the EPA air permit which request remains pending. Also, on September 16, 2014, the Company applied for a standard air permit, which TCEQ issued on October 2, 2014.
	On December 13, 2012, in PUCT Docket No. 40301, the Company received CCN approval from the PUCT for MPS Units 1 and 2. On September 6, 2013, the Company filed an application with the PUCT for issuance of a CCN to construct, own and operate two additional 88 MW natural gas-fired generating units designated as the MPS Units 3 and 4. The case was designated PUCT Docket No. 41763. Hearings in this case were held before an ALJ in February 2014. On July 11, 2014, the PUCT approved the CCN to construct MPS Units 3 and 4.
	In 2013, the Company filed three transmission line CCN applications with the PUCT as part of the MPS Project:


	•	MPS to Caliente: a 115-kV transmission line from the MPS to the existing Caliente Substation in east El Paso. (PUCT Docket No. 41360)

	•	MPS In & Out: a 115-kV transmission line from the MPS to intersect with the existing Caliente - Coyote 115-kV transmission line. (PUCT Docket No. 41359)

	•	MPS to Montwood: a 115-kV transmission line from the MPS to the existing Montwood Substation in east El Paso. (PUCT Docket No. 41809)
	The Company requested to build these transmission lines to connect the new MPS to the electrical grid in order to meet expected customer growth and electric demand and to improve system reliability. On March 10, 2014, the PUCT issued a final order approving a unanimous settlement in the MPS to Caliente transmission CCN filing. On August 18, 2014, the PUCT issued final orders approving unanimous settlements of the MPS In & Out transmission CCN filing and the MPS to Montwood transmission CCN filing.
	Other Required Approvals. The Company has obtained other required approvals for recovery of fuel costs through fixed fuel factors, other tariffs and approvals as required by the Public Utility Regulatory Act ( the "PURA") and the PUCT.
	New Mexico Regulatory Matters
	2009 New Mexico Stipulation. On December 10, 2009, the NMPRC issued a final order conditionally approving the stipulated rates in NMPRC Case No. 09-00171-UT. The stipulated rates went into effect with January 2010 bills. The stipulated rates provide for an Efficient Use of Energy Factor Rate Rider to recover energy efficiency expenditures which requires an annual filing and approval of the related incentives and adjustment to the recovery factors.
	Fuel and Purchased Power Costs. Fuel and purchased power costs are recovered through base rates and a Fuel and Purchased Power Cost Adjustment Clause (the "FPPCAC") that corrects for changes in the costs of fuel included in base rates. On January 8, 2014, the NMPRC approved the continuation of the FPPCAC without modification in NMPRC Case No. 13-00380-UT. Fuel and purchased power costs are reconciled to actual costs on a monthly basis and recovered or refunded to customers the second succeeding month. The Company recovers its investment in Palo Verde Unit 3 in New Mexico through the FPPCAC as purchased power using a proxy market price approved in the 2009 New Mexico rate stipulation.
	Montana Power Station Approvals. The Company has received a CCN from the NMPRC to construct all four units of the MPS and associated transmission lines. The Company also obtained all necessary air permits from the TCEQ and EPA and has begun construction. A final order in NMPRC Case No. 13-00297-UT approving the CCN for MPS Units 3 and 4 was issued on June 11, 2014.
	Other Required Approvals. The Company has obtained other required approvals for other tariffs, securities transactions, long-term resource plans, recovery of energy efficiency costs through a base rate rider and other approvals as required by the NMPRC.
	Federal Regulatory Matters
	Public Service Company of New Mexico's ("PNM") 2010 Transmission Rate Case. On October 27, 2010, PNM filed a Notice of Transmission Rate Change for transmission delivery services provided by PNM. These rates went into effect on June 1, 2011. The Company takes transmission service from PNM. On January 2, 2013, the FERC issued a letter order approving a unanimous stipulation and agreement. Pursuant to the stipulation, on January 31, 2013, PNM refunded $1.9 million for amounts that PNM collected since June 1, 2011 in excess of settlement rates. This amount was recorded in the fourth quarter of 2012 as a reduction of transmission expense.
	PNM Transmission Rate Case. On December 31, 2012, PNM filed with FERC to change its method of transmission rate recovery for its transmission delivery services from stated rates to formula rates. The Company takes transmission service from PNM and is among the PNM transmission customers affected by PNM’s shift to formula rates. On March 1, 2013, the FERC issued an order rejecting in part PNM’s filing, and establishing settlement judge and hearing procedures. The parties to the case, including the Company, have been participating in settlement negotiations. The Company cannot predict the outcome of the case at this time.
	Other Required Approvals. The Company has obtained required approvals for rates and tariffs, securities transactions and other approvals as required by the FERC.
	Department of Energy ("DOE"). The DOE regulates the Company's exports of power to the Comisión Federal de Electricidad in Mexico pursuant to a license granted by the DOE and two presidential permits.
	The DOE is authorized to assess operators of nuclear generating facilities a share of the costs of decommissioning the DOE's uranium enrichment facilities and for the ultimate costs of disposal of spent nuclear fuel. See Note E for discussion of spent fuel storage and disposal costs.
	Sales for Resale
	The Company provides firm capacity and associated energy to the Rio Grande Electric Cooperative ("RGEC") pursuant to an ongoing contract with a two-year notice to terminate provision. The Company also provides network integrated transmission service to the RGEC pursuant to the Company's Open Access Transmission Tariff ("OATT"). The contract includes a formula-based rate that is updated annually to recover non-fuel generation costs and a fuel adjustment clause designed to recover all eligible fuel and purchased power costs allocable to the RGEC.

Regulatory_Assets_and_Liabilit

Regulatory Assets and Liabilities	12 Months Ended
	Dec. 31, 2014
Regulatory Assets and Liabilities Disclosure [Abstract]
Schedule of Regulatory Assets and Liabilities	Regulatory Assets and Liabilities
	The Company's operations are regulated by the PUCT, the NMPRC and the FERC. Regulatory assets represent probable future recovery of previously incurred costs, which will be collected from customers through the ratemaking process. Regulatory liabilities represent probable future reductions in revenues associated with amounts that are to be credited to customers through the ratemaking process. Regulatory assets and liabilities reflected in the Company's balance sheets are presented below (in thousands):


		Amortization	December 31, 2014		December 31, 2013
		Period Ends
	Regulatory assets
	Regulatory tax assets (a)	(b)	$	66,134	$	61,772

	Loss on reacquired debt (c)	May-35	17,486		18,338

	Final coal reclamation (d)	(e)	10,702		4,290

	Nuclear fuel postload daily financing charge	(d)	4,127		4,141

	Unrecovered issuance costs due to reissuance of PCBs (c)	Aug-42	860		893

	Texas energy efficiency	(f)	1,817		—

	Texas 2012 rate case costs	Apr-14	—		581

	Texas 2015 rate case costs	(g)	169		—

	Texas military base discount and recovery factor	(h)	—		759

	New Mexico procurement plan costs	(g)	139		139

	New Mexico renewable energy credits	(g)	5,456		4,833

	New Mexico 2010 FPPCAC audit	(g)	434		433

	New Mexico Palo Verde deferred depreciation	(b)	4,720		4,871

	New Mexico 2015 rate case costs	(g)	42		—

	Total regulatory assets		$	112,086	$	101,050

	Regulatory liabilities
	Regulatory tax liabilities (a)	(b)	$	17,252	$	17,752

	Accumulated deferred investment tax credit (i)	(b)	4,334		4,656

	New Mexico energy efficiency	(f)	3,904		3,646

	Texas energy efficiency	(f)	—		362

	Texas military base discount and recovery factor	(h)	609		—

	Total regulatory liabilities		$	26,099	$	26,416


	________________

	(a)	No specific return on investment is required since related assets and liabilities offset.

	(b)	The amortization period for this asset is based upon the life of the associated assets or liabilities.

	(c)	This item is recovered as a component of the weighted cost of debt and amortized over the life of the related debt issuance.

	(d)	This item is recovered through fuel recovery mechanisms.

	(e)	This item and the related final coal reclamation liability have been included or will be requested in rate base.

	(f)	This item is recovered or credited through a recovery factor that is set annually.

(g)	Amortization period is anticipated to be established in next general rate case.

(h)	This item represents the net asset/net liability related to the military discount which is recovered from non-military customers through a recovery factor.

(i)	This item is excluded from rate base.

Utility_Plant_Palo_Verde_and_O

Utility Plant, Palo Verde and Other Jointly-Owned Utility Plant	12 Months Ended
	Dec. 31, 2014
Utility Plant, Palo Verde and Other Jointly-Owned Utility Plant [Abstract]
Schedule of Public Utility Property, Plant, and Equipment	Utility Plant, Palo Verde and Other Jointly-Owned Utility Plant
	The table below presents the balance of each major class of depreciable assets at December 31, 2014 (in thousands):




		Gross			Accumulated			Net
		Plant			Depreciation			Plant
	Nuclear production	$	874,817		$	(286,585	)	$	588,232

	Steam and other	684,863			(284,764		)	400,099

	Total production	1,559,680			(571,349		)	988,331

	Transmission	433,982			(250,941		)	183,041

	Distribution	1,020,901			(342,931		)	677,970

	General	139,491			(56,412		)	83,079

	Intangible	75,201			(45,039		)	30,162

	Total	$	3,229,255		$	(1,266,672	)	$	1,962,583

	Amortization of intangible plant (software) is provided on a straight-line basis over the estimated useful life of the asset (ranging from 5 to 10 years). The table below presents the actual and estimated amortization expense for intangible plant for the previous three years and for the next five years (in thousands):




	2012	7,183

	2013	7,683

	2014	8,051

	2015 (estimated)	7,505

	2016 (estimated)	7,030

	2017 (estimated)	6,388

	2018 (estimated)	4,762

	2019 (estimated)	3,101

	The Company owns a 15.8% interest in each of the three nuclear generating units and common facilities at Palo Verde, in Wintersburg, Arizona. The Palo Verde Participants include the Company and six other utilities: Arizona Public Service Company ("APS"), Southern California Edison Company ("SCE"), Public Service Company of New Mexico ("PNM"), Southern California Public Power Authority, Salt River Project Agricultural Improvement and Power District ("SRP") and the Los Angeles Department of Water and Power.
	Other jointly-owned utility plant includes a 7% interest in Units 4 and 5 at Four Corners Generating Station ("Four Corners") and certain other transmission facilities. A summary of the Company’s investment in jointly-owned utility plant, excluding fuel inventories, at December 31, 2014 and 2013 is as follows (in thousands):



		December 31, 2014						December 31, 2013
		Palo Verde			Other			Palo Verde			Other
	Electric plant in service	$	874,817		$	219,318		$	817,665		$	217,137

	Accumulated depreciation	(286,585		)	(176,492		)	(271,173		)	(173,819		)
	Construction work in progress	55,632			6,900			75,040			2,347

	Total	$	643,864		$	49,726		$	621,532		$	45,665

	Palo Verde
	The operation of Palo Verde and the relationship among the Palo Verde Participants is governed by the Arizona Nuclear Power Project Participation Agreement (the "ANPP Participation Agreement"). APS serves as operating agent for Palo Verde, and under the ANPP Participation Agreement, the Company has limited ability to influence operations and costs at Palo Verde. Pursuant to the ANPP Participation Agreement, the Palo Verde Participants share costs and generating entitlements in the same proportion as their percentage interests in the generating units, and each participant is required to fund its share of fuel, other operations, maintenance and capital costs. The Company’s share of direct expenses in Palo Verde and other jointly-owned utility plants is reflected in fuel expense, other operations expense, maintenance expense, miscellaneous other deductions, and taxes other than income taxes in the Company’s statements of operations. The ANPP Participation Agreement provides that if a participant fails to meet its payment obligations, each non-defaulting participant shall pay its proportionate share of the payments owed by the defaulting participant. Because it is impracticable to predict defaulting participants, the Company cannot estimate the maximum potential amount of future payment, if any, which could be required under this provision.
	NRC. The NRC regulates the operation of all commercial nuclear power reactors in the United States, including Palo Verde. The NRC periodically conducts inspections of nuclear facilities and monitors performance indicators to enable the agency to arrive at objective conclusions about a licensee’s safety performance.
	Palo Verde Operating Licenses. Operation of each of the three Palo Verde Units requires an operating license from the NRC. The NRC issued full power operating licenses for Unit 1 in June 1985, Unit 2 in April 1986 and Unit 3 in November 1987, and issued renewed operating licenses for each of the three units in April 2011, which extended the licenses for Units 1, 2 and 3 to June 2045, April 2046 and November 2047, respectively.
	Decommissioning. Pursuant to the ANPP Participation Agreement and federal law, the Company must fund its share of the estimated costs to decommission Palo Verde Units 1, 2 and 3, including the Common Facilities, through the term of their respective operating licenses and is required to maintain a minimum accumulation and funding level in its decommissioning account at the end of each annual reporting period during the life of the plant. The Company has established external trusts with an independent trustee, which enables the Company to record a current deduction for federal income tax purposes for most of the amounts funded. At December 31, 2014, the Company’s decommissioning trust fund had a balance of $234.3 million, which is above its minimum funding level. The Company monitors the status of its decommissioning funds and adjusts its deposits, if necessary.
Decommissioning costs are estimated every three years based upon engineering cost studies performed by outside engineers retained by APS. In December 2013, the Palo Verde Participants approved the 2013 Palo Verde decommissioning study (the "2013 Study"). The 2013 Study estimated that the Company must fund approximately $380.7 million (stated in 2013 dollars) to cover its share of decommissioning costs which was an increase in decommissioning costs of $23.3 million (stated in 2013 dollars) from the 2010 Palo Verde decommissioning study. However, because the cash flows from the 2013 Study were less than the inflated amounts from the 2010 Study, the effect of this change lowered the asset retirement obligation by $1.9 million which lowered annual expenses starting in January 2014. Although the 2013 Study was based on the latest available information, there can be no assurance that decommissioning cost estimates will not increase in the future or that regulatory requirements will not change. In addition, until a new low-level radioactive waste repository opens and operates for a number of years, estimates of the cost to dispose of low-level radioactive waste are subject to significant uncertainty.
Spent Nuclear Fuel and Waste Disposal. Pursuant to the Nuclear Waste Policy Act of 1982, as amended in 1987 (the "NWPA"), the DOE is legally obligated to accept and dispose of all spent nuclear fuel and other high-level radioactive waste generated by all domestic power reactors by 1998. The DOE's obligations are reflected in a contract for Disposal of Spent Nuclear Fuel and/or High-Level Radioactive Waste (the "Standard Contract") with each nuclear power plant. The DOE failed to begin accepting spent nuclear fuel by 1998. On December 19, 2012, APS, acting on behalf of itself and the participant owners of Palo Verde, filed a second breach of contract lawsuit against the DOE. This lawsuit sought to recover damages incurred due to the DOE’s failure to accept Palo Verde’s spent nuclear fuel for the period beginning January 1, 2007 through June 30, 2011. On August 18, 2014, APS and the DOE entered into a settlement agreement, stipulating to a dismissal of the lawsuit and payment of $57.4 million by the DOE to the Palo Verde owners for certain specified costs incurred by Palo Verde during the period January 1, 2007 through June 30, 2011. On October 8, 2014, the Company received approximately $9.1 million, representing its share of the award. The majority of the award was refunded to customers through the applicable fuel adjustment clauses. On October 31, 2014, APS acting on behalf of itself and the participant owners of Palo Verde, submitted to the government an additional request for reimbursement of spent nuclear fuel storage costs for the period July 1, 2011 through June 30, 2014. The total submitted claim amount was $42.5 million, of which the Company's portion is $6.7 million. The reimbursement is anticipated to be received in the first half of 2015, and the majority will be refunded to customers through the applicable fuel adjustment clauses.
DOE’s Construction Authorization Application for Yucca Mountain. The DOE had planned to meet its disposal obligations by designing, licensing, constructing, and operating a permanent geologic repository at Yucca Mountain, Nevada. In March 2010, the DOE filed a motion to dismiss with prejudice its Yucca Mountain construction authorization application that was pending before the NRC. Several interested parties have intervened in the NRC proceeding, and the proceeding has not been conclusively decided by the NRC or the courts. Additionally, a number of interested parties have filed a variety of lawsuits in different jurisdictions around the country challenging the DOE's authority to withdraw the Yucca Mountain construction authorization application and NRC’s cessation of its review of the Yucca Mountain construction authorization application. The cases have been consolidated into one matter at the U.S. Court of Appeals for the District of Columbia Circuit (the "D.C. Circuit"). In August 2013, the D.C. Circuit ordered the NRC to resume its review of the application with available appropriated funds.
On October 16, 2014, the NRC issued Volume 3 of the safety evaluation report developed as part of the Yucca Mountain construction authorization application. This volume addresses repository safety after permanent closure, and its issuance is a key milestone in the Yucca Mountain licensing process. Volume 3 contains the NRC staff’s finding that the DOE’s repository design meets the requirements that apply after the repository is permanently closed, including but not limited to the post-closure performance objectives in NRC’s regulations.
On December 18, 2014, the NRC issued Volume 4 of the safety evaluation report developed as part of the Yucca Mountain construction authorization application. This volume covers administrative and programmatic requirements for the repository. It documents the NRC staff’s evaluation of whether the DOE’s research and development and performance confirmation programs, as well as other administrative controls and systems, meet applicable NRC requirements. Volume 4 contains the NRC staff’s finding that most administrative and programmatic requirements in NRC regulations are met, except for certain requirements relating to ownership of land and water rights.
Publication of Volumes 3 and 4 does not signal whether or when the NRC might authorize construction of the repository. The Company cannot predict when spent fuel shipments to the DOE will commence.
Waste Confidence. On June 8, 2012, the D.C. Circuit issued its decision on a challenge by several states and environmental groups of the NRC’s rulemaking regarding temporary storage and permanent disposal of high level nuclear waste and spent nuclear fuel. The petitioners had challenged the NRC’s 2010 update to the agency’s Waste Confidence Decision and temporary storage rule (“Waste Confidence Decision”).
The D.C. Circuit found that the agency’s 2010 Waste Confidence Decision update constituted a major federal action, which, consistent with the National Environmental Policy Act (“NEPA”), requires either an environmental impact statement or a finding of no significant impact from the agency’s actions. The D.C. Circuit found that the NRC’s evaluation of the environmental risks from spent nuclear fuel was deficient, and therefore remanded the 2010 Waste Confidence Decision update for further action consistent with NEPA.
On September 6, 2012, the NRC Commissioners issued a directive to the NRC staff to proceed directly with development of a generic environmental impact statement to support an updated Waste Confidence Decision. The NRC Commissioners also directed the NRC staff to establish a schedule to publish a final rule and environmental impact study within 24 months of September 6, 2012.
In September 2013, the NRC issued its draft Generic Environmental Impact Statement (“GEIS”) to support an updated Waste Confidence Decision. On August 26, 2014, the NRC approved a final rule on the environmental effects of continued storage of spent nuclear fuel. The continued storage rule adopted the findings of the GEIS regarding the environmental impacts of storing spent fuel at any reactor site after the reactor’s licensed period of operations. As a result, those generic impacts do not need to be re-analyzed in the environmental reviews for individual licenses. Although Palo Verde had not been involved in any licensing actions affected by the D.C. Circuit’s June 8, 2012, decision, the NRC lifted its suspension on final licensing actions on all nuclear power plant licenses and renewals that went into effect when the D.C. Circuit issued its June 2012 decision. The August 24 final rule has been subject to continuing legal challenges before the NRC and the Court of Appeals.
Palo Verde has sufficient capacity at its on-site independent spent fuel storage installation (“ISFSI”) to store all of the nuclear fuel that will be irradiated during the initial operating license period, which ends in December 2027. Additionally, Palo Verde has sufficient capacity at its on-site ISFSI to store a portion of the fuel that will be irradiated during the period of extended operation, which ends in November 2047. If uncertainties regarding the United States government’s obligation to accept and store spent fuel are not favorably resolved, APS will evaluate alternative storage solutions that may obviate the need to expand the ISFSI to accommodate all of the fuel that will be irradiated during the period of extended operation.
The One-Mill Fee. In 2011, the National Association of Regulatory Utility Commissioners and the Nuclear Energy Institute challenged DOE’s 2010 determination of the adequacy of the one tenth of a cent per kWh fee (the "one-mill fee") paid by the nation’s commercial nuclear power plant owners pursuant to their individual obligations under the Standard Contract. This fee was recovered by the Company through applicable fuel adjustment clauses. In June 2012, the D.C. Circuit held that DOE failed to conduct a sufficient fee analysis in making the 2010 determination. The D.C. Circuit remanded the 2010 determination to the Secretary of the DOE ("Secretary") with instructions to conduct a new fee adequacy determination within six months. In February 2013, upon completion of DOE’s revised one-mill fee adequacy determination, the court reopened the proceedings. On November 19, 2013, the D.C. Circuit ordered the Secretary to notify Congress of his intent to suspend collecting annual fees for nuclear waste disposal from nuclear power plant operators, as he is required to do pursuant to the NWPA and the court’s order. On January 3, 2014, the Secretary notified Congress of his intention to suspend collection of the one-mill fee, subject to Congress’ disapproval and on May 12, 2014, APS was notified by the DOE that, effective May 16, 2014, the one-mill fee would be suspended. Electricity generated and sold prior to May 16, 2014 remained subject to the one-mill fee.
NRC Oversight of the Nuclear Energy Industry in the Wake of the Earthquake and Tsunami in Japan. The NRC regulates the operation of all commercial nuclear power reactors in the United States, including Palo Verde. The NRC periodically conducts inspections of nuclear facilities and monitors performance indicators to enable the agency to arrive at objective conclusions about a licensee's safety performance. Following the March 11, 2011 earthquake and tsunami in Japan, the NRC established a task force to conduct a systematic and methodical review of NRC processes and regulations to determine whether the agency should make additional improvements to its regulatory system. On March 12, 2012, the NRC issued the first regulatory requirements based on the recommendations of the NRC's Near Term Task Force. With respect to Palo Verde, the NRC issued two orders requiring safety enhancements regarding: (1) mitigation strategies to respond to extreme natural events resulting in the loss of power at plants; and (2) enhancement of spent fuel pool instrumentation.
The NRC has issued a series of interim staff guidance documents regarding implementation of these requirements. Due to the developing nature of these requirements, the Company cannot predict the ultimate financial or operational impacts on Palo Verde or the Company; however, the NRC has directed nuclear power plants to implement the first tier recommendations of the NRC’s Near Term Task Force. In response to these recommendations, Palo Verde expects to spend approximately $40 million for capital enhancements to the plant over the next two years (the Company's share is $6.3 million) in addition to the approximate $80 million (the Company’s share is $12.6 million) that has already been spent on capital enhancements as of December 31, 2014.
Liability and Insurance Matters. The Palo Verde Participants have insurance for public liability resulting from nuclear energy hazards to the full limit of liability under federal law, which is currently at $13.6 billion. This potential liability is covered by primary liability insurance provided by commercial insurance carriers in the amount of $375 million, and the balance is covered by an industry-wide retrospective assessment program. If a loss at a nuclear power plant covered by the programs exceeds the accumulated funds in the primary level of protection, the Company could be assessed retrospective premium adjustments on a per incident basis. Under federal law, the maximum assessment per reactor under the program for each nuclear incident is approximately $127.3 million, subject to an annual limit of $19.0 million. Based upon the Company's 15.8% interest in the three Palo Verde units, the Company's maximum potential assessment per incident for all three units is approximately $60.4 million, with an annual payment limitation of approximately $9.0 million.
The Palo Verde Participants maintain $2.8 billion of "all risk" nuclear property insurance. The insurance provides coverage for property damage and decontamination at Palo Verde. For covered incidents involving property damage not accompanied by a release of radioactive material, the policy's coverage limit is $2.3 billion. The Company has also secured insurance against portions of any increased cost of generation or purchased power and business interruption resulting from a sudden and unforeseen outage of any of the three units. The insurance coverage discussed in this and the previous paragraph is subject to certain policy conditions and exclusions. A mutual insurance company whose members are utilities with nuclear facilities issues these policies. If losses at any nuclear facility covered by this mutual insurance company were to exceed the accumulated funds for these insurance programs, the Company could be assessed retrospective premium adjustments of up to $10.9 million for the current policy period.

Four Corners
The Company owns a 7% interest in Units 4 and 5 at Four Corners and shares power entitlements and allocated costs with APS, the operating agent, and the other Four Corners participants. The Company notified the other participants in 2013 that it would not continue in Four Corners after the termination of the 50-year contractual term of the participation agreement but that it would offer to sell its interest to them in order to facilitate their decision to extend the life of the plant. On February 17, 2015, the Company and APS entered into an asset purchase agreement (the “Agreement”), providing for the purchase by APS of the Company’s interests in Four Corners. The cash purchase price is equal to the net book value of the Company’s interest in Four Corners at the date of closing, which is expected to occur not later than July 2016, subject to the receipt of regulatory approvals. The purchase price will be adjusted downward to reflect APS’s assumption in the Agreement of the Company’s obligation to pay for future plant decommissioning and mine reclamation expenses. At the closing, APS will also reimburse the Company for the undepreciated value of certain capital expenditures made prior thereto. APS will assume responsibility for all capital expenditures made after July 2016 and, with certain exceptions, any pre-2016 capital expenditures to be put into service following the closing. In addition, APS will indemnify the Company against liabilities and costs related to the future operation of Four Corners. Included in the Company's balance sheet at December 31, 2014 are obligations of $6.1 million and $19.3 million for plant decommissioning and mine reclamation costs, respectively, which the Company expects to pay at closing in accordance with the Agreement.

Accounting_for_Asset_Retiremen

Accounting for Asset Retirement Obligations	12 Months Ended
	Dec. 31, 2014
Accounting for Asset Retirement Obligations
Asset Retirement Obligation Disclosure	Accounting for Asset Retirement Obligations
	The Company complies with FASB guidance for asset retirement obligations ("ARO"). This guidance affects the accounting for the decommissioning of the Company’s Palo Verde and Four Corners Stations and the method used to report the decommissioning obligation. The Company also complies with FASB guidance for conditional asset retirement obligations which primarily affects the accounting for the disposal obligations of the Company’s fuel oil storage tanks, water wells, evaporative ponds and asbestos found at the Company’s gas-fired generating plants. The Company’s AROs are subject to various assumptions and determinations such as: (i) whether a legal obligation exists to remove assets; (ii) estimation of the fair value of the costs of removal; (iii) when final removal will occur; (iv) future changes in decommissioning cost escalation rates; and (v) the credit-adjusted interest rates to be utilized in discounting future liabilities. Changes that may arise over time with regard to these assumptions and determinations will change amounts recorded in the future as an expense for AROs. The Company records the increase in the ARO due to the passage of time as an operating expense (accretion expense). If the Company incurs or assumes any liability in retiring any asset at the end of its useful life without a legal obligation to do so, it will record such retirement costs as incurred.
	The ARO liability for Palo Verde is based upon the estimated cost of decommissioning the plant from the 2013 Palo Verde decommissioning study. See Note E. The ARO liability is calculated by adjusting the estimated decommissioning costs for spent fuel storage and a profit margin and market-risk premium factor. The resulting costs are escalated over the remaining life of the plant and finally discounted using a credit-risk adjusted discount rate. As Palo Verde approaches the end of its estimated useful life, the difference between the ARO liability and future current cost estimates will narrow over time due to the accretion of the ARO liability. Because the DOE is obligated to assume responsibility for the permanent disposal of spent fuel, spent fuel costs have not been included in the ARO calculation. The Company maintains six external trust funds with an independent trustee that are legally restricted to settling its ARO at Palo Verde. The fair value of the funds at December 31, 2014 is $234.3 million.
	FASB guidance requires the Company to revise its previously recorded ARO for any changes in estimated cash flows including changes in estimated probabilities related to timing of settlements. Any changes that result in an upward revision to estimated cash flows shall be treated as a new liability. Any downward revisions to the estimated cash flows result in a reduction to the previously recorded ARO. In December 2013, the Company implemented the 2013 Palo Verde decommissioning study, and as a result, revised its ARO related to Palo Verde to decrease its estimated cash flows from the 2010 Study to the 2013 Study (see Note E). The assumptions used to calculate the Palo Verde ARO liability are as follows:



		Escalation		Credit-Risk
		Rate		Adjusted
				Discount Rate
	Original ARO liability	3.6	%	9.5	%
	Incremental ARO liability	3.6	%	6.2	%
	A roll forward of the Company’s total ARO liability from January 1, 2012 through December 31, 2014, including the effects of each year’s estimate revisions, is presented below. In 2014, the estimate revision includes an adjustment to Four Corners due to the early recognition of the obligation resulting from the purchase agreement with APS. In 2013, the estimate revision includes a change to the probability of extending Four Corners’ operating term and decreases in the estimated cash flows related to Palo Verde’s decommissioning due to implementing the 2013 Palo Verde decommissioning study. In 2012, the estimate revision includes a change to the probability of extending Four Corners’ operating term.



		2014			2013			2012
	ARO liability at beginning of year	$	65,214		$	62,784		$	56,140

	Liabilities incurred	—			—			—

	Liabilities settled	—			(36		)	(450		)

	Revisions to estimate	3,561			(3,401		)	1,929

	Accretion expense	5,802			5,867			5,165

	ARO liability at end of year	$	74,577		$	65,214		$	62,784


	The Company has transmission and distribution lines which are operated under various property easement agreements. If the easements were to be released, the Company may have a legal obligation to remove the lines; however, the Company has assessed the likelihood of this occurring as remote. The majority of these easements include renewal options which the Company routinely exercises.

Common_Stock_Notes

Common Stock (Notes)	12 Months Ended
	Dec. 31, 2014
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shareholders' Equity and Share-based Payments , Including Earnings Per Share Information	Common Stock
	Overview
	The Company’s common stock has a stated value of $1 per share, with no cumulative voting rights or preemptive rights. Holders of the common stock have the right to elect the Company’s directors and to vote on other matters.
	Long-Term Incentive Plan
	On May 29, 2014, the Company’s shareholders approved an amended and restated stock-based long-term incentive plan (the "Amended and Restated 2007 LTIP") and authorized the issuance of up to 1.7 million shares of common stock for the benefit of directors and employees. Under the Amended and Restated 2007 LTIP, common stock may be issued through the award or grant of non-statutory stock options, incentive stock options, stock appreciation rights, restricted stock, bonus stock, performance stock, cash-based awards and other stock-based awards. The Company may issue new shares, purchase shares on the open market, or issue shares from shares the Company has repurchased to meet the share requirements of the Amended and Restated 2007 LTIP. As discussed in Note A, the Company accounts for its stock-based long-term incentive plan under FASB guidance for stock-based compensation.
	Stock Options. Stock options have been granted at exercise prices equal to or greater than the market value of the underlying shares at the date of grant. The fair value for these options was estimated at the grant date using the Black-Scholes option pricing model. The options expired ten years from the date of grant unless terminated earlier by the Board of Directors (the “Board”). Stock options have not been granted since 2003.
	The 15,000 options outstanding at December 31, 2012 were exercised during 2013 with a weighted average exercise price of $12.78. The Company received $0.2 million in cash and realized a current tax benefit of $0.1 million. The Company had no stock options outstanding as of December 31, 2013 and December 31, 2014.
	The intrinsic value of stock options exercised in 2013 and 2012 were $0.3 million and $0.6 million, respectively. No options were forfeited, vested or expired during 2014, 2013 and 2012. No compensation cost was recognized in 2014, 2013 and 2012 for stock options.
	Restricted Stock and Other Stock-Based Awards. The Company has awarded restricted stock and other stock-based awards under its long-term incentive plan. Restrictions from resale on restricted stock awards generally lapse and awards vest over periods of one to three years. The market value of the unvested restricted stock at the date of grant is amortized to expense over the restriction period net of anticipated forfeitures.
	Other stock-based awards are fully vested and are expensed at fair value on the date of grant. Previously directors could elect to receive retainers and meeting fees in cash, restricted stock, or a combination of cash and stock. On May 29, 2014, the Board of Directors voted to revise the terms of the restricted stock awards granted to directors in lieu of cash for retainers and meeting fees. Stock elections by directors in lieu of cash for retainer and meeting fees are now fully vested and are expensed at fair value on the date of grant. The modification to 13,863 outstanding restricted stock awards granted to directors resulted in forfeiture of those awards and the granting of new awards which were fully vested and expensed at $37.81 per share, the fair value on the date of grant.
	The expense, deferred tax benefit, and current tax expense recognized related to restricted stock awards and other stock-based awards in 2014, 2013 and 2012 is presented below (in thousands):


			2014				2013				2012

	Expense (a)		$	3,471			$	2,458			$	1,508

	Deferred tax benefit		1,215				860				528

	Current tax benefit recognized		39				109				94

	_____________________
	(a) Any capitalized costs related to these expenses is less than $0.1 million for all years.
	The aggregate intrinsic value and fair value at grant date of restricted stock and other stock-based awards which vested in 2014, 2013 and 2012 is presented below (in thousands):


			2014				2013				2012

	Aggregated intrinsic value		$	3,441			$	2,077			$	2,242

	Fair value at grant date		3,330				1,765				1,973

	The unvested restricted stock and other stock-based award transactions for 2014 are presented below:


		Total			Weighted				Unrecognized Compensation Expense (a)				Aggregate Intrinsic Value
		Shares			Average
					Grant Date
					Fair Value
									(In thousands)				(In thousands)
	Restricted shares outstanding at December 31, 2013	120,534			$	35.19

	Stock awards	113,776			36.95

	Vested	(90,851	)		36.66

	Forfeitures	(19,162	)		34.72

	Restricted shares outstanding at December 31, 2014	124,297			35.81				$	1,662			$	4,979

	_______________________
	(a) The unrecognized compensation expense is expected to be recognized over the weighted average remaining contractual term of the outstanding restricted stock of approximately one year.
	The weighted average fair value per share at grant date for restricted stock and other stock-base awards granted during 2014, 2013 and 2012 were:


		2014				2013				2012
	Weighted average fair value per share	$	36.95			$	35.48			$	32.45

	The holder of a restricted stock award has rights as a shareholder of the Company, including the right to vote and receive cash dividends on restricted stock.
	Performance Shares. The Company has granted performance share awards to certain officers under the Company’s Amended and Restated 2007 LTIP, which provides for issuance of Company stock based on the achievement of certain performance criteria over a three-year period. The payout varies between 0% to 200% of performance share awards.
	Detail of performance shares vested follows:


	Date Vested		Payout Ratio			Performance Shares Awarded			Compensation Costs Expensed				Period Compensation Costs Expensed		Aggregated Intrinsic Value
								(In thousands)						(In thousands)
February 20, 2015		0	%		0			$	1,502			2012-2014		$	—

February 18, 2014		0	%		0			954				2011-2013		—

January 29, 2013		150	%		64,275			849				2010-2012		2,176

January 1, 2012		175	%		174,038			1,193				2009-2011		6,029

In 2015, 2016 and 2017, subject to meeting certain performance criteria, additional performance shares could be awarded. In accordance with FASB guidance related to stock-based compensation, the Company recognizes the related compensation expense by ratably amortizing the grant date fair value of awards over the requisite service period and the compensation expense is only adjusted for forfeitures. The actual number of shares to be issued can range from zero to 145,496 shares.
The fair value at the date of each separate grant of performance shares was based upon a Monte Carlo simulation. The Monte Carlo simulation reflected the structure of the performance plan which calculates the share payout on performance of the Company relative to a defined peer group over a three-year performance period based upon total return to shareholders. The fair value was determined as the average payout of one million simulation paths discounted to the grant date using a risk-free interest rate based upon the constant maturity treasury rate yield curve at the grant date. The expected volatility of total return to shareholders is calculated in accordance with the plan’s term structure and includes the volatilities of all members of the defined peer group.
The outstanding performance share awards at the 100% performance level is summarized below:


	Number			Weighted				Unrecognized Compensation Expense (a)				Aggregate Intrinsic Value
	Outstanding			Average
				Grant Date
				Fair Value
								(In thousands)				(In thousands)
Performance shares outstanding at December 31, 2013	124,997			$	31.38

Performance share awards	37,561			26.36

Performance shares lapsed	(34,050	)		28.03

Performance shares forfeited	(7,027	)		32.24

Performance shares outstanding at December 31, 2014	121,481			30.71				$	975			$	4,867

_______________________
(a) The unrecognized compensation expense is expected to be recognized over the weighted average remaining contractual term of the awards of approximately one year.

A summary of information related to performance shares for 2014, 2013 and 2012 is presented below:


	2014				2013				2012
Weighted average per share grant date fair value per share of performance shares awarded	$	26.36			$	34.69			$	32.74

Fair value of performance shares vested (in thousands)	—				849				1,193

Intrinsic value of performance shares vested (in thousands) (a)	—				1,450				3,464

Compensation expense (in thousands) (b)	1,181				1,188				170

Deferred tax benefit related to compensation expense (in thousands)	413				416				59

_____________________
(a) Based on a 100% performance level.
(b) Includes adjustments for forfeiture of performance share awards by certain executives.
Repurchase Program
No shares of common stock were repurchased during the twelve months ended December 31, 2014. Detail regarding the Company's stock repurchase program are presented below:


	Since 1999				Authorized
	(a)				Shares
Shares repurchased (b)	25,406,184

Cost, including commission (in thousands)	$	423,647

Total remaining shares available for repurchase at December 31, 2014					393,816

______________________

(a)	Represents repurchased shares and cost since inception of the stock repurchase program in 1999.

(b)	Shares repurchased does not include 86,735 treasury shares related to employee compensation arrangements outside of the Company's repurchase programs.
The Company may in the future make purchases of its common stock pursuant to its authorized program in open market transactions at prevailing prices and may engage in private transactions where appropriate. The repurchased shares will be available for issuance under employee benefit and stock incentive plans, or may be retired.
Dividend Policy
On December 30, 2014, the Company paid $11.3 million in quarterly cash dividends to shareholders. The Company paid a total of $44.6 million, $42.0 million and $38.9 million in cash dividends during the twelve months ended December 31, 2014, 2013 and 2012, respectively. On January 29, 2015, the Board of Directors declared a quarterly cash dividend of $0.28 per share payable on March 31, 2015 to shareholders of record on March 16, 2015.
Basic and Diluted Earnings Per Share
FASB guidance requires the Company to include share-based compensation awards that qualify as participating securities in both basic and diluted earnings per share to the extent they are dilutive. A share-based compensation award is considered a participating security if it receives non-forfeitable dividends or may participate in undistributed earnings with common stock. The Company awards unvested restricted stock which qualifies as a participating security. The basic and diluted earnings per share are presented below:


	Years Ended December 31,
	2014				2013				2012
Weighted average number of common shares outstanding:
Basic number of common shares outstanding	40,190,991				40,114,594				39,974,022

Dilutive effect of unvested performance awards	20,726				12,053				66,756

Dilutive effect of stock options	—				—				14,803

Diluted number of common shares outstanding	40,211,717				40,126,647				40,055,581

Basic net income per common share:
Net income	$	91,428			$	88,583			$	90,846

Income allocated to participating restricted stock	(301		)		(254		)		(256		)
Net income available to common shareholders	$	91,127			$	88,329			$	90,590

Diluted net income per common share:
Net income	$	91,428			$	88,583			$	90,846

Income reallocated to participating restricted stock	(301		)		(254		)		(256		)
Net income available to common shareholders	$	91,127			$	88,329			$	90,590

Basic net income per common share:
Distributed earnings	$	1.105			$	1.045			$	0.97

Undistributed earnings	1.165				1.155				1.3

Basic net income per common share	$	2.27			$	2.2			$	2.27

Diluted net income per common share:
Distributed earnings	$	1.105			$	1.045			$	0.97

Undistributed earnings	1.165				1.155				1.29

Diluted net income per common share	$	2.27			$	2.2			$	2.26

The amount of restricted stock awards and performance shares at 100% performance level excluded from the calculation of the diluted number of common shares outstanding because their effect was antidilutive is presented below:


		Year Ended December 31,
		2014			2013			2012
Restricted stock awards		60,455			51,489			45,178

Performance shares (a)		96,208			115,044			57,625

_____________________

(a)	Certain performance shares were excluded from the computation of diluted earnings per share as no payouts would have been required based upon performance at the end of each corresponding period.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Income (Notes)	12 Months Ended
	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Comprehensive Income (Loss) Note	Accumulated Other Comprehensive Income (Loss)



	Changes in Accumulated Other Comprehensive Income (Loss) (net of tax) by component are presented below (in thousands):
			Unrecognized Pension and Post-retirement Benefit Costs				Net Unrealized Gains (Losses) on Marketable Securities				Net Losses on Cash Flow Hedges			Accumulated Other Comprehensive Income (Loss)

	Balance at December 31, 2012		$	(75,737	)		$	22,194			$	(12,541	)	$	(66,084	)

		Other comprehensive income before reclassifications	51,371				14,482				—			65,853

		Amounts reclassified from accumulated other comprehensive income (loss)	3,036				(436		)		243			2,843

	Balance at December 31, 2013		(21,330		)		36,240				(12,298		)	2,612

		Other comprehensive income (loss) before reclassifications	(12,628		)		8,694				—			(3,934		)

		Amounts reclassified from accumulated other comprehensive income (loss)	(926		)		(5,977		)		224			(6,679		)

	Balance at December 31, 2014		$	(34,884	)		$	38,957			$	(12,074	)	$	(8,001	)



	Amounts reclassified from accumulated other comprehensive income (loss) for the twelve months ended December 31, 2014 and 2013 are as follows ( in thousands):


	Details about Accumulated Other Comprehensive Income (Loss) Components			2014				2013				Affected Line Item in the Statement of Operations

	Amortization of pension and post-retirement benefit costs:
		Prior service benefit		$	7,659			$	5,560			(a)

		Net loss		(6,182		)		(10,472		)		(a)
				1,477				(4,912		)		(a)

		Income tax effect		(551		)		1,876

				926				(3,036		)		(a)


	Marketable securities:
		Net realized gain on sale of securities		7,350				553				Investment and interest income, net

				7,350				553				Income before income taxes

		Income tax effect		(1,373		)		(117		)		Income tax expense
				5,977				436				Net income


	Loss on cash flow hedge:
		Amortization of loss		(438		)		(411		)		Interest on long-term debt and RCF
				(438		)		(411		)		Income before income taxes
		Income tax effect		214				168				Income tax expense

				(224		)		(243		)		Net income

		Total reclassifications		$	6,679			$	(2,843	)


	(a) These items are included in the computation of net periodic benefit cost. See Note M, Employee Benefits, for additional information.

LongTerm_Debt_and_Financing_Ob

Long-Term Debt and Financing Obligations (Notes)	12 Months Ended
	Dec. 31, 2014
Long-Term Debt and Financing Obligations [Abstract]
Long-term Debt	Long-Term Debt and Financing Obligations
	Outstanding long-term debt and financing obligations are as follows:


		December 31,
		2014			2013
		(In thousands)
	Long-Term Debt:
	Pollution Control Bonds (1):
	7.25% 2009 Series A refunding bonds, due 2040 (7.46% effective interest rate)	$	63,500		$	63,500

	4.50% 2012 Series A refunding bonds, due 2042 (4.63% effective interest rate)	59,235			59,235

	7.25% 2009 Series B refunding bonds, due 2040 (7.49% effective interest rate)	37,100			37,100

	1.875% 2012 Series A refunding bonds, due 2032 (2.35% effective interest rate)	33,300			33,300

	Total Pollution Control Bonds	193,135			193,135

	Senior Notes (2):
	6.00% Senior Notes, net of discount, due 2035 (7.12% effective interest rate)	398,021			397,976

	7.50% Senior Notes, net of discount, due 2038 (7.67% effective interest rate)	148,818			148,800

	3.30% Senior Notes, net of discount, due 2022 (3.43% effective interest rate)	149,737			149,709

	5.00% Senior Notes, net of discount, due 2044 (5.10% effective interest rate)	149,468			—

	Total Senior Notes	846,044			696,485

	RGRT Senior Notes (3):
	3.67% Senior Notes, Series A, due 2015 (3.87% effective interest rate)	15,000			15,000

	4.47% Senior Notes, Series B, due 2017 (4.62% effective interest rate)	50,000			50,000

	5.04% Senior Notes, Series C, due 2020 (5.16% effective interest rate)	45,000			45,000

	Total RGRT Senior Notes	110,000			110,000

	Total long-term debt	1,149,179			999,620

	Financing Obligations:
	Revolving Credit Facility ($14,532 due in 2015) (4)	14,532			14,352

	Total long-term debt and financing obligations	1,163,711			1,013,972

	Current Portion (amount due within one year):
	Current maturities of long term debt	(15,000		)	—

	Short-term borrowings under the revolving credit facility	(14,532		)	(14,352		)
		$	1,134,179		$	999,620

	_____________________

	-1	Pollution Control Bonds ("PCBs")

	The Company has four series of tax exempt unsecured PCBs in aggregate principal amount of $193.1 million. The 1.875% 2012 Series A (El Paso Electric Company Four Corners Project) Pollution Control Refunding Revenue Bonds with an aggregate principal amount of $33.3 million are subject to mandatory tender for purchase in September 2017.


	-2	Senior Notes

	The Senior Notes are unsecured obligations of the Company. They were issued pursuant to bond covenants that provide limitations on the Company’s ability to enter into certain transactions. The 6.00% Senior Notes have an aggregate principal amount of $400.0 million and were issued in May 2005. The proceeds, net of a $2.3 million discount, were used to fund the retirement of the Company's first mortgage bonds. The Company amortizes the loss associated with a cash flow hedge recorded in accumulated other comprehensive income to earnings as interest expense over the life of the 6.00% Senior Notes. See Note O, "Financial Instruments and Investments - Treasury Rate Locks". This amortization is included in the effective interest rate of the 6.00% Senior Notes.

	The 7.50% Senior Notes have an aggregate principal amount of $150.0 million and were issued in June 2008. The proceeds, net of a $1.3 million discount, were used to repay short-term borrowings of $44.0 million, fund capital expenditures and for other general corporate purposes.

The 3.30% Senior Notes have an aggregate principal amount of $150.0 million and were issued in December 2012. The proceeds, net of a $0.3 million discount, were used to fund construction expenditures and for working capital and general corporate purposes.

The 5.00% Senior Notes have an aggregate principal amount of $150.0 million and were issued in December 2014. The proceeds, net of a $0.5 million discount, were used to fund construction expenditures and for working capital and general corporate purposes.


-3	RGRT Senior Notes

In 2010, the Company and RGRT, a Texas grantor trust through which the Company finances its portion of fuel for Palo Verde, entered into a note purchase agreement with various institutional purchasers. Under the terms of the agreement, RGRT sold to the purchasers $110 million aggregate principal amount of Senior Notes (the "Notes") of which $15.0 million will mature in August 2015. The Company will either repay or refinance this $15.0 million of Notes upon maturity. The Company guarantees the payment of principal and interest on the Notes. In the Company’s financial statements, the assets and liabilities of the RGRT are reported as assets and liabilities of the Company.

RGRT pays interest on the Notes on February 15, and August 15 of each year until maturity. RGRT may redeem the Notes, in whole or in part, at any time at a redemption price equal to 100% of the principal amount to be redeemed together with the interest on such principal amount accrued to the date of redemption, plus a make-whole amount based on the prevailing market interest rates. The agreement requires compliance with certain covenants, including a total debt to capitalization ratio. The Company was in compliance with these requirements throughout 2014.

The sale of the Notes was made by RGRT in reliance on a private placement exemption from registration under the Securities Act of 1933, as amended. The proceeds of $109.4 million, net of issuance costs, from the sale of the Notes was used by RGRT to repay amounts borrowed under the revolving credit facility and will enable future nuclear fuel financing requirements of RGRT to be met with a combination of the Notes and amounts borrowed from the RCF.


-4	Revolving Credit Facility

On January 14, 2014, the Company and RGRT entered into a second amended and restated credit agreement related to the RCF with JP Morgan Chase Bank, N.A., as administrative agent and issuing bank, and Union Bank, N.A., as syndication agent, and various lending banks party thereto. Under the terms of the agreement, the Company has available $300 million and the ability to increase the RCF by up to $100 million (up to a total of $400 million) upon the satisfaction of certain conditions, more fully set forth in the agreement, including obtaining commitments from lenders or third party financial institutions. The RCF has a term ending January 2019. The Company may extend the maturity date up to two times, in each case for an additional one year period upon the satisfaction of certain conditions.

The RCF provides that amounts borrowed by the Company may be used for, among other things, working capital and general corporate purposes. Any amounts borrowed by RGRT may be used, among other things, to finance the acquisition and processing of nuclear fuel. Amounts borrowed by RGRT are guaranteed by the Company and the balance borrowed under the RCF is recorded as short-term borrowings on the balance sheet. The RCF is unsecured. The RCF requires compliance with certain covenants, including a total debt to capitalization ratio. The Company was in compliance with these requirements throughout 2014. As of December 31, 2014, the total amount borrowed by RGRT was $14.5 million for nuclear fuel under the RCF. As of December 31, 2014, no borrowings were outstanding under this facility for working capital and general corporate purposes. The weighted average interest rate on the RCF was 1.3% as of December 31, 2014.







As of December 31, 2014, the scheduled maturities for the next five years of long-term debt are as follows (in thousands):




2015	$	15,000

2016	—

2017	83,300

2018	—

2019	—

The $14.5 million outstanding on the RCF for nuclear fuel financing purposes is anticipated to be paid in 2015.

Income_Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2014
Income Taxes [Abstract]
Income Tax Disclosure	Income Taxes
	The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and liabilities at December 31, 2014 and 2013 are presented below (in thousands):


		December 31,
		2014				2013
	Deferred tax assets:
	Benefit of tax loss carryforwards	$	—			$	17,709

	Alternative minimum tax credit carryforward	17,701				21,638

	Pensions and benefits	64,407				54,652

	Asset retirement obligation	25,725				23,727

	Other	15,768				14,485

	Total gross deferred tax assets	123,601				132,211

	Deferred tax liabilities:
	Plant, principally due to depreciation and basis differences	(536,264		)		(511,847		)
	Decommissioning	(40,373		)		(35,489		)
	Deferred fuel	(3,531		)		(2,171		)
	Other	(3,630		)		(5,664		)
	Total gross deferred tax liabilities	(583,798		)		(555,171		)
	Net accumulated deferred income taxes	$	(460,197	)		$	(422,960	)
	Based on the average annual book income before taxes for the prior three years, excluding the effects of unusual or infrequent items, the Company believes that the deferred tax assets will be fully realized at current levels of book and taxable income.
	The Company recognized income tax expense for 2014, 2013 and 2012 as follows (in thousands):


		Years Ended December 31,
		2014				2013				2012
	Income tax expense:
	Federal:
	Current	$	(1,250	)		$	(2,877	)		$	1,487

	Deferred	38,810				45,024				43,187

	Total federal income tax	37,560				42,147				44,674

	State:
	Current	3,209				1,854				1,931

	Deferred	641				(414		)		697

	Total state income tax	3,850				1,440				2,628

	Generation (amortization) of accumulated investment tax credits	(322		)		68				(323		)

	Total income tax expense	$	41,088			$	43,655			$	46,979

	As of December 31, 2014, the Company had $17.7 million of AMT credit carryforwards that have an unlimited life. As of December 31, 2014, the Company has utilized all of the federal and state tax loss carryfowards.
	Income tax provisions differ from amounts computed by applying the statutory federal income tax rate of 35% to book income before federal income tax as follows (in thousands):


		Years Ended December 31,
		2014				2013				2012
	Federal income tax expense computed on income at statutory rate	$	46,381			$	46,283			$	48,239

	Difference due to:
	State taxes, net of federal benefit	1,902				936				1,708

	AEFUDC	(3,757		)		(2,149		)		(1,845		)
	Permanent tax differences	(2,921		)		(1,153		)		(604		)
Other	(517		)		(262		)		(519		)
Total income tax expense	$	41,088			$	43,655			$	46,979

Effective income tax rate	31		%		33		%		34.1		%
The Company files income tax returns in the United States ("U.S.") federal jurisdiction and in the states of Texas, New Mexico and Arizona. The Company is no longer subject to tax examination by the taxing authorities in the federal and New Mexico jurisdictions for years prior to 2010. The Company is currently under audit in Texas for tax years 2007 through 2011 and in Arizona for tax years 2009 through 2012. The Company reached a settlement agreement with the Arizona Department of Revenue (“ADOR”) in March 2014 in their audit of income tax returns for the years 1998 through 2007 which did not have a material effect on income tax expense. Additionally, the Company reached a settlement with ADOR in September of 2014 in their audit of the income tax return for 2008 which did not have a material effect on income tax expense.
On December 19, 2014, the President signed the Tax Increase Prevention Act of 2014. This act included the extension of bonus depreciation which impacted the Company. The Company recorded the impact of the law change in December 2014, which resulted in an $0.8 million increase in income tax expense due to a decrease in the domestic production activities deduction which is limited by taxable income.
FASB guidance prescribes a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. In January 2010, the Company filed for a change of accounting method with the IRS related to the way in which units of property are determined for purposes of determining capitalized tax assets. The change was included in the 2009 federal income tax return, with additional amounts included in the 2010 to 2013 federal income tax returns. The Company recorded an unrecognized tax position of $1.6 million in 2012, related to the change in accounting method in 2009 through 2012. In 2013, a $4.5 million decrease was made to the reserve related to the change in accounting method. The decrease was primarily the result of the completion of IRS audits for tax years 2009 to 2012. In September 2014, the Company received an Issue Resolution Agreement (“IRA”) from IRS regarding the generation repairs deduction for all years. In the IRA, the IRS declared that the method used by the Company to calculate the generation repair deduction was substantially the same as the method outlined in the Revenue Procedure and declared that therefore no adjustment to the deduction taken in previous tax returns by the Company was required. As a result of the IRA, the Company recorded a $2.8 million decrease to eliminate the balance of the reserve related to the change in accounting method. The Company recorded an unrecognized tax position of $2.1 million, $0.5 million and $1.4 million in 2014, 2013 and 2012, respectively, related to depreciation and other amounts deducted in current and prior year Texas franchise tax returns. The Company recorded a decrease of $1.3 million (net of an increase of $0.4 million) to its unrecognized tax position in 2014 and an increase of $1.3 million (net of a decrease of $0.4 million) in 2013 related to tax credits taken in prior year Arizona income tax returns, which have been settled through audit. A reconciliation of the December 31, 2014, 2013 and 2012 amount of unrecognized tax benefits is as follows (in thousands):


	2014				2013				2012
Balance at January 1	$	7,200			$	9,800			$	9,500

Additions for tax positions related to the current year	300				600				1,600

Reductions for tax positions related to the current year	—				—				(900		)

Additions for tax positions of prior years	2,200				1,700				1,400

Reductions for tax positions of prior years	(4,500		)		(4,900		)		(1,800		)
Balance at December 31	$	5,200			$	7,200			$	9,800

If recognized, $3.0 million of the unrecognized tax position at December 31, 2014, would affect the effective tax rate. The Company recognized income tax expense for an unrecognized tax position of $0.5 million for the year ended December 31, 2014.
The Company recognizes in tax expense interest and penalties related to tax benefits that have not been recognized. During the year ended December 31, 2012, the Company recognized a benefit of $0.3 million in interest. For the years ended December 31, 2014 and 2013, the Company recognized interest expense of $0.1 million and $0.2 million, respectively. The Company had approximately $0.5 million and $0.4 million accrued for the payment of interest and penalties at December 31, 2014 and 2013, respectively.

Commitments_Contingencies_and_

Commitments, Contingencies and Uncertainties	12 Months Ended
Commitments, Contingencies and Uncertainties	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Commitments, Contingencies And Uncertainties	Commitments, Contingencies and Uncertainties
	Power Purchase and Sale Contracts
	To supplement its own generation and operating reserves and to meet required renewable portfolio standards, the Company engages in power purchase arrangements which may vary in duration and amount based on evaluation of the Company’s resource needs, the economics of the transactions, and specific renewable portfolio requirements. The Company has entered into the following significant agreements with various counterparties for forward purchases and sales of electricity:


							Commercial
							Operation
	Type of Contract		Counterparty	Quantity		Term	Date
	Power Purchase and Sale Agreement		Freeport	25	MW	December 2008 through December 2015	N/A
	Power Purchase and Sale Agreement		Freeport	100	MW	June 2006 through December 2021	N/A
	Power Purchase Agreement		Hatch Solar Energy Center I, LLC	5	MW	July 2011 through June 2036	Jul-11
	Power Purchase Agreement		NRG	20	MW	August 2011 through August 2031	Aug-11
	Power Purchase Agreement		Sun Edison 1	10	MW	June 2012 through June 2037	Jun-12
	Power Purchase Agreement		Sun Edison 2	12	MW	May 2012 through May 2037	May 2012
	Power Purchase Agreement		Macho Springs Solar, LLC	50	MW	May 2014 through April 2034	May-14
	Power Purchase Agreement		PSEG El Paso Solar Energy Center	10	MW	December 2014 through November 2044	Dec-14
	The Company has a firm Power Purchase and Sale Agreement with Freeport-McMoran Copper and Gold Energy Services LLC ("Freeport") which provides for Freeport to deliver energy to the Company from its ownership interest in the Luna Energy Facility (a natural gas-fired combined cycle generation facility located in Luna County, New Mexico) and for the Company to deliver a like amount of energy at Greenlee, Arizona. The Company may purchase the quantities noted in the table above at a specified price at times when energy is not exchanged under the Power Purchase and Sale Agreement. Upon mutual agreement, the contract allows the parties to increase the amount of energy that is purchased and sold under the Power Purchase and Sale Agreement. The parties have agreed to increase the amount up to 125 MW through December 2015. The contract was approved by the FERC and continues through December 31, 2021. On December 30, 2014, the FERC issued an order authorizing the disposition, i.e. sale, of Freeport's interest in the Luna facility to Samchully Power & Utilities 1, LLC. Freeport will retain the ability to purchase up to the full amount of its previous ownership share of the Luna facility of approximately 190 MW, thereby continuing to fulfill its obligations pursuant to the Power Purchase and Sale Agreement.
	The Company has a 25-year purchase power agreement with Hatch Solar Energy Center I, LLC to purchase all of the output from a solar photovoltaic plant located in southern New Mexico which began commercial operation in July 2011. The Company entered into a 20-year contract with NRG Solar Roadrunner LLC ("NRG") to purchase all of the output of a solar photovoltaic plant built in southern New Mexico which began commercial operation in August 2011. The Company has 25-year purchase power agreements to purchase all of the output of two additional solar photovoltaic plants located in southern New Mexico, SunEdison 1 and SunEdison 2 which began commercial operation on June 25, 2012 and May 2, 2012, respectively. The Company entered into these contracts to help meet its renewable portfolio requirements. The Company has a 20-year purchase power agreement with Macho Springs Solar, LLC to purchase the entire generation output delivered from the 50 MW Macho Springs solar photovoltaic plant located in Luna County, New Mexico which began commercial operation on May 23, 2014. The Company has a 30-year purchase power agreement with PSEG El Paso Solar Energy Center ("PSEG") to purchase the total output of approximately 10 MW from a solar photovoltaic plant that PSEG owns and operates on land subleased from the Company in proximity to its Newman Power Station. This solar photovoltaic plant began commercial operation on December 30, 2014.
	The Company entered into an agreement in 2009 to purchase capacity and unit contingent energy during 2010 from Shell Energy North America ("Shell"). Under the agreement, the Company provided natural gas to Pyramid Unit No. 4 where Shell had the right to convert natural gas to electric energy. The Company entered into a contract with Shell on May 17, 2010 to extend the term of the capacity and unit contingent energy purchase from January 1, 2011 through September 30, 2014.
	Environmental Matters
	General. The Company is subject to extensive laws, regulations and permit requirements with respect to air and greenhouse gas emissions, water discharges, soil and water quality, waste management and disposal, natural resources and other environmental matters by federal, state, regional, tribal and local authorities. Failure to comply with such laws, regulations and requirements can result in actions by authorities or other third parties that might seek to impose on the Company administrative, civil and/or criminal penalties or other sanctions. In addition, releases of pollutants or contaminants into the environment can result in costly cleanup liabilities. These laws, regulations and requirements are subject to change through modification or reinterpretation, or the introduction of new laws and regulations and, as a result, the Company may face additional capital and operating costs to comply. Certain key environmental issues, laws and regulations facing the Company are described further below.
	Air Emissions. The U.S. Clean Air Act ("CAA"), associated regulations and comparable state and local laws and regulations relating to air emissions impose, among other obligations, limitations on pollutants generated during the operations of the Company's facilities and assets, including sulfur dioxide ("SO2"), particulate matter ("PM"), nitrogen oxides ("NOx") and mercury.
	Clean Air Interstate Rule/Cross State Air Pollution Rule. The EPA promulgated the Cross-State Air Pollution Rule ("CSAPR") in August 2011, which rule involves requirements to limit emissions of NOx and SO2 from certain of the Company's power plants in Texas and/or purchase allowances representing other parties' emissions reductions. CSAPR was intended to replace the EPA's 2005 Clean Air Interstate Rule ("CAIR"). While the U.S. Court of Appeals for the District of Columbia Circuit ("D.C. Circuit") vacated CSAPR in August 2012 and allowed CAIR to stand until the EPA issued a proper replacement, on April 29, 2014, the U.S. Supreme Court reversed and upheld CSAPR, remanding certain portions of CSAPR to the D.C. Circuit for further consideration. On June 26, 2014, the EPA filed a motion asking the D.C. Circuit to lift its stay on CSAPR. On October 23, 2014, the D.C. Circuit lifted its stay of CSAPR, and while we are unable to determine the full impact of the reinstatement of CSAPR until the D.C. Circuit and the EPA take further action, the Company believes it is currently positioned to comply with CSAPR.
	National Ambient Air Quality Standards. Under the CAA, the EPA sets National Ambient Air Quality Standards ("NAAQS") for six criteria pollutants considered harmful to public health and the environment, including PM, NOx, carbon monoxide ("CO"), ozone and SO2. NAAQS must be reviewed by the EPA at five-year intervals. In 2010, the EPA tightened the NAAQS for both NOx and SO2. The EPA is considering a 1-hour secondary NAAQS for NOx and SO2. In January 2013, the EPA tightened the NAAQS for fine PM. On November 26, 2014, the EPA announced a proposal to tighten the 2008 primary and secondary ground-level ozone NAAQS. Ozone is the main component of smog. While not directly emitted into the air, it forms from precursors, including NOx and volatile organic compounds, in combination with sunlight. EPA proposes to tighten the current 8-hour primary (health-based) standard of 75 parts per billion ("ppb") to a level within its preferred range of 65 to 70 ppb, while also taking comment on a potential standard as low as 60 ppb and on retaining the current standard. The EPA intends to issue a final rule by October 2015.The Company continues to evaluate what impact these final and proposed NAAQS could have on its operations. If the Company is required to install additional equipment to control emissions at its facilities, the revised NAAQS could have a material impact on its operations and financial results.
	Utility MACT. The operation of coal-fired power plants, such as Four Corners, results in emissions of mercury and other air toxics. In December 2011, the EPA finalized Mercury and Air Toxics Standards (known as the "Utility MACT") for oil-and coal-fired power plants, which requires significant reductions in emissions of mercury and other air toxics. Several judicial and other challenges have been made to this rule, with a U.S. Supreme Court decision expected this year. These challenges notwithstanding, companies impacted by the new standards will generally have up to three years to comply. Information from the Four Corners plant operator, APS, indicates that APS currently believes Units 4 and 5 will require no additional modifications to achieve compliance with the Utility MACT standards.
	Other Laws and Regulations and Risks. As stated above, the Company has entered into an agreement to sell its interest in Four Corners to APS at the expiration of the 50-year participation agreement in July 2016. The Company believes that it has better economic and cleaner alternatives for serving the energy needs of its customers than coal-fired generation, which is subject to extensive regulation and litigation. By ceasing its participation in Four Corners, the Company will avoid the significant cost required to install expensive pollution control equipment in order to continue operation of the plant as well as the risks of water availability that might adversely affect the amount of power available, or the price thereof, from Four Corners in the future. The closing of the transaction is subject to the receipt of regulatory approvals.
	Climate Change. The U.S. federal government has either considered, proposed and/or finalized legislation or regulations limiting GHG emissions, including carbon dioxide. In particular, the U.S. Congress has considered legislation to restrict or regulate GHG emissions. In the past few years, the EPA began using the CAA to regulate carbon dioxide and other GHG emissions, such as the 2009 GHG Reporting Rule and the EPA’s sulfur hexafluoride ("SF6") reporting rule, both of which apply to the Company, as well as the EPA’s 2010 actions to impose permitting requirements on new and modified sources of GHG emissions. After announcing his plan to address climate change in 2013, the President directed the EPA to issue proposals for GHG rulemaking addressing power plants. In January 2014, the EPA published a proposal to establish new source performance standards limiting carbon dioxide emissions from new electric generating units, and in June 2014, a proposal to create carbon dioxide standards for existing and modified/reconstructed power plants. The Company participated in the associated proposed rulemaking comment periods. On January 7, 2015, EPA announced it plans to issue final rules for new, existing and modified/reconstructed power plants by this summer. Given the very significant remaining uncertainties regarding these EPA rules, the Company believes it is impossible to meaningfully quantify the costs of these potential requirements at present.
	In addition, almost half the U.S. states, either individually and/or through multi-state regional initiatives, have begun to consider how to address GHG emissions and have developed, or are actively considering the development of emission inventories or regional GHG cap and trade programs. While a significant portion of the Company's generation assets are nuclear or gas-fired, and as a result, the Company believes that its greenhouse gas emissions are low relative to electric power companies who rely more on coal-fired generation, current and future legislation and regulation of GHGs or any future related litigation could impose significant costs and/or operating restrictions on the Company, reduced demand for the power the Company generates and/or require the Company to purchase rights to emit GHGs, any of which could be material to the Company's business, financial condition, reputation or results of operations.
	Climate change also has potential physical effects that could be relevant to the Company's business. In particular, some studies suggest that climate change could affect the Company's service area by causing higher temperatures, less winter precipitation and less spring runoff, as well as by causing more extreme weather events. Such developments could change the demand for power in the region and could also impact the price or ready availability of water supplies or affect maintenance needs and the reliability of Company equipment. The Company believes that material effects on the Company's business or results of operations may result from the physical consequences of climate change, the regulatory approach to climate change ultimately selected and implemented by governmental authorities, or both. Given the very significant remaining uncertainties regarding whether and how these issues will be regulated, as well as the timing and severity of any physical effects of climate change, the Company believes it is impossible to meaningfully quantify the costs of these potential impacts at present.
	Environmental Litigation and Investigations. Since 2009, the EPA and certain environmental organizations have been scrutinizing, and in some cases, have filed lawsuits, relating to certain air emissions and air permitting matters related to Four Corners. In particular, since July 2011, the U.S. Department of Justice (the "DOJ"), on behalf of the EPA, and APS have been engaged in substantive settlement negotiations in an effort to resolve certain of the pending matters. The allegations being addressed through settlement negotiations are that APS failed to obtain the necessary permits and install the controls necessary under the CAA to reduce SO2, NOx, and PM, and that defendants failed to obtain an operating permit under Title V of the CAA that reflects applicable requirements imposed by law. In November 2014, the DOJ provided APS with a draft consent decree to settle the EPA matter, which decree contains specific provisions for the reduction and control of NOx, SO2, and PM, as well as provisions for a civil penalty, and expenditures on environmental mitigation projects with an emphasis on projects that address alleged harm to the Navajo Nation. Settlement discussions are on-going and the Company is unable to predict with certainty the final outcome of these settlement negotiations. The Company has accrued a total of $0.6 million as its estimated share of the loss contingency related to this matter.
	Earthjustice filed a lawsuit in the United States District Court for New Mexico on October 4, 2011 for alleged violations of the Prevention of Significant Deterioration ("PSD") provisions of the CAA related to Four Corners. On January 6, 2012, Earthjustice filed a First Amended Complaint adding claims for violations of the CAA's New Source Performance Standards ("NSPS") program. Among other things, the plaintiffs seek to have the court enjoin operations at Four Corners until APS applies for and obtains any required PSD permits and complies with the referenced NSPS program. The plaintiffs further request the court to order the payment of civil penalties, including a beneficial mitigation project. On April 2, 2012, APS and the other Four Corners participants filed motions to dismiss with the court. The case is being held in abeyance while the parties seek to negotiate a settlement. On March 30, 2013, upon joint motion of the parties, the court issued an order deeming the motions to dismiss withdrawn without prejudice during pendency of the stay. At such time as the stay is lifted, APS, the Company and the other Four Corners participants may reinstate the motions to dismiss. Settlement discussions are ongoing. The Company is unable to predict the outcome of this litigation.
	New Mexico Tax Matter Related to Coal Supplied to Four Corners
	On May 23, 2013, the New Mexico Taxation and Revenue Department issued a notice of assessment for coal severance surtax, penalty, and interest totaling approximately $30 million related to coal supplied under the coal supply agreement for Four Corners (the "Assessment"). The Company's share of the assessment is approximately $1.5 million. On behalf of the Four Corners participants, the coal supplier made a partial payment of the Assessment and immediately filed a refund claim with respect to that partial payment in August 2013. The New Mexico Taxation and Revenue Department denied the refund claim. On December 19, 2013, the coal supplier and APS, on its own behalf and as operating agent for Four Corners, filed complaints with the New Mexico District Court contesting both the validity of the Assessment and the refund claim denial. APS believes the Assessment and the refund claim denial are without merit. The Company cannot predict the timing, results, or potential impacts of the outcome of this litigation.
	Lease Agreements
	The Company leases land in El Paso adjacent to the Newman Power Station under a lease which expires in June 2033 with a renewal option of 25 years. In addition, the Company leases certain warehouse facilities in El Paso under a lease which expires in December 2015. The Company also has several other leases for office, parking facilities and equipment which expire within the next three years . The Company has transmission and distribution lines which are operated under various property easement agreements. The majority of these easements include renewal options which the Company routinely exercises. These lease agreements do not impose any restrictions relating to issuance of additional debt, payment of dividends or entering into other lease arrangements. The Company has no significant capital lease agreements.
	The Company's total annual rental expense related to operating leases was $1.8 million, $1.2 million, and $1.3 million for 2014, 2013 and 2012, respectively. As of December 31, 2014, the Company’s minimum future rental payments for the next five years are as follows (in thousands):




	2015	$	1,386
	2015	$	1,386
	2016	838
	2016	838
	2017	623
	2017	623
	2018	512
	2018	512
	2019	516
	2019	516

Litigation

Litigation	12 Months Ended
Litigation	Dec. 31, 2014
Litigation [Abstract]
Legal Matters Disclosure	Litigation
	The Company is a party to various legal actions. In many of these matters, the Company has excess casualty liability insurance that covers the various claims, actions and complaints. Based upon a review of these claims and applicable insurance coverage, the Company believes that none of these claims will have a material adverse effect on the financial position, results of operations or cash flows of the Company. The Company expenses legal costs, including expenses related to loss contingencies, as they are incurred.
	See Note C and Note K for discussion of the effects of government legislation and regulation on the Company as well as certain pending legal proceedings.

Employee_Benefits

Employee Benefits	12 Months Ended
Employee Benefits	Dec. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Pension and Other Postretirement Benefits Disclosure	Employee Benefits

	Retirement Plans
	The Company’s Retirement Income Plan (the "Retirement Plan") is a qualified noncontributory defined benefit plan. Upon retirement or death of a vested plan participant, assets of the Retirement Plan are used to pay benefit obligations under the Retirement Plan. Contributions from the Company are at least the minimum funding amounts required by the IRS, as actuarially calculated. The assets of the Retirement Plan are primarily invested in common collective trusts which hold equity securities, debt securities and cash equivalents and are managed by a professional investment manager appointed by the Company.
	The Company has two non-qualified retirement plans that are non-funded defined benefit plans. The Company's Supplemental Retirement Plan covers certain former employees and directors of the Company. The Excess Benefit Plan, was adopted in 2004 and covers certain active and former employees of the Company. The benefit cost for the non-qualified retirement plans are based on substantially the same actuarial methods and economic assumptions as those used for the Retirement Plan.
	During the quarter ended March 31, 2014, the Company implemented certain amendments to the Retirement Plan and Excess Benefit Plan. In the first quarter of 2014, the Company offered a cash balance pension plan as an alternative to its current final average pay pension plan for employees hired prior to January 1, 2014. The cash balance pension plan also included an enhanced employer matching contribution to the employee’s respective 401(k) Defined Contribution Plan (discussed below). For employees that elected the new cash balance feature of the plans, the pension benefit earned under the existing final average pay feature of the plans was frozen as of March 31, 2014. Employees hired after January 1, 2014 are automatically enrolled in the cash balance pension plan. The amendments to the plans were effective April 1, 2014. As a result of these actions, the Company remeasured the assets and liabilities of the plans, based on actuarially determined estimates, using the close of the alternative choice election period of February 28, 2014, as the remeasurement date.
	Prior to December 31, 2013, employees who completed one year of service with the Company and worked at least a minimum number of hours each year were covered by the final average pay formula of the plan. For participants that continue to be covered by the final average pay formula, retirement benefits are based on the employee’s final average pay and years of service. The cash balance pension plan covers employees beginning on their employment commencement date or re-employment commencement date in any plan year in which the employee completes at least a minimum number of hours of service. Retirement benefits under the cash balance pension plan are based on the employee’s cash balance account, consisting of pay credits and interest credits.
	The Company complies with FASB guidance on disclosure for pension and other post-retirement plans that requires disclosure of investment policies and strategies, categories of investment and fair value measurements of plan assets, and significant concentrations of risk.



	The obligations and funded status of the plans are presented below (in thousands):


		December 31,
		2014								2013
		Retirement				Non-Qualified				Retirement				Non-Qualified
		Income				Retirement				Income				Retirement
		Plan				Plans				Plan				Plans
	Change in projected benefit obligation:
	Benefit obligation at end of prior year	$	317,815			$	25,898			$	320,846			$	27,241
	Benefit obligation at end of prior year	$	317,815			$	25,898			$	320,846			$	27,241
	Service cost	8,284				303				9,137				190
	Service cost	8,284				303				9,137				190
	Interest cost	14,001				1,041				12,742				872
	Interest cost	14,001				1,041				12,742				872
	Amendments (a)	(33,700		)		(500		)		—				—
	Amendments (a)	(33,700		)		(500		)		—				—
	Actuarial (gain) loss	50,741				3,508				(15,373		)		(533		)
	Actuarial (gain) loss	50,741				3,508				(15,373		)		(533		)
	Benefits paid	(16,008		)		(1,853		)		(9,537		)		(1,872		)
	Benefit obligation at end of year	341,133				28,397				317,815				25,898
	Benefit obligation at end of year	341,133				28,397				317,815				25,898
	Change in plan assets:
	Fair value of plan assets at end of prior year	257,831				—				220,568				—
	Fair value of plan assets at end of prior year	257,831				—				220,568				—
	Actual return on plan assets	22,116				—				31,800				—
	Actual return on plan assets	22,116				—				31,800				—
	Employer contribution	9,000				1,853				15,000				1,872
	Employer contribution	9,000				1,853				15,000				1,872
	Benefits paid	(16,008		)		(1,853		)		(9,537		)		(1,872		)
	Fair value of plan assets at end of year	272,939				—				257,831				—
	Fair value of plan assets at end of year	272,939				—				257,831				—
	Funded status at end of year	$	(68,194	)		$	(28,397	)		$	(59,984	)		$	(25,898	)
	_____________________
	(a)Amendments relate to the modification of the Company’s Retirement Plan and Excess Benefit Plan discussed above.

	Amounts recognized in the Company's balance sheets consist of the following (in thousands):


		December 31,
		2014								2013
		Retirement				Non-Qualified				Retirement				Non-Qualified
		Income				Retirement				Income				Retirement
		Plan				Plans				Plan				Plans
	Current liabilities	$	—			$	(2,319	)		$	—			$	(1,870	)
	Current liabilities	$	—			$	(2,319	)		$	—			$	(1,870	)
	Noncurrent liabilities	(68,194		)		(26,078		)		(59,984		)		(24,028		)
	Total	$	(68,194	)		$	(28,397	)		$	(59,984	)		$	(25,898	)
	The accumulated benefit obligation in excess of plan assets is as follows (in thousands):


		December 31,
		2014								2013
	Retirement				Non-Qualified				Retirement				Non-Qualified
	Income				Retirement				Income				Retirement
	Plan				Plans				Plan				Plans
Projected benefit obligation	$	(341,133	)		$	(28,397	)		$	(317,815	)		$	(25,898	)
Accumulated benefit obligation	(312,762		)		(27,603		)		(275,555		)		(25,077		)
Fair value of plan assets	272,939				—				257,831				—
Fair value of plan assets	272,939				—				257,831				—

Amounts recognized in accumulated other comprehensive income consist of the following (in thousands):


	Years Ended December 31,
	2014								2013
	Retirement				Non-Qualified				Retirement				Non-Qualified
	Income				Retirement				Income				Retirement
	Plan				Plans				Plan				Plans
Net loss	$	124,407			$	11,341			$	85,261			$	8,508
Net loss	$	124,407			$	11,341			$	85,261			$	8,508
Prior service cost (benefit)	(30,811		)		(264		)		—				219
Prior service cost (benefit)	(30,811		)		(264		)		—				219
Total	$	93,596			$	11,077			$	85,261			$	8,727
Total	$	93,596			$	11,077			$	85,261			$	8,727
The following are the weighted-average actuarial assumptions used to determine the benefit obligations:


	December 31,
	2014									2013
				Non-Qualified									Non-Qualified
	Retirement			Supplemental			Excess			Retirement			Supplemental			Excess
	Income			Retirement			Benefit			Income			Retirement			Benefit
	Plan			Plan			Plan			Plan			Plan			Plan
Discount rate	4	%		3.4	%		4.1	%		4.9	%		3.9	%		4.9	%
Rate of compensation increase	4.5	%		N/A			4.5	%		4.75	%		N/A			4.75	%
Rate of compensation increase	4.5	%		N/A			4.5	%		4.75	%		N/A			4.75	%
The Company reassesses various actuarial assumptions at least on an annual basis. The discount rate is reviewed at each measurement date. The discount rate used to measure obligations is based on a spot rate yield curve that matches projected future payments with the appropriate interest rate applicable to the timing of the projected future benefit payments. A 1% increase in the discount rate would decrease the December 31, 2014 retirement plans' projected benefit obligation by 11.7%. A 1% decrease in the discount rate would increase the December 31, 2014 retirement plans' projected benefit obligation by 14.6%.
The components of net periodic benefit cost are presented below (in thousands):


	Years Ended December 31,
	2014								2013								2012
	Retirement				Non-Qualified				Retirement				Non-Qualified				Retirement				Non-Qualified
	Income				Retirement				Income				Retirement				Income				Retirement
	Plan				Plans				Plan				Plans				Plan				Plans
Service cost	$	8,284			$	303			$	9,137			$	190			$	8,530			$	299
Service cost	$	8,284			$	303			$	9,137			$	190			$	8,530			$	299
Interest cost	14,001				1,041				12,742				872				12,594				963
Interest cost	14,001				1,041				12,742				872				12,594				963
Expected return on plan assets	(18,699		)		—				(17,108		)		—				(14,443		)		—
Expected return on plan assets	(18,699		)		—				(17,108		)		—				(14,443		)		—
Amortization of:
Net loss	8,178				675				10,437				661				10,729				627
Net loss	8,178				675				10,437				661				10,729				627
Prior service cost (benefit)	(2,889		)		(17		)		3				94				21				94
Prior service cost (benefit)	(2,889		)		(17		)		3				94				21				94
Net periodic benefit cost	$	8,875			$	2,002			$	15,211			$	1,817			$	17,431			$	1,983
Net periodic benefit cost	$	8,875			$	2,002			$	15,211			$	1,817			$	17,431			$	1,983













The changes in benefit obligations recognized in other comprehensive income are presented below (in thousands):


	Years Ended December 31,
	2014								2013								2012
	Retirement				Non-Qualified				Retirement				Non-Qualified				Retirement				Non-Qualified
	Income				Retirement				Income				Retirement				Income				Retirement
	Plan				Plans				Plan				Plans				Plan				Plans
Net (gain) loss	$	47,324			$	3,508			$	(30,065	)		$	(533	)		$	6,672			$	1,337
Net (gain) loss	$	47,324			$	3,508			$	(30,065	)		$	(533	)		$	6,672			$	1,337
Prior service benefit	(33,700		)		(500		)		—				—				—				—
Prior service benefit	(33,700		)		(500		)		—				—				—				—
Amortization of:
Net loss	(8,178		)		(675		)		(10,437		)		(661		)		(10,729		)		(627		)
Prior service (cost) benefit	2,889				17				(3		)		(94		)		(21		)		(94		)
Prior service (cost) benefit	2,889				17				(3		)		(94		)		(21		)		(94		)
Total recognized in other comprehensive income	$	8,335			$	2,350			$	(40,505	)		$	(1,288	)		$	(4,078	)		$	616
Total recognized in other comprehensive income	$	8,335			$	2,350			$	(40,505	)		$	(1,288	)		$	(4,078	)		$	616
The total amount recognized in net periodic benefit costs and other comprehensive income are presented below (in thousands):


	Years Ended December 31,
	2014								2013								2012
	Retirement				Non-Qualified				Retirement				Non-Qualified				Retirement				Non-Qualified
	Income				Retirement				Income				Retirement				Income				Retirement
	Plan				Plans				Plan				Plans				Plan				Plans
Total recognized in net periodic benefit cost and other comprehensive income	$	17,210			$	4,352			$	(25,294	)		$	529			$	13,353			$	2,599
	$	17,210			$	4,352			$	(25,294	)		$	529			$	13,353			$	2,599
The following are amounts in accumulated other comprehensive income that are expected to be recognized as components of net periodic benefit cost during 2015 (in thousands):


	Retirement				Non-Qualified
	Income				Retirement
	Plan				Plans
Net loss	$	10,220			$	850
Net loss	$	10,220			$	850
Prior service benefit	(3,470		)		(40		)
The following are the weighted-average actuarial assumptions used to determine the net periodic benefit cost for the twelve months ended December 31:


	2014 (a)									2013									2012
				Non-Qualified									Non-Qualified									Non-Qualified
	Retirement			Supplemental Retirement			Excess			Retirement			Supplemental Retirement			Excess			Retirement			Supplemental Retirement		Excess
	Income			Plan			Benefit			Income			Plan			Benefit			Income			Plan		Benefit
	Plan						Plan			Plan						Plan			Plan					Plan
Discount rate	4.9	%		3.9	%		4.9	%		4	%		3.1	%		4	%		4.3	%		3.6	%	4.1	%
Expected long-term return on plan assets	7.5	%		N/A			N/A			7.5	%		N/A			N/A			7.5	%		N/A		N/A
Expected long-term return on plan assets	7.5	%		N/A			N/A			7.5	%		N/A			N/A			7.5	%		N/A		N/A
Rate of compensation increase	4.75	%		N/A			4.75	%		4.75	%		N/A			4.75	%		5	%		N/A		5	%
Rate of compensation increase	4.75	%		N/A			4.75	%		4.75	%		N/A			4.75	%		5	%		N/A		5	%
_____________________

(a)	The Retirement Plan and the Excess Benefit Plan were remeasured on February 28, 2014 due to the above mentioned plan amendment. The discount rate used to remeasure the benefit obligation was 4.6% for the Retirement Plan and 4.5% for the Excess Benefit Plan, compared to 4.9% for both plans as of January 1, 2014. All other assumptions remained consistent with assumptions used at January 1, 2014.

The Company’s overall expected long-term rate of return on assets is 7.5% effective January 1, 2014, which is both a pre-tax and after-tax rate as pension funds are generally not subject to income tax. The expected long-term rate of return is based on the weighted average of the expected returns on investments based upon the target asset allocation of the pension fund. The Company’s target allocations for the plan’s assets are presented below:


		December 31, 2014
Equity securities		55	%
Fixed income		40	%
Alternative investments		5	%
Total		100	%
The Retirement Plan invests the majority of its plan assets in common collective trusts which includes a diversified portfolio of domestic and international equity securities and fixed income securities. The Retirement Plan fund also invests in a real estate limited partnership. The expected rate of returns for the funds are assessed annually and are based on long-term relationships among major asset classes and the level of incremental returns that can be earned by the successful implementation of different active investment management strategies. Equity returns are based on estimates of long-term inflation rate, real rate of return, 10-year Treasury bond premium over cash and equity risk premium. Fixed income returns are based on maturity, long-term inflation, real rate of return and credit spreads.
FASB guidance on disclosure for pension plans requires disclosure of fair value measurements of plan assets. To increase consistency and comparability in fair value measurements, FASB guidance on fair value measurements established a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three levels as follows:


•	Level 1 – Observable inputs that reflect quoted market prices for identical assets and liabilities in active markets. Prices or securities held in the mutual funds and underlying portfolios of the Retirement Plan are primarily obtained from independent pricing services. These prices are based on observable market data.


•	Level 2 – Inputs other than quoted market prices included in Level 1 that are observable for the asset or liability either directly or indirectly. The fair value of the Guaranteed Investment Contract was based on market interest rates of investments with similar terms and risk characteristics. The Common Collective Trusts are valued using the net asset value ("NAV") provided by the administrator of the fund. The NAV price is quoted on a restrictive market although the underlying investments are traded on active markets.


•	Level 3 – Unobservable inputs using data that is not corroborated by market data. The fair value of the real estate limited partnership is reported at the NAV of the investment.
The fair value of the Company’s Retirement Plan assets at December 31, 2014 and 2013, and the level within the three levels of the fair value hierarchy defined by FASB guidance on fair value measurements are presented in the table below (in thousands):


Description of Securities	Fair Value as of				Quoted Prices				Significant				Significant
	December 31,				in Active				Other				Unobservable
	2014				Markets for				Observable				Inputs
					Identical Assets				Inputs				(Level 3)
					(Level 1)				(Level 2)
Cash and Cash Equivalents	$	1,237			$	1,237			$	—			$	—
Cash and Cash Equivalents	$	1,237			$	1,237			$	—			$	—
Common Collective Trusts (a)
Equity funds	149,839				—				149,839				—
Equity funds	149,839				—				149,839				—
Fixed income funds	113,115				—				113,115				—
Fixed income funds	113,115				—				113,115				—
Total Common Collective Trusts	262,954				—				262,954				—
Total Common Collective Trusts	262,954				—				262,954				—
Limited Partnership Interest in Real Estate (b)	8,748				—				—				8,748
Limited Partnership Interest in Real Estate (b)	8,748				—				—				8,748
Total Plan Investments	$	272,939			$	1,237			$	262,954			$	8,748
Total Plan Investments	$	272,939			$	1,237			$	262,954			$	8,748



Description of Securities	Fair Value as of				Quoted Prices				Significant				Significant
	December 31,				in Active				Other				Unobservable
	2013				Markets for				Observable				Inputs
					Identical Assets				Inputs				(Level 3)
					(Level 1)				(Level 2)
Cash and Cash Equivalents	$	940			$	940			$	—			$	—
Cash and Cash Equivalents	$	940			$	940			$	—			$	—
Guaranteed Investment Contract	1,126				—				1,126				—
Guaranteed Investment Contract	1,126				—				1,126				—
Common Collective Trust (a)
Equity funds	142,960				—				142,960				—
Equity funds	142,960				—				142,960				—
Fixed income funds	103,948				—				103,948				—
Fixed income funds	103,948				—				103,948				—
Total Common Collective Trusts	246,908				—				246,908				—
Total Common Collective Trusts	246,908				—				246,908				—
Limited Partnership Interest in Real Estate (b)	8,857				—				—				8,857
Limited Partnership Interest in Real Estate (b)	8,857				—				—				8,857
Total Plan Investments	$	257,831			$	940			$	248,034			$	8,857
Total Plan Investments	$	257,831			$	940			$	248,034			$	8,857
_____________________

(a)	The Common Collective Trusts are invested in equity or fixed income securities, or a combination thereof. The investment objective of each trust is to produce returns in excess of, or commensurate with, its predefined index.

(b)	This investment is a commercial real estate partnership that purchases land, develops limited infrastructure, and sells it for commercial development. The Company is restricted from selling its partnership interest during the life of the partnership which is generally 5-7 years. Return on investment is realized as land is sold. The fair value of the limited partnership interest in real estate is based on the NAV of the partnership which reflects the appraised value of the land.
The table below reflects the changes in the fair value of investments in real estate during the period (in thousands):



	Fair Value of
	Investments in
	Real Estate
Balances at December 31, 2012	$	8,559
Balances at December 31, 2012	$	8,559
Unrealized gain in fair value	298
Unrealized gain in fair value	298
Balances at December 31, 2013	8,857
Balances at December 31, 2013	8,857
Sale of land	(357		)
Unrealized gain in fair value	248
Unrealized gain in fair value	248
Balances at December 31, 2014	$	8,748
Balances at December 31, 2014	$	8,748
There were no transfers in or out of Level 1 and Level 2 fair value measurements categories due to changes in observable inputs during the twelve month periods ending December 31, 2014 and 2013. Except as noted in the above table, there were no purchases, issuances, and settlements related to the assets in the Level 3 fair value measurement category during the twelve month periods ending December 31, 2014 and 2013.

The Company adheres to the traditional capital market pricing theory which maintains that over the long term, the risk of owning equities should be rewarded with a greater return than available from fixed income investments. The Company seeks to minimize the risk of owning equity securities by investing in funds that pursue risk minimization strategies and by diversifying its investments to limit its risks during falling markets. The investment manager has full discretionary authority to direct the investment of plan assets held in trust within the guidelines prescribed by the Company through the plan’s investment policy statement including the ability to hold cash equivalents. The investment guidelines of the investment policy statement are in accordance with the Employee Retirement Income Security Act of 1974 ("ERISA") and Department of Labor ("DOL") regulations.
The Company contributes at least the minimum funding amounts required by the IRS for the Retirement Plan, as actuarially calculated. The Company expects to contribute $11.3 million to its retirement plans in 2015.
The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid (in thousands):



	Retirement				Non-Qualified
	Income				Retirement
	Plan				Plans
2015	$	15,776			$	2,319
2015	$	15,776			$	2,319
2016	17,153				2,248
2016	17,153				2,248
2017	17,778				2,171
2017	17,778				2,171
2018	20,019				2,196
2018	20,019				2,196
2019	19,500				2,135
2019	19,500				2,135
2020-2024	103,703				10,720
2020-2024	103,703				10,720

401(k) Defined Contribution Plans
The Company sponsors 401(k) defined contribution plans covering substantially all employees. Annual matching contributions made to the savings plans for the years 2014, 2013 and 2012 were $3.0 million, $1.9 million, and $1.8 million, respectively. Historically, the Company had provided a 50 percent matching contribution up to 6 percent of the employee’s compensation subject to certain other limits and exclusions. Effective April 1, 2014, for employees who enrolled in the cash balance pension plan (discussed above), the Company provided a 100 percent matching contribution up to 6 percent of the employee's compensation subject to certain other limits and exclusions.
Other Post-retirement Benefits
The Company provides certain health care benefits for retired employees and their eligible dependents and life insurance benefits for retired employees only. Substantially all of the Company’s employees may become eligible for those benefits if they retire while working for the Company. Contributions from the Company are generally no more than the IRS tax deductible limit, as actuarially calculated. The assets of the plan are primarily invested in common collective trusts which hold equity securities, debt securities, and cash equivalents and are managed by a professional investment manager appointed by the Company.
The following table contains a reconciliation of the change in the benefit obligation, the fair value of plan assets, and the funded status of the plan (in thousands):


	December 31,
	2014				2013
Change in benefit obligation:
Benefit obligation at end of prior year	$	92,847			$	135,680
Benefit obligation at end of prior year	$	92,847			$	135,680
Service cost	2,845				3,843
Service cost	2,845				3,843
Interest cost	4,463				5,156
Interest cost	4,463				5,156
Actuarial loss (gain)	3,465				(48,778		)
Actuarial loss (gain)	3,465				(48,778		)
Amendment (a)	—				(97		)
Amendment (a)	—				(97		)
Benefits paid	(4,031		)		(4,013		)
Retiree contributions	1,111				1,056
Retiree contributions	1,111				1,056
Benefit obligation at end of year	100,700				92,847
Benefit obligation at end of year	100,700				92,847
Change in plan assets:
Fair value of plan assets at end of prior year	42,192				36,510
Fair value of plan assets at end of prior year	42,192				36,510
Actual return on plan assets	2,086				5,539
Actual return on plan assets	2,086				5,539
Employer contribution	—				3,100
Employer contribution	—				3,100
Benefits paid	(4,031		)		(4,013		)
Retiree contributions	1,111				1,056
Retiree contributions	1,111				1,056
Fair value of plan assets at end of year	41,358				42,192
Fair value of plan assets at end of year	41,358				42,192
Funded status at end of year	$	(59,342	)		$	(50,655	)
_____________________

(a)	Amendment relates to modification of the Company's Other Post-retirement Benefit Plan which limits the Company's premium contribution. The amendment became effective October 3, 2013 and resulted in a remeasurement of the plan.
Amounts recognized in the Company's balance sheets consist of the following (in thousands):


	December 31,
	2014				2013
Current liabilities	$	—			$	—
Current liabilities	$	—			$	—
Noncurrent liabilities	(59,342		)		(50,655		)
Total	$	(59,342	)		$	(50,655	)
Amounts recognized in accumulated other comprehensive income consist of the following (in thousands):



	December 31,
	2014				2013
Net gain	$	(31,943	)		$	(38,110	)
Prior service benefit	(14,457		)		(19,210		)
Total	$	(46,400	)		$	(57,320	)
The following are the weighted-average actuarial assumptions used to determine the accrued post-retirement benefit obligations:



	December 31,
	2014			2013
Discount rate at end of year	4.1	%		4.9	%
Health care cost trend rates:
Initial	7.25	%		7.5	%
Ultimate	4.5	%		4.5	%
Year ultimate reached	2026			2026
Year ultimate reached	2026			2026
The discount rate is reviewed at each measurement date. The discount rate used to measure obligations is based on a spot rate yield curve that matches projected future payments with the appropriate interest rate applicable to the timing of the projected future benefit payments. A 1% increase in the discount rate would decrease the December 31, 2014 accumulated post-retirement benefit obligation by 13.5%. A 1% decrease in the discount rate would increase the December 31, 2014 accumulated post-retirement benefit obligation by 17.2%.

Net periodic benefit cost is made up of the components listed below (in thousands):


	Years Ended December 31,
	2014				2013				2012
Service cost	$	2,845			$	3,843			$	4,378
Service cost	$	2,845			$	3,843			$	4,378
Interest cost	4,463				5,156				5,651
Interest cost	4,463				5,156				5,651
Expected return on plan assets	(2,116		)		(1,951		)		(1,714		)
Amortization of:
Prior service benefit	(4,753		)		(5,657		)		(5,877		)
Net (gain) loss	(2,671		)		(626		)		615
Net (gain) loss	(2,671		)		(626		)		615
Net periodic benefit cost	$	(2,232	)		$	765			$	3,053
Net periodic benefit cost	$	(2,232	)		$	765			$	3,053
The changes in benefit obligations recognized in other comprehensive income are presented below (in thousands):


	Years Ended December 31,
	2014				2013				2012
Net (gain) loss	$	3,496			$	(52,366	)		$	(5,900	)
Net (gain) loss	$	3,496			$	(52,366	)		$	(5,900	)
Prior service benefit	—				(97		)		—
Prior service benefit	—				(97		)		—
Amortization of:
Prior service benefit	4,753				5,657				5,877
Prior service benefit	4,753				5,657				5,877
Net gain (loss)	2,671				626				(615		)
Net gain (loss)	2,671				626				(615		)
Total recognized in other comprehensive income	$	10,920			$	(46,180	)		$	(638	)
Total recognized in other comprehensive income	$	10,920			$	(46,180	)		$	(638	)
The total amount recognized in net periodic benefit cost and other comprehensive income are presented below (in thousands):


	Years Ended December 31,
	2014				2013				2012
Total recognized in net periodic benefit cost and other comprehensive income	$	8,688			$	(45,415	)		$	2,415
	$	8,688			$	(45,415	)		$	2,415
The amount in accumulated other comprehensive income that is expected to be recognized as a component of net periodic benefit cost during 2015 is a prior service benefit of $3.1 million and a net gain of $2.0 million.
The following are the weighted-average actuarial assumptions used to determine the net periodic benefit cost for the twelve months ended December 31:


	2014			2013 (a)			2012
Discount rate at beginning of year	4.9	%		4.1	%		4.3	%
Expected long-term return on plan assets	5.2	%		5.2	%		5.2	%
Health care cost trend rates:
Initial	7.5	%		7.75	%		8	%
Ultimate	4.5	%		4.5	%		4.5	%
Year ultimate reached	2026			2026			2026
Year ultimate reached	2026			2026			2026
_____________________
(a) The Other Post-retirement Benefits Plan was remeasured at October 3, 2013 due to a plan amendment. The discount rate increased from 4.1% as of January 1, 2013 to 4.9% at the remeasurement date. All other assumptions remained consistent with assumptions used at January 1, 2013.
For measurement purposes, a 7.5% annual rate of increase in the per capita cost of covered health care benefits was assumed for 2014. The rate was assumed to decrease gradually to 4.5% for 2026 and remain at that level thereafter. Assumed health care cost trend rates have a significant effect on the amounts reported for the health care plan. The effect of a 1% change in these assumed health care cost trend rates would increase or decrease the December 31, 2014 benefit obligation by $16.1 million or $12.9 million, respectively. In addition, a 1% change in said rate would increase or decrease the aggregate 2014 service and interest cost components of the net periodic benefit cost by $1.4 million or $1.1 million, respectively.
The Company’s overall expected long-term rate of return on assets, on an after-tax basis, is 5.2% effective January 1, 2014. The expected long-term rate of return is based on the after-tax weighted average of the expected returns on investments based upon the target asset allocation. The Company’s target allocations for the plan’s assets are presented below:


		December 31, 2014
Equity securities		65	%
Fixed income		30	%
Alternative investments		5	%
Total		100	%
The Other Post-retirement Benefit Plan invests the majority of its plan assets in common collective trusts which includes a diversified portfolio of domestic and international equity securities and fixed income securities. The asset portfolio also includes cash equivalents and a real estate limited partnership. The expected rates of return for the funds are assessed annually and are based on long-term relationships among major asset classes and the level of incremental returns that can be earned by the successful implementation of different active investment management strategies. Equity returns are based on estimates of long-term inflation rate, real rate of return, 10-year Treasury bond premium over cash and equity risk premium. Fixed income returns are based on maturity, long-term inflation, real rate of return and credit spreads.
FASB guidance on disclosure for other post-retirement benefit plans requires disclosure of fair value measurements of plan assets. To increase consistency and comparability in fair value measurements, FASB guidance on fair value measurements established a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three levels as follows:


•	Level 1 – Observable inputs that reflect quoted market prices for identical assets and liabilities in active markets. Prices or securities held in the mutual funds and underlying portfolios of the Other Post-retirement Benefits Plan are primarily obtained from independent pricing services. These prices are based on observable market data.


•	Level 2 – Inputs other than quoted market prices included in Level 1 that are observable for the asset or liability either directly or indirectly. The fair value of municipal securities-tax-exempt are reported at fair value based on evaluated prices that reflect observable market information, such as actual trade information of similar securities, adjusted for observable differences. The Common Collective Trusts are valued using the NAV provided by the administrator of the fund. The NAV price is quoted on a restrictive market although the underlying investments are traded on active markets.


•	Level 3 – Unobservable inputs using data that is not corroborated by market data. The fair value of the real estate limited partnership is reported at the NAV of the investment.
The fair value of the Company’s Other Post-retirement Benefits Plan assets at December 31, 2014 and 2013, and the level within the three levels of the fair value hierarchy defined by FASB guidance on fair value measurements are presented in the table below (in thousands):


Description of Securities	Fair Value as of				Quoted Prices				Significant				Significant
	December 31,				in Active				Other				Unobservable
	2014				Markets for				Observable				Inputs
					Identical Assets				Inputs				(Level 3)
					(Level 1)				(Level 2)
Cash and Cash Equivalents	$	1,100			$	1,100			$	—			$	—
Cash and Cash Equivalents	$	1,100			$	1,100			$	—			$	—
Common Collective Trusts (a)
Equity funds	26,399				—				26,399				—
Equity funds	26,399				—				26,399				—
Fixed income funds	12,219				—				12,219				—
Fixed income funds	12,219				—				12,219				—
Total Common Collective Trusts	38,618				—				38,618				—
Total Common Collective Trusts	38,618				—				38,618				—
Limited Partnership Interest in Real Estate (b)	1,640				—				—				1,640
Limited Partnership Interest in Real Estate (b)	1,640				—				—				1,640
Total Plan Investments	$	41,358			$	1,100			$	38,618			$	1,640
Total Plan Investments	$	41,358			$	1,100			$	38,618			$	1,640

Description of Securities	Fair Value as of				Quoted Prices				Significant				Significant
	December 31,				in Active				Other				Unobservable
	2013				Markets for				Observable				Inputs
					Identical Assets				Inputs				(Level 3)
					(Level 1)				(Level 2)
Cash and Cash Equivalents	$	33			$	33			$	—			$	—
Cash and Cash Equivalents	$	33			$	33			$	—			$	—
Common Collective Trust (a)
Equity funds	28,077				—				28,077				—
Equity funds	28,077				—				28,077				—
Fixed income funds	12,421				—				12,421				—
Fixed income funds	12,421				—				12,421				—
Total Common Collective Trusts	40,498				—				40,498				—
Total Common Collective Trusts	40,498				—				40,498				—
Limited Partnership Interest in Real Estate (b)	1,661				—				—				1,661
Limited Partnership Interest in Real Estate (b)	1,661				—				—				1,661
Total Plan Investments	$	42,192			$	33			$	40,498			$	1,661
Total Plan Investments	$	42,192			$	33			$	40,498			$	1,661
___________________

(a)	The Common Collective Trusts are invested in equity or fixed income securities, or a combination thereof. The investment objective of each trust is to produce returns in excess of, or commensurate with, its predefined index.

(b)	This investment is a commercial real estate partnership that purchases land, develops limited infrastructure, and sells it for commercial development. The Company is restricted from selling its partnership interest during the life of the partnership which is generally 5-7 years. Return of investment is realized as land is sold. The fair value of the limited partnership interest in real estate is based on the NAV of the partnership which reflects the appraised value of the land.
The table below reflects the changes in the fair value of the investments in real estate during the period (in thousands):



	Fair Value of
	Investments in
	Real Estate
Balance at December 31, 2012	$	1,605
Balance at December 31, 2012	$	1,605
Unrealized gain in fair value	56
Unrealized gain in fair value	56
Balance at December 31, 2013	1,661
Balance at December 31, 2013	1,661
Sale of land	(67		)
Unrealized gain in fair value	46
Unrealized gain in fair value	46
Balance at December 31, 2014	$	1,640
Balance at December 31, 2014	$	1,640

There were no transfers in or out of Level 1 and Level 2 fair value measurements categories due to changes in observable inputs during the twelve month periods ending December 31, 2014 and 2013. Except as noted in the above table, there were no purchases, issuances, and settlements related to the assets in the Level 3 fair value measurement category during the twelve month periods ending December 31, 2014 and 2013.
The Company adheres to the traditional capital market pricing theory which maintains that over the long term, the risk of owning equities should be rewarded with a greater return than available from fixed income investments. The Company seeks to minimize the risk of owning equity securities by investing in funds that pursue risk minimization strategies and by diversifying its investments to limit its risks during falling markets. The investment manager has full discretionary authority to direct the investment of plan assets held in trust within the guidelines prescribed by the Company through the plan’s investment policy statement including the ability to hold cash equivalents. The investment guidelines of the investment policy statement are in accordance with the ERISA and DOL regulations.
The Company does not expect to contribute to its other post-retirement benefits plan in 2015. The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid (in thousands):



2015	$	3,163
2015	$	3,163
2016	3,528
2016	3,528
2017	3,906
2017	3,906
2018	4,303
2018	4,303
2019	4,570
2019	4,570
2020-2024	27,362
2020-2024	27,362

Annual Short-Term Incentive Plan
The Annual Short-Term Incentive Plan (the "Incentive Plan") provides for the payment of cash awards to eligible Company employees, including each of its named executive officers. Payment of awards is based on the achievement of performance measures reviewed and approved by the Company’s Board of Directors’ Compensation Committee. Generally, these performance measures are based on meeting certain financial, operational and individual performance criteria. The financial performance goals are based on earnings per share and the operational performance goals are based on safety, compliance, customer satisfaction, and reliability. If a specified level of earnings per share is not attained, no amounts will be paid under the Incentive Plan. In 2014, the Company reached the required levels of earnings per share, safety, compliance, and customer satisfaction goals for an incentive payment of $7.4 million. In 2013 and 2012, the Company reached the required levels of earnings per share, safety, regulatory compliance, and customer satisfaction goals for an incentive payment of $4.0 million and $7.9 million, respectively. The Company has renewed the Incentive Plan in 2015 with similar goals.

Franchises_and_Significant_Cus

Franchises and Significant Customers	12 Months Ended
	Dec. 31, 2014
Franchises and Significant Customers [Abstract]
Franchises And Significant Customers	Franchises and Significant Customers

	El Paso and Las Cruces Franchises
	The Company has a franchise agreement with El Paso, the largest city it serves. The franchise agreement allows the Company to utilize public rights-of-way necessary to serve its retail customers within El Paso. The Company is also providing electric distribution service to Las Cruces under an implied franchise by satisfying all obligations under the franchise agreement that expired on April 30, 2009.
	The franchise arrangements held between the Company and the cities of El Paso and Las Cruces are detailed below:


	City	Period	Franchise Fee	(a)
	El Paso	August 1, 2010 - Present	4.00%	(b)
	Las Cruces	February 1, 2000 - Present	2.00%
	_________________
	(a) Based on a percentage of revenue.
	(b) 0.75% of the El Paso franchise fee is to be placed in a restricted fund to be used solely for economic development and renewable energy purposes.
	Military Installations
	The Company serves Holloman Air Force Base ("Holloman"), White Sands Missile Range ("White Sands") and Fort Bliss. The military installations represent approximately 5% of the Company's annual retail revenues. In July 2014, the Company signed an agreement with Fort Bliss for an initial three-year term under which Fort Bliss takes retail electric service from the Company under the applicable Texas tariffs. The Company is serving White Sands under the applicable New Mexico tariffs. In March 2006, the Company signed a contract with Holloman that provides for the Company to provide retail electric service and limited wheeling services to Holloman for a ten-year term which expires in January 2016.

Financial_Instruments_and_Inve

Financial Instruments and Investments (Notes)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Financial Instruments and Investments	Financial Instruments and Investments
	FASB guidance requires the Company to disclose estimated fair values for its financial instruments. The Company has determined that cash and temporary investments, investment in debt securities, accounts receivable, decommissioning trust funds, long-term debt, short-term borrowings under the RCF, accounts payable and customer deposits meet the definition of financial instruments. The carrying amounts of cash and temporary investments, accounts receivable, accounts payable and customer deposits approximate fair value because of the short maturity of these items. Investments in debt securities and decommissioning trust funds are carried at fair value.
	Long-Term Debt and Short-Term Borrowings Under the RCF. The fair values of the Company's long-term debt and short-term borrowings under the RCF are based on estimated market prices for similar issues and are presented below (in thousands):


		December 31,
		2014							2013
		Carrying			Estimated				Carrying			Estimated
		Amount			Fair Value				Amount			Fair Value
	Pollution Control Bonds	$	193,135		$	213,083			$	193,135		$	193,990

	Senior Notes	846,044			968,728				696,485			734,515

	RGRT Senior Notes (1)	110,000			117,215				110,000			115,850

	RCF (1)	14,532			14,532				14,352			14,352

	Total	$	1,163,711		$	1,313,558			$	1,013,972		$	1,058,707

	__________________

	-1	Nuclear fuel financing as of December 31, 2014 and December 31, 2013 is funded through the $110 million RGRT Senior Notes and $14.5 million and $14.4 million, respectively under the RCF. As of December 31, 2014 and 2013, no amount was outstanding under the RCF for working capital or general corporate purposes. The interest rate on the Company’s borrowings under the RCF is reset throughout the period reflecting current market rates. Consequently, the carrying value approximates fair value.
	Treasury Rate Locks. The Company entered into treasury rate lock agreements in 2005 to hedge against potential movements in the treasury reference interest rate pending the issuance of the 6% Senior Notes. The treasury rate lock agreements met the criteria for hedge accounting and were designated as a cash flow hedge. In accordance with cash flow hedge accounting, the Company recorded the loss associated with the fair value of the cash flow hedge, net of tax, as a component of accumulated other comprehensive loss and amortizes the accumulated comprehensive loss to earnings as interest expense over the life of the 6% Senior Notes. In 2015, approximately $0.5 million of this accumulated other comprehensive loss item will be reclassified to interest expense.
	Contracts and Derivative Accounting. The Company uses commodity contracts to manage its exposure to price and availability risks for fuel purchases and power sales and purchases and these contracts generally have the characteristics of derivatives. The Company does not trade or use these instruments with the objective of earning financial gains on the commodity price fluctuations. The Company has determined that all such contracts outstanding at December 31, 2014, except for certain natural gas commodity contracts with optionality features, that had the characteristics of derivatives met the "normal purchases and normal sales" exception provided in FASB guidance for accounting for derivative instruments and hedging activities, and, as such, were not required to be accounted for as derivatives.
	The Company determined that certain of its natural gas commodity contracts with optionality features are not eligible for the normal purchases exception and, therefore, are required to be accounted for as derivative instruments pursuant to FASB guidance for accounting for derivative instruments and hedging activities. However, as of December 31, 2014, the variable, market-based pricing provisions of existing gas contracts are such that these derivative instruments have no significant fair value.
	Marketable Securities. The Company’s marketable securities, included in decommissioning trust funds in the balance sheets, are reported at fair value which was $234.3 million and $214.1 million at December 31, 2014 and 2013, respectively. These securities are classified as available for sale under FASB guidance for certain investments in debt and equity securities and are valued using prices and other relevant information generated by market transactions involving identical or comparable securities. The reported fair values include gross unrealized losses on marketable securities whose impairment the Company has deemed to be temporary. The tables below present the gross unrealized losses and the fair value of these securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position (in thousands):



		December 31, 2014
		Less than 12 Months							12 Months or Longer							Total
		Fair			Unrealized				Fair			Unrealized				Fair			Unrealized
		Value			Losses				Value			Losses				Value			Losses
	Description of Securities (1):
	Federal Agency Mortgage Backed Securities	$	—		$	—			$	2,383		$	(57	)		$	2,383		$	(57	)

	U.S. Government Bonds	1,552			(2		)		20,060			(573		)		21,612			(575		)

	Municipal Obligations	6,433			(65		)		8,570			(410		)		15,003			(475		)

	Corporate Obligations	2,455			(24		)		2,461			(111		)		4,916			(135		)

	Total Debt Securities	10,440			(91		)		33,474			(1,151		)		43,914			(1,242		)

	Common Stock	1,475			(229		)		—			—				1,475			(229		)

	Common Collective Trust-Equity Funds	22,736			(821		)		—			—				22,736			(821		)

	Total Temporarily Impaired Securities	$	34,651		$	(1,141	)		$	33,474		$	(1,151	)		$	68,125		$	(2,292	)

	____________________

	-1	Includes approximately 106 securities.


		December 31, 2013
		Less than 12 Months							12 Months or Longer							Total
		Fair			Unrealized				Fair			Unrealized				Fair			Unrealized
		Value			Losses				Value			Losses				Value			Losses
	Description of Securities (2):
	Federal Agency Mortgage Backed Securities	$	6,444		$	(169	)		$	1,421		$	(119	)		$	7,865		$	(288	)

	U.S. Government Bonds	8,114			(245		)		10,866			(840		)		18,980			(1,085		)

Municipal Obligations	12,286			(335		)		7,782			(479		)		20,068			(814		)

Corporate Obligations	3,284			(96		)		901			(54		)		4,185			(150		)

Total Debt Securities	30,128			(845		)		20,970			(1,492		)		51,098			(2,337		)

Common stock	2,305			(126		)		—			—				2,305			(126		)

Total Temporarily Impaired Securities	$	32,433		$	(971	)		$	20,970		$	(1,492	)		$	53,403		$	(2,463	)

______________________

-2	Includes approximately 122 securities.
The Company monitors the length of time the security trades below its cost basis along with the amount and percentage of the unrealized loss in determining if a decline in fair value of marketable securities below recorded cost is considered to be other than temporary. In addition, the Company will research the future prospects of individual securities as necessary. As a result of these factors, as well as the Company’s intent and ability to hold these securities until their market price recovers, these securities are considered temporarily impaired. The Company does not anticipate expending monies held in trust before 2044 or a later period when the Company begins to decommission Palo Verde.








The reported fair values also include gross unrealized gains on marketable securities which have not been recognized in the Company’s net income. The table below presents the unrecognized gross unrealized gains and the fair value of these securities, aggregated by investment category (in thousands):



	December 31, 2014							December 31, 2013
	Fair			Unrealized				Fair			Unrealized
	Value			Gains				Value			Gains
Description of Securities:
Federal Agency Mortgage Backed Securities	$	15,388		$	665			$	9,929		$	433

U.S. Government Bonds	20,016			567				6,258			126

Municipal Obligations	11,642			595				8,783			450

Corporate Obligations	13,762			850				9,188			506

Total Debt Securities	60,808			2,677				34,158			1,515

Common Stock	99,160			48,253				103,808			43,145

Equity Mutual Funds	—			—				16,802			3,081

Cash and Cash Equivalents	6,193			—				5,924			—

Total	$	166,161		$	50,930			$	160,692		$	47,741

The Company’s marketable securities include investments in municipal, corporate and federal debt obligations. Substantially all of the Company’s mortgage-backed securities, based on contractual maturity, are due in ten years or more. The mortgage-backed securities have an estimated weighted average maturity which generally range from two years to six years and reflects anticipated future prepayments. The contractual year for maturity for these available-for-sale securities as of December 31, 2014 is as follows (in thousands):


	Total			2015				2016			2020 through 2024				2025 and Beyond
								through
								2019
Municipal Debt Obligations	$	26,645		$	1,011			$	11,318		$	12,967			$	1,349

Corporate Debt Obligations	18,678			720				5,163			6,517				6,278

U.S. Government Bonds	41,628			3,050				17,520			12,062				8,996

The Company recognizes impairment losses on certain of its securities deemed to be other than temporary. In accordance with FASB guidance, these impairment losses are recognized in net income, and a lower cost basis is established for these securities. For the twelve months ended December 31, 2014, 2013, and 2012 the Company recognized other than temporary impairment losses on its available-for-sale securities as follows (in thousands):


	2014			2013				2012
Unrealized holding losses included in pre-tax income	$	—		$	—			$	(479	)



The Company’s marketable securities in its decommissioning trust funds are sold from time to time and the Company uses the specific identification basis to determine the amount to reclassify out of accumulated other comprehensive income and into net income. The proceeds from the sale of these securities during the twelve months ended December 31, 2014, 2013, and 2012 and the related effects on pre-tax income are as follows (in thousands):


	2014			2013				2012
Proceeds from sales or maturities of available-for-sale securities	$	108,311		$	56,148			$	98,542

Gross realized gains included in pre-tax income	$	7,858		$	986			$	1,478

Gross realized losses included in pre-tax income	(508		)	(433		)		(2,041		)
Gross unrealized losses included in pre-tax income	—			—				(479		)

Net gains (losses) in pre-tax income	$	7,350		$	553			$	(1,042	)

Net unrealized holding gains included in accumulated other comprehensive income	$	10,827		$	17,699			$	9,927

Net (gains) losses reclassified out of accumulated other comprehensive income	(7,350		)	(553		)		1,042

Net gains in other comprehensive income	$	3,477		$	17,146			$	10,969

Fair Value Measurements. FASB guidance requires the Company to provide expanded quantitative disclosures for financial assets and liabilities recorded on the balance sheet at fair value. Financial assets carried at fair value include the Company's decommissioning trust investments and investments in debt securities which are included in deferred charges and other assets on the balance sheets. The Company has no liabilities that are measured at fair value on a recurring basis. The FASB guidance establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three levels as follows:


•	Level 1 - Observable inputs that reflect quoted market prices for identical assets and liabilities in active markets. Financial assets utilizing Level 1 inputs include the nuclear decommissioning trust investments in active exchange-traded equity securities, mutual funds and U.S. Treasury securities that are in a highly liquid and active market.

•	Level 2 - Inputs other than quoted market prices included in Level 1 that are observable for the asset or liability either directly or indirectly. Financial assets utilizing Level 2 inputs include the nuclear decommissioning trust investments in fixed income securities. The fair value of these financial instruments is based on evaluated prices that reflect observable market information, such as actual trade information of similar securities, adjusted for observable differences. The Common Collective Trusts are valued using the net asset value ("NAV") provided by the administrator of the fund. The NAV price is quoted on a restrictive market although the underlying investments are traded on active markets.

•	Level 3 - Unobservable inputs using data that is not corroborated by market data and primarily based on internal Company analysis using models and various other analysis. Financial assets utilizing Level 3 inputs include the Company's investments in debt securities.
The securities in the Company’s decommissioning trust funds are valued using prices and other relevant information generated by market transactions involving identical or comparable securities. FASB guidance identifies this valuation technique as the "market approach" with observable inputs. The Company analyzes available-for-sale securities to determine if losses are other than temporary.







During the first quarter of 2014, the Company sold its nuclear decommissioning trust investments in equity mutual funds, classified as Level 1, and invested those assets in common collective trusts which are classified as Level 2. The fair value of the Company’s decommissioning trust funds and investments in debt securities, at December 31, 2014 and 2013, and the level within the three levels of the fair value hierarchy defined by FASB guidance are presented in the table below (in thousands):


Description of Securities		Fair Value as of			Quoted Prices				Significant			Significant
		December 31,			in Active				Other			Unobservable
		2014			Markets for				Observable			Inputs
					Identical Assets				Inputs			(Level 3)
					(Level 1)				(Level 2)
Trading Securities:
Investments in Debt Securities		$	1,653		$	—			$	—		$	1,653

Available for sale:
U.S. Government Bonds		$	41,628		$	41,628			$	—		$	—

Federal Agency Mortgage Backed Securities		17,771			—				17,771			—

Municipal Obligations		26,645			—				26,645			—

Corporate Obligations		18,678			—				18,678			—

Subtotal, Debt Securities		104,722			41,628				63,094			—

Common Stock		100,635			100,635				—			—

Common Collective Trust-Equity Funds		22,736			—				22,736			—

Cash and Cash Equivalents		6,193			6,193				—			—

Total available for sale		$	234,286		$	148,456			$	85,830		$	—




Description of Securities	Fair Value as of			Quoted Prices				Significant			Significant
	December 31,			in Active				Other			Unobservable
	2013			Markets for				Observable			Inputs
				Identical Assets				Inputs			(Level 3)
				(Level 1)				(Level 2)
Trading Securities:
Investments in Debt Securities	$	1,555		$	—			$	—		$	1,555

Available for sale:
U.S. Government Bonds	$	25,238		$	25,238			$	—		$	—

Federal Agency Mortgage Backed Securities	17,794			—				17,794			—

Municipal Obligations	28,851			—				28,851			—

Corporate Obligations	13,373			—				13,373			—

Subtotal, Debt Securities	85,256			25,238				60,018			—

Common Stock	106,113			106,113				—			—

Equity Mutual Funds	16,802			16,802				—			—

Cash and Cash Equivalents	5,924			5,924				—			—

Total available for sale	$	214,095		$	154,077			$	60,018		$	—

Below is a reconciliation of the beginning and ending balance of the fair value of the investment in debt securities (in thousands):


	2014			2013
Balance at January 1	$	1,555		$	1,295

Net unrealized gains in fair value recognized in income (a)	98			260

Balance at December 31	$	1,653		$	1,555

_____________________
(a) These amounts are reflected in the Company's statement of operations as investment and interest income.
There were no transfers in or out of Level 1 and Level 2 fair value measurements categories due to changes in observable inputs during the twelve month periods ending December 31, 2014 and 2013. There were no purchases, sales, issuances, and settlements related to the assets in the Level 3 fair value measurement category during the twelve month periods ending December 31, 2014 and 2013.

Supplemental_Statements_of_Cas

Supplemental Statements of Cash Flows Disclosures	12 Months Ended
	Dec. 31, 2014
Supplemental Cash Flow Information [Abstract]
Cash Flow, Supplemental Disclosures	Supplemental Statements of Cash Flows Disclosures


		Years Ended December 31,
		2014		2013		2012
		(In thousands)
	Cash paid for:
	Interest on long-term debt and borrowing under the revolving credit facility	$	54,792	$	53,752	$	50,189

	Income taxes, net of refund	6,876		244		5,031

	Non-cash financing activities:
	Grants of restricted shares of common stock	3,025		3,224		2,411

	Issuance of performance shares	—		849		1,193

Selected_Quarterly_Financial_D

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2014
Selected Quarterly Financial Data
Quarterly Financial Information	Selected Quarterly Financial Data (Unaudited)
	The following table summarizes the Company’s unaudited results of operations on a quarterly basis. The quarterly earnings per share amounts for a year will not add to the earnings per share for that year due to the weighting of shares used in calculating per share data.



		2014 Quarters								2013 Quarters
		4th		3rd		2nd		1st		4th		3rd		2nd		1st
						(In thousands except for share data)
	Operating revenues (1)	$	196,563	$	283,645	$	251,801	$	185,516	$	190,297	$	282,661	$	240,114	$	177,290

	Operating income	8,871		81,496		51,131		9,665		6,050		85,896		54,344		19,345

	Net income	4,241		52,476		30,096		4,615		1,191		50,565		29,193		7,634

	Basic earnings per share:
	Net income	0.1		1.3		0.75		0.11		0.03		1.26		0.73		0.19

	Diluted earnings per share:
	Net income	0.1		1.3		0.75		0.11		0.03		1.26		0.72		0.19

	Dividends declared per share of common stock	0.28		0.28		0.28		0.265		0.265		0.265		0.265		0.25

	________________

	-1	Operating revenues are seasonal in nature, with the peak sales periods generally occurring during the summer months. Comparisons among quarters of a year may not represent overall trends and changes in operations.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2014

Accounting Policies [Abstract]

Basis of Accounting, Policy

Basis of Presentation. The Company maintains its accounts in accordance with the Uniform System of Accounts prescribed by the Federal Energy Regulatory Commission (the "FERC").

Use of Estimates

Use of Estimates. The preparation of financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

Application of FASB Guidance for Regulated Operations

Application of FASB Guidance for Regulated Operations. Regulated electric utilities typically prepare their financial statements in accordance with the Financial Accounting Standards Board ("FASB") guidance for regulated operations. FASB guidance for regulated operations requires the Company to include an allowance for equity and borrowed funds used during construction ("AEFUDC" and "ABFUDC") as a cost of construction of electric plant in service. AEFUDC is recognized as income and ABFUDC is shown as capitalized interest charges in the Company’s statement of operations. FASB guidance for regulated operations also requires the Company to show certain recoverable costs as either assets or liabilities on a utility’s balance sheet if the regulator provides assurance that these costs will be charged to and collected from the utility’s customers (or has already permitted such cost recovery) or will be credited or refunded to the utility’s customers. The resulting regulatory assets or liabilities are amortized in subsequent periods based upon the respective amortization periods reflected in a utility’s regulated rates. See Note D. The Company applies FASB guidance for regulated operations for all three of the jurisdictions in which it operates.

Comprehensive Income

Comprehensive Income. Certain gains and losses that are not recognized currently in the statements of operations are reported as other comprehensive income in accordance with FASB guidance for reporting comprehensive income.

Utility plant

Utility Plant. Utility plant is generally reported at cost. The cost of renewals and betterments are capitalized and the costs of repairs and minor replacements are charged to the appropriate operating expense accounts. Depreciation is provided on a straight-line basis over the estimated remaining lives of the assets (ranging in average from 5 to 48 years). The average composite depreciation rate utilized in 2014, 2013 and 2012 was 2.60%, 2.61%, and 2.64%, respectively. When property subject to composite depreciation is retired or otherwise disposed of in the normal course of business, its cost – together with the cost of removal, less salvage – is charged to accumulated depreciation. For other property dispositions, the applicable cost and accumulated depreciation is removed from the balance sheet accounts and a gain or loss is recognized.

The cost of nuclear fuel is amortized to fuel expense on a units-of-production basis. The Company is also amortizing its share of costs associated with on-site spent fuel storage casks at Palo Verde over the burn period of the fuel that will necessitate the use of the storage casks. See Note E.

Impairment of Long-Lived Assets

Impairment of Long-Lived Assets. Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated undiscounted future cash flows, an impairment charge is recognized for the amount by which the carrying amount of the asset exceeds the fair value of the asset.

AFUDC and Capitalized Interest

AFUDC and Capitalized Interest. The Company capitalizes interest ("ABFUDC") and common equity ("AEFUDC") costs to construction work in progress and capitalizes interest to nuclear fuel in process in accordance with the FERC Uniform System of Accounts as provided for in FASB guidance. AFUDC is a non-cash component of income and is calculated monthly and charged to all new eligible construction and capital improvement projects. AFUDC is compounded on a semi-annual basis. The AFUDC rates used in 2014, 2013 and 2012 were 8.15%, 8.10% and 8.53%, respectively.

Asset Retirement Obligation

Asset Retirement Obligation. FASB guidance sets forth accounting requirements for the recognition and measurement of liabilities associated with the retirement of tangible long-lived assets. An asset retirement obligation ("ARO") associated with long-lived assets included within the scope of FASB guidance is that for which a legal obligation exists under enacted laws, statutes, written or oral contracts, including obligations arising under the doctrine of promissory estoppel and legal obligations to perform an asset retirement activity even if the timing and/or settlement are conditioned on a future event that may or may not be within the control of an entity. See Note F. Under FASB guidance, these liabilities are recognized as incurred if a reasonable estimate of fair value can be established and are capitalized as part of the cost of the related tangible long-lived assets. The Company records the increase in the ARO due to the passage of time as an operating expense (accretion expense).

Cash and Cash Equivalents

Cash and Cash Equivalents. All temporary cash investments with an original maturity of three months or less are considered cash equivalents.

Investments

Investments. The Company’s marketable securities, included in decommissioning trust funds in the balance sheets, are reported at fair value and consist of cash, equity securities and municipal, federal and corporate bonds in trust funds established for decommissioning of its interest in Palo Verde. Such marketable securities are classified as "available-for-sale" securities and, as such, unrealized gains and losses are included in accumulated other comprehensive loss as a separate component of common stock equity. However, if declines in fair value of marketable securities below original cost basis are determined to be other than temporary, then the declines are reported as losses in the statement of operations and a new cost basis is established for the affected securities at fair value. Gains and losses are determined using the cost of the security based on the specific identification basis. See Note O.

Derivative Accounting

Derivative Accounting. Accounting for derivative instruments and hedging activities requires the recognition of derivatives as either assets or liabilities in the balance sheet with measurement of those instruments at fair value. Any changes in the fair value of these instruments are recorded in earnings or other comprehensive income. See Note O.

Inventories

Inventories. Inventories, primarily parts, materials, supplies, fuel oil and natural gas are stated at average cost not to exceed recoverable cost.

Operating Revenues Net of Energy Expenses

Operating Revenues Net of Energy Expenses. The Company accrues revenues for services rendered, including unbilled electric service revenues. Energy expenses are stated at actual cost incurred. The Company’s Texas retail customers are billed under base rates and a fixed fuel factor approved by the Public Utility Commission of Texas ("PUCT"). The Company’s New Mexico retail customers are billed under base rates and a fuel adjustment clause which is adjusted monthly, as approved by the New Mexico Public Regulation Commission ("NMPRC"). The Company's FERC sales for resale customers are billed under formula base rates and fuel factors and a fuel adjustment clause which is adjusted monthly. The Company’s recovery of energy expenses is subject to periodic reconciliations of actual energy expenses incurred to actual fuel revenues collected. The difference between energy expenses incurred and fuel revenues charged to customers is reflected as over/under-collection of fuel revenues in the balance sheets. See Note C.

Revenues. Revenues related to the sale of electricity are generally recorded when service is rendered or electricity is delivered to customers. The billing of electricity sales to retail customers is based on the reading of their meters, which occurs on a systematic basis throughout the month. Unbilled revenues are estimated based on monthly generation volumes and by applying an average revenue/kWh to the number of estimated kWhs delivered but not billed. Accounts receivable included accrued unbilled revenues of $21.2 million and $19.8 million at December 31, 2014 and 2013, respectively. The Company presents revenues net of sales taxes in its statements of operations.

Allowance for Doubtful Accounts

Allowance for Doubtful Accounts. The allowance for doubtful accounts represents the Company’s estimate of existing accounts receivable that will ultimately be uncollectible. The allowance is calculated by applying estimated write-off factors to various classes of outstanding receivables. The write-off factors used to estimate uncollectible accounts are based upon consideration of both historical collections experience and management’s best estimate of future collections success given the existing collections environment. Additions, deductions and balances for allowance for doubtful accounts for 2014, 2013 and 2012 are as follows (in thousands):

2014

2013

2012

Balance at beginning of year

2,261

2,906

3,015

Additions:

Charged to costs and expense

2,755

2,098

3,087

Recovery of previous write-offs

1,516

1,929

2,041

Uncollectible receivables written off

4,279

4,672

5,237

Balance at end of year

2,253

2,261

2,906

Income Taxes

Income Taxes. The Company accounts for federal and state income taxes under the asset and liability method of accounting for income taxes. Deferred income taxes are recognized for the estimated future tax consequences of "temporary differences" by applying enacted statutory tax rates for each taxable jurisdiction applicable to future years to differences between the financial statement carrying amounts and the tax basis of existing assets and liabilities. Certain temporary differences are accorded flow-through treatment by the Company's regulators and impact the Company's effective tax rate. FASB guidance requires that rate-regulated companies record deferred income taxes for temporary differences accorded flow-through treatment at the direction of the regulatory commission. The resulting deferred tax assets and liabilities are recorded at the expected cash flow to be reflected in future rates. Because the Company's regulators have consistently permitted the recovery of tax effects previously flowed-through earnings, the Company has recorded regulatory liabilities and assets offsetting such deferred tax assets and liabilities. The effect on deferred tax assets and liabilities of a change in tax rate is recognized in income in the period that includes the enactment date. The Company recognizes tax assets and liabilities for uncertain tax positions in accordance with the recognition and measurement criteria of FASB guidance for uncertainty in income taxes. See Note J.

Earnings Per Share

Earnings per Share. The Company’s restricted stock awards are participating securities and earnings per share must be calculated using the two-class method in both the basic and diluted earnings per share calculations. For the basic earnings per share calculation, net income is allocated to the weighted average number of restricted stock awards and to the weighted average number of shares outstanding. The net income allocated to the weighted average number of shares outstanding is then divided by the weighted average number of shares outstanding to derive the basic earnings per share. For the diluted earnings per share, net income is allocated to the weighted average number of restricted stock awards and to the weighted average number of shares and dilutive potential shares outstanding. The Company’s dilutive potential shares outstanding amount is calculated using the treasury stock method for the unvested performance shares. Net income allocated to the weighted average number of shares and dilutive potential shares is then divided by the weighted average number of shares and dilutive potential shares outstanding to derive the diluted earnings per share. See Note G.

Stock-Based Compensation

Stock-Based Compensation. The Company has a stock-based long-term incentive plan. The Company is required under FASB guidance to measure the cost of employee services received in exchange for an award of equity instruments based on the grant-date fair value of the award. Such costs are recognized over the period during which an employee is required to provide service in exchange for the award (the "requisite service period") which typically is the vesting period. Compensation cost is not recognized for anticipated forfeitures prior to vesting of equity instruments. See Note G.

Reclassifications

Reclassification. Certain amounts in the financial statements for 2013 and 2012 have been reclassified to conform with the 2014 presentation.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2014
Accounting Policies [Abstract]
Allowance for Doubtful Accounts Receivable	Additions, deductions and balances for allowance for doubtful accounts for 2014, 2013 and 2012 are as follows (in thousands):




		2014		2013		2012
	Balance at beginning of year	$	2,261	$	2,906	$	3,015

	Additions:
	Charged to costs and expense	2,755		2,098		3,087

	Recovery of previous write-offs	1,516		1,929		2,041

	Uncollectible receivables written off	4,279		4,672		5,237

	Balance at end of year	$	2,253	$	2,261	$	2,906

Regulatory_Assets_and_Liabilit1

Regulatory Assets and Liabilities Regulatory Assets and Liabilities (Tables)	12 Months Ended
	Dec. 31, 2014
Regulatory Assets and Liabilities Disclosure [Abstract]
Regulatory Assets and Liabilities [Table Text Block]	Regulatory assets and liabilities reflected in the Company's balance sheets are presented below (in thousands):


		Amortization	December 31, 2014		December 31, 2013
		Period Ends
	Regulatory assets
	Regulatory tax assets (a)	(b)	$	66,134	$	61,772

	Loss on reacquired debt (c)	May-35	17,486		18,338

	Final coal reclamation (d)	(e)	10,702		4,290

	Nuclear fuel postload daily financing charge	(d)	4,127		4,141

	Unrecovered issuance costs due to reissuance of PCBs (c)	Aug-42	860		893

	Texas energy efficiency	(f)	1,817		—

	Texas 2012 rate case costs	Apr-14	—		581

	Texas 2015 rate case costs	(g)	169		—

	Texas military base discount and recovery factor	(h)	—		759

	New Mexico procurement plan costs	(g)	139		139

	New Mexico renewable energy credits	(g)	5,456		4,833

	New Mexico 2010 FPPCAC audit	(g)	434		433

	New Mexico Palo Verde deferred depreciation	(b)	4,720		4,871

	New Mexico 2015 rate case costs	(g)	42		—

	Total regulatory assets		$	112,086	$	101,050

	Regulatory liabilities
	Regulatory tax liabilities (a)	(b)	$	17,252	$	17,752

	Accumulated deferred investment tax credit (i)	(b)	4,334		4,656

	New Mexico energy efficiency	(f)	3,904		3,646

	Texas energy efficiency	(f)	—		362

	Texas military base discount and recovery factor	(h)	609		—

	Total regulatory liabilities		$	26,099	$	26,416


	________________

	(a)	No specific return on investment is required since related assets and liabilities offset.

	(b)	The amortization period for this asset is based upon the life of the associated assets or liabilities.

	(c)	This item is recovered as a component of the weighted cost of debt and amortized over the life of the related debt issuance.

	(d)	This item is recovered through fuel recovery mechanisms.

	(e)	This item and the related final coal reclamation liability have been included or will be requested in rate base.

	(f)	This item is recovered or credited through a recovery factor that is set annually.

(g)	Amortization period is anticipated to be established in next general rate case.

(h)	This item represents the net asset/net liability related to the military discount which is recovered from non-military customers through a recovery factor.

(i)	This item is excluded from rate base.

Utility_Plant_Palo_Verde_and_O1

Utility Plant, Palo Verde and Other Jointly-Owned Utility Plant (Tables)	12 Months Ended
	Dec. 31, 2014
Utility Plant, Palo Verde and Other Jointly-Owned Utility Plant [Abstract]
Schedule of Property, Plant and Equipment and Finite-Lived Intangible Assets By Major Class	The table below presents the balance of each major class of depreciable assets at December 31, 2014 (in thousands):




		Gross			Accumulated			Net
		Plant			Depreciation			Plant
	Nuclear production	$	874,817		$	(286,585	)	$	588,232

	Steam and other	684,863			(284,764		)	400,099

	Total production	1,559,680			(571,349		)	988,331

	Transmission	433,982			(250,941		)	183,041

	Distribution	1,020,901			(342,931		)	677,970

	General	139,491			(56,412		)	83,079

	Intangible	75,201			(45,039		)	30,162

	Total	$	3,229,255		$	(1,266,672	)	$	1,962,583

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The table below presents the actual and estimated amortization expense for intangible plant for the previous three years and for the next five years (in thousands):




	2012	7,183

	2013	7,683

	2014	8,051

	2015 (estimated)	7,505

	2016 (estimated)	7,030

	2017 (estimated)	6,388

	2018 (estimated)	4,762

	2019 (estimated)	3,101

Schedule of Jointly Owned Utility Plants	A summary of the Company’s investment in jointly-owned utility plant, excluding fuel inventories, at December 31, 2014 and 2013 is as follows (in thousands):



		December 31, 2014						December 31, 2013
		Palo Verde			Other			Palo Verde			Other
	Electric plant in service	$	874,817		$	219,318		$	817,665		$	217,137

	Accumulated depreciation	(286,585		)	(176,492		)	(271,173		)	(173,819		)
	Construction work in progress	55,632			6,900			75,040			2,347

	Total	$	643,864		$	49,726		$	621,532		$	45,665

Accounting_for_Asset_Retiremen1

Accounting for Asset Retirement Obligations (Tables)	12 Months Ended
	Dec. 31, 2014
Accounting for Asset Retirement Obligations
Changes In Estimated Probabilities Assumptions	The assumptions used to calculate the Palo Verde ARO liability are as follows:



		Escalation		Credit-Risk
		Rate		Adjusted
				Discount Rate
	Original ARO liability	3.6	%	9.5	%
	Incremental ARO liability	3.6	%	6.2	%
Schedule of Asset Retirement Obligations


		2014			2013			2012
	ARO liability at beginning of year	$	65,214		$	62,784		$	56,140

	Liabilities incurred	—			—			—

	Liabilities settled	—			(36		)	(450		)

	Revisions to estimate	3,561			(3,401		)	1,929

	Accretion expense	5,802			5,867			5,165

	ARO liability at end of year	$	74,577		$	65,214		$	62,784

Common_Stock_Tables

Common Stock (Tables)	12 Months Ended
	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Treasury Stock by Class	Detail regarding the Company's stock repurchase program are presented below:


		Since 1999				Authorized
		(a)				Shares
	Shares repurchased (b)	25,406,184

	Cost, including commission (in thousands)	$	423,647

	Total remaining shares available for repurchase at December 31, 2014					393,816

	______________________

	(a)	Represents repurchased shares and cost since inception of the stock repurchase program in 1999.

	(b)	Shares repurchased does not include 86,735 treasury shares related to employee compensation arrangements outside of the Company's repurchase programs.
Schedule of Earnings Per Share, Basic and Diluted	The Company awards unvested restricted stock which qualifies as a participating security. The basic and diluted earnings per share are presented below:


		Years Ended December 31,
		2014				2013				2012
	Weighted average number of common shares outstanding:
	Basic number of common shares outstanding	40,190,991				40,114,594				39,974,022

	Dilutive effect of unvested performance awards	20,726				12,053				66,756

	Dilutive effect of stock options	—				—				14,803

	Diluted number of common shares outstanding	40,211,717				40,126,647				40,055,581

	Basic net income per common share:
	Net income	$	91,428			$	88,583			$	90,846

	Income allocated to participating restricted stock	(301		)		(254		)		(256		)
	Net income available to common shareholders	$	91,127			$	88,329			$	90,590

	Diluted net income per common share:
	Net income	$	91,428			$	88,583			$	90,846

	Income reallocated to participating restricted stock	(301		)		(254		)		(256		)
	Net income available to common shareholders	$	91,127			$	88,329			$	90,590

	Basic net income per common share:
	Distributed earnings	$	1.105			$	1.045			$	0.97

	Undistributed earnings	1.165				1.155				1.3

	Basic net income per common share	$	2.27			$	2.2			$	2.27

	Diluted net income per common share:
	Distributed earnings	$	1.105			$	1.045			$	0.97

	Undistributed earnings	1.165				1.155				1.29

	Diluted net income per common share	$	2.27			$	2.2			$	2.26

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share	The amount of restricted stock awards and performance shares at 100% performance level excluded from the calculation of the diluted number of common shares outstanding because their effect was antidilutive is presented below:


			Year Ended December 31,
			2014			2013			2012
	Restricted stock awards		60,455			51,489			45,178

	Performance shares (a)		96,208			115,044			57,625

	_____________________

	(a)	Certain performance shares were excluded from the computation of diluted earnings per share as no payouts would have been required based upon performance at the end of each corresponding period.
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Expense, Deferred Tax Benefit, and Current Tax Expense Related to Restricted Stock Awards	The expense, deferred tax benefit, and current tax expense recognized related to restricted stock awards and other stock-based awards in 2014, 2013 and 2012 is presented below (in thousands):


			2014				2013				2012

	Expense (a)		$	3,471			$	2,458			$	1,508

	Deferred tax benefit		1,215				860				528

	Current tax benefit recognized		39				109				94

	_____________________
	(a) Any capitalized costs related to these expenses is less than $0.1 million for all years.
Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity	The aggregate intrinsic value and fair value at grant date of restricted stock and other stock-based awards which vested in 2014, 2013 and 2012 is presented below (in thousands):


			2014				2013				2012

	Aggregated intrinsic value		$	3,441			$	2,077			$	2,242

	Fair value at grant date		3,330				1,765				1,973

Schedule of Nonvested Restricted Stock Units Activity	The unvested restricted stock and other stock-based award transactions for 2014 are presented below:


		Total			Weighted				Unrecognized Compensation Expense (a)				Aggregate Intrinsic Value
		Shares			Average
					Grant Date
					Fair Value
									(In thousands)				(In thousands)
	Restricted shares outstanding at December 31, 2013	120,534			$	35.19

	Stock awards	113,776			36.95

	Vested	(90,851	)		36.66

	Forfeitures	(19,162	)		34.72

	Restricted shares outstanding at December 31, 2014	124,297			35.81				$	1,662			$	4,979

	_______________________
	(a) The unrecognized compensation expense is expected to be recognized over the weighted average remaining contractual term of the outstanding restricted stock of approximately one year.
Schedule of Share-based Compensation Award, Restricted Stock, Grants in Period, Weighted Average Grant Date Fair Value	The weighted average fair value per share at grant date for restricted stock and other stock-base awards granted during 2014, 2013 and 2012 were:


		2014				2013				2012
	Weighted average fair value per share	$	36.95			$	35.48			$	32.45

Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Schedule of Share-based Compensation Award, Performance-Based Units, Vested and Expected to Vest	Detail of performance shares vested follows:


	Date Vested		Payout Ratio			Performance Shares Awarded			Compensation Costs Expensed				Period Compensation Costs Expensed		Aggregated Intrinsic Value
									(In thousands)						(In thousands)
	February 20, 2015		0	%		0			$	1,502			2012-2014		$	—

	February 18, 2014		0	%		0			954				2011-2013		—

	January 29, 2013		150	%		64,275			849				2010-2012		2,176

	January 1, 2012		175	%		174,038			1,193				2009-2011		6,029

Schedule of Share-based Compensation Arrangements by Share-based Payment Award	The outstanding performance share awards at the 100% performance level is summarized below:


		Number			Weighted				Unrecognized Compensation Expense (a)				Aggregate Intrinsic Value
		Outstanding			Average
					Grant Date
					Fair Value
									(In thousands)				(In thousands)
	Performance shares outstanding at December 31, 2013	124,997			$	31.38

	Performance share awards	37,561			26.36

	Performance shares lapsed	(34,050	)		28.03

	Performance shares forfeited	(7,027	)		32.24

	Performance shares outstanding at December 31, 2014	121,481			30.71				$	975			$	4,867

	_______________________
	(a) The unrecognized compensation expense is expected to be recognized over the weighted average remaining contractual term of the awards of approximately one year.
Schedule of Share-based Compensation, Performance Stock Activity	A summary of information related to performance shares for 2014, 2013 and 2012 is presented below:


		2014				2013				2012
	Weighted average per share grant date fair value per share of performance shares awarded	$	26.36			$	34.69			$	32.74

	Fair value of performance shares vested (in thousands)	—				849				1,193

	Intrinsic value of performance shares vested (in thousands) (a)	—				1,450				3,464

	Compensation expense (in thousands) (b)	1,181				1,188				170

	Deferred tax benefit related to compensation expense (in thousands)	413				416				59

	_____________________
	(a) Based on a 100% performance level.
	(b) Includes adjustments for forfeiture of performance share awards by certain executives.

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Income (Tables)	12 Months Ended
	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Line Items]
Schedule of Accumulated Other Comprehensive Income (Loss)

	Changes in Accumulated Other Comprehensive Income (Loss) (net of tax) by component are presented below (in thousands):
			Unrecognized Pension and Post-retirement Benefit Costs				Net Unrealized Gains (Losses) on Marketable Securities				Net Losses on Cash Flow Hedges			Accumulated Other Comprehensive Income (Loss)

	Balance at December 31, 2012		$	(75,737	)		$	22,194			$	(12,541	)	$	(66,084	)

		Other comprehensive income before reclassifications	51,371				14,482				—			65,853

		Amounts reclassified from accumulated other comprehensive income (loss)	3,036				(436		)		243			2,843

	Balance at December 31, 2013		(21,330		)		36,240				(12,298		)	2,612

		Other comprehensive income (loss) before reclassifications	(12,628		)		8,694				—			(3,934		)

		Amounts reclassified from accumulated other comprehensive income (loss)	(926		)		(5,977		)		224			(6,679		)

	Balance at December 31, 2014		$	(34,884	)		$	38,957			$	(12,074	)	$	(8,001	)


Reclassification out of Accumulated Other Comprehensive Income	Amounts reclassified from accumulated other comprehensive income (loss) for the twelve months ended December 31, 2014 and 2013 are as follows ( in thousands):


	Details about Accumulated Other Comprehensive Income (Loss) Components			2014				2013				Affected Line Item in the Statement of Operations

	Amortization of pension and post-retirement benefit costs:
		Prior service benefit		$	7,659			$	5,560			(a)

		Net loss		(6,182		)		(10,472		)		(a)
				1,477				(4,912		)		(a)

		Income tax effect		(551		)		1,876

				926				(3,036		)		(a)


	Marketable securities:
		Net realized gain on sale of securities		7,350				553				Investment and interest income, net

				7,350				553				Income before income taxes

		Income tax effect		(1,373		)		(117		)		Income tax expense
				5,977				436				Net income


	Loss on cash flow hedge:
		Amortization of loss		(438		)		(411		)		Interest on long-term debt and RCF
				(438		)		(411		)		Income before income taxes
		Income tax effect		214				168				Income tax expense

				(224		)		(243		)		Net income

		Total reclassifications		$	6,679			$	(2,843	)


	(a) These items are included in the computation of net periodic benefit cost. See Note M, Employee Benefits, for additional information.

LongTerm_Debt_and_Financing_Ob1

Long-Term Debt and Financing Obligations (Tables)	12 Months Ended
	Dec. 31, 2014
Long-Term Debt and Financing Obligations [Abstract]
Schedule of Debt	Outstanding long-term debt and financing obligations are as follows:


		December 31,
		2014			2013
		(In thousands)
	Long-Term Debt:
	Pollution Control Bonds (1):
	7.25% 2009 Series A refunding bonds, due 2040 (7.46% effective interest rate)	$	63,500		$	63,500

	4.50% 2012 Series A refunding bonds, due 2042 (4.63% effective interest rate)	59,235			59,235

	7.25% 2009 Series B refunding bonds, due 2040 (7.49% effective interest rate)	37,100			37,100

	1.875% 2012 Series A refunding bonds, due 2032 (2.35% effective interest rate)	33,300			33,300

	Total Pollution Control Bonds	193,135			193,135

	Senior Notes (2):
	6.00% Senior Notes, net of discount, due 2035 (7.12% effective interest rate)	398,021			397,976

	7.50% Senior Notes, net of discount, due 2038 (7.67% effective interest rate)	148,818			148,800

	3.30% Senior Notes, net of discount, due 2022 (3.43% effective interest rate)	149,737			149,709

	5.00% Senior Notes, net of discount, due 2044 (5.10% effective interest rate)	149,468			—

	Total Senior Notes	846,044			696,485

	RGRT Senior Notes (3):
	3.67% Senior Notes, Series A, due 2015 (3.87% effective interest rate)	15,000			15,000

	4.47% Senior Notes, Series B, due 2017 (4.62% effective interest rate)	50,000			50,000

	5.04% Senior Notes, Series C, due 2020 (5.16% effective interest rate)	45,000			45,000

	Total RGRT Senior Notes	110,000			110,000

	Total long-term debt	1,149,179			999,620

	Financing Obligations:
	Revolving Credit Facility ($14,532 due in 2015) (4)	14,532			14,352

	Total long-term debt and financing obligations	1,163,711			1,013,972

	Current Portion (amount due within one year):
	Current maturities of long term debt	(15,000		)	—

	Short-term borrowings under the revolving credit facility	(14,532		)	(14,352		)
		$	1,134,179		$	999,620

	_____________________

	-1	Pollution Control Bonds ("PCBs")

	The Company has four series of tax exempt unsecured PCBs in aggregate principal amount of $193.1 million. The 1.875% 2012 Series A (El Paso Electric Company Four Corners Project) Pollution Control Refunding Revenue Bonds with an aggregate principal amount of $33.3 million are subject to mandatory tender for purchase in September 2017.


	-2	Senior Notes

	The Senior Notes are unsecured obligations of the Company. They were issued pursuant to bond covenants that provide limitations on the Company’s ability to enter into certain transactions. The 6.00% Senior Notes have an aggregate principal amount of $400.0 million and were issued in May 2005. The proceeds, net of a $2.3 million discount, were used to fund the retirement of the Company's first mortgage bonds. The Company amortizes the loss associated with a cash flow hedge recorded in accumulated other comprehensive income to earnings as interest expense over the life of the 6.00% Senior Notes. See Note O, "Financial Instruments and Investments - Treasury Rate Locks". This amortization is included in the effective interest rate of the 6.00% Senior Notes.

	The 7.50% Senior Notes have an aggregate principal amount of $150.0 million and were issued in June 2008. The proceeds, net of a $1.3 million discount, were used to repay short-term borrowings of $44.0 million, fund capital expenditures and for other general corporate purposes.

The 3.30% Senior Notes have an aggregate principal amount of $150.0 million and were issued in December 2012. The proceeds, net of a $0.3 million discount, were used to fund construction expenditures and for working capital and general corporate purposes.

The 5.00% Senior Notes have an aggregate principal amount of $150.0 million and were issued in December 2014. The proceeds, net of a $0.5 million discount, were used to fund construction expenditures and for working capital and general corporate purposes.


-3	RGRT Senior Notes

In 2010, the Company and RGRT, a Texas grantor trust through which the Company finances its portion of fuel for Palo Verde, entered into a note purchase agreement with various institutional purchasers. Under the terms of the agreement, RGRT sold to the purchasers $110 million aggregate principal amount of Senior Notes (the "Notes") of which $15.0 million will mature in August 2015. The Company will either repay or refinance this $15.0 million of Notes upon maturity. The Company guarantees the payment of principal and interest on the Notes. In the Company’s financial statements, the assets and liabilities of the RGRT are reported as assets and liabilities of the Company.

RGRT pays interest on the Notes on February 15, and August 15 of each year until maturity. RGRT may redeem the Notes, in whole or in part, at any time at a redemption price equal to 100% of the principal amount to be redeemed together with the interest on such principal amount accrued to the date of redemption, plus a make-whole amount based on the prevailing market interest rates. The agreement requires compliance with certain covenants, including a total debt to capitalization ratio. The Company was in compliance with these requirements throughout 2014.

The sale of the Notes was made by RGRT in reliance on a private placement exemption from registration under the Securities Act of 1933, as amended. The proceeds of $109.4 million, net of issuance costs, from the sale of the Notes was used by RGRT to repay amounts borrowed under the revolving credit facility and will enable future nuclear fuel financing requirements of RGRT to be met with a combination of the Notes and amounts borrowed from the RCF.


-4	Revolving Credit Facility

On January 14, 2014, the Company and RGRT entered into a second amended and restated credit agreement related to the RCF with JP Morgan Chase Bank, N.A., as administrative agent and issuing bank, and Union Bank, N.A., as syndication agent, and various lending banks party thereto. Under the terms of the agreement, the Company has available $300 million and the ability to increase the RCF by up to $100 million (up to a total of $400 million) upon the satisfaction of certain conditions, more fully set forth in the agreement, including obtaining commitments from lenders or third party financial institutions. The RCF has a term ending January 2019. The Company may extend the maturity date up to two times, in each case for an additional one year period upon the satisfaction of certain conditions.

The RCF provides that amounts borrowed by the Company may be used for, among other things, working capital and general corporate purposes. Any amounts borrowed by RGRT may be used, among other things, to finance the acquisition and processing of nuclear fuel. Amounts borrowed by RGRT are guaranteed by the Company and the balance borrowed under the RCF is recorded as short-term borrowings on the balance sheet. The RCF is unsecured. The RCF requires compliance with certain covenants, including a total debt to capitalization ratio. The Company was in compliance with these requirements throughout 2014. As of December 31, 2014, the total amount borrowed by RGRT was $14.5 million for nuclear fuel under the RCF. As of December 31, 2014, no borrowings were outstanding under this facility for working capital and general corporate purposes. The weighted average interest rate on the RCF was 1.3% as of December 31, 2014.
Schedule of Maturities of Long-term Debt	As of December 31, 2014, the scheduled maturities for the next five years of long-term debt are as follows (in thousands):




	2015	$	15,000

	2016	—

	2017	83,300

	2018	—

	2019	—

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2014
Income Taxes [Abstract]
Schedule of Deferred Tax Assets and Liabilities	The tax effects of temporary differences that give rise to significant portions of the deferred tax assets and liabilities at December 31, 2014 and 2013 are presented below (in thousands):


		December 31,
		2014			2013
	Deferred tax assets:
	Benefit of tax loss carryforwards	$	—		$	17,709

	Alternative minimum tax credit carryforward	17,701			21,638

	Pensions and benefits	64,407			54,652

	Asset retirement obligation	25,725			23,727

	Other	15,768			14,485

	Total gross deferred tax assets	123,601			132,211

	Deferred tax liabilities:
	Plant, principally due to depreciation and basis differences	(536,264		)	(511,847		)
	Decommissioning	(40,373		)	(35,489		)
	Deferred fuel	(3,531		)	(2,171		)
	Other	(3,630		)	(5,664		)
	Total gross deferred tax liabilities	(583,798		)	(555,171		)
	Net accumulated deferred income taxes	$	(460,197	)	$	(422,960	)
Schedule of Components of Income Tax Expense (Benefit)	The Company recognized income tax expense for 2014, 2013 and 2012 as follows (in thousands):


		Years Ended December 31,
		2014			2013			2012
	Income tax expense:
	Federal:
	Current	$	(1,250	)	$	(2,877	)	$	1,487

	Deferred	38,810			45,024			43,187

	Total federal income tax	37,560			42,147			44,674

	State:
	Current	3,209			1,854			1,931

	Deferred	641			(414		)	697

	Total state income tax	3,850			1,440			2,628

	Generation (amortization) of accumulated investment tax credits	(322		)	68			(323		)

	Total income tax expense	$	41,088		$	43,655		$	46,979

Schedule of Effective Income Tax Rate Reconciliation	Income tax provisions differ from amounts computed by applying the statutory federal income tax rate of 35% to book income before federal income tax as follows (in thousands):


		Years Ended December 31,
		2014			2013			2012
	Federal income tax expense computed on income at statutory rate	$	46,381		$	46,283		$	48,239

	Difference due to:
	State taxes, net of federal benefit	1,902			936			1,708

	AEFUDC	(3,757		)	(2,149		)	(1,845		)
	Permanent tax differences	(2,921		)	(1,153		)	(604		)
	Other	(517		)	(262		)	(519		)
	Total income tax expense	$	41,088		$	43,655		$	46,979

	Effective income tax rate	31		%	33		%	34.1		%
Summary of Income Tax Contingencies	A reconciliation of the December 31, 2014, 2013 and 2012 amount of unrecognized tax benefits is as follows (in thousands):


		2014			2013			2012
	Balance at January 1	$	7,200		$	9,800		$	9,500

	Additions for tax positions related to the current year	300			600			1,600

	Reductions for tax positions related to the current year	—			—			(900		)

	Additions for tax positions of prior years	2,200			1,700			1,400

	Reductions for tax positions of prior years	(4,500		)	(4,900		)	(1,800		)
	Balance at December 31	$	5,200		$	7,200		$	9,800

Commitments_Contingencies_and_1

Commitments, Contingencies and Uncertainties (Tables)	12 Months Ended
Commitments, Contingencies and Uncertainties (Tables)	Dec. 31, 2014
Commitments and Contingencies Disclosure [Abstract]
Long-term Purchase and Sale Commitment	The Company has entered into the following significant agreements with various counterparties for forward purchases and sales of electricity:


							Commercial
							Operation
	Type of Contract		Counterparty	Quantity		Term	Date
	Power Purchase and Sale Agreement		Freeport	25	MW	December 2008 through December 2015	N/A
	Power Purchase and Sale Agreement		Freeport	100	MW	June 2006 through December 2021	N/A
	Power Purchase Agreement		Hatch Solar Energy Center I, LLC	5	MW	July 2011 through June 2036	Jul-11
	Power Purchase Agreement		NRG	20	MW	August 2011 through August 2031	Aug-11
	Power Purchase Agreement		Sun Edison 1	10	MW	June 2012 through June 2037	Jun-12
	Power Purchase Agreement		Sun Edison 2	12	MW	May 2012 through May 2037	May 2012
	Power Purchase Agreement		Macho Springs Solar, LLC	50	MW	May 2014 through April 2034	May-14
	Power Purchase Agreement		PSEG El Paso Solar Energy Center	10	MW	December 2014 through November 2044	Dec-14
Schedule of Future Minimum Rental Payments for Operating Leases	As of December 31, 2014, the Company’s minimum future rental payments for the next five years are as follows (in thousands):




	2015	$	1,386
	2015	$	1,386
	2016	838
	2016	838
	2017	623
	2017	623
	2018	512
	2018	512
	2019	516
	2019	516

Employee_Benefits_Employee_Ben

Employee Benefits Employee Benefits (Tables)	12 Months Ended
Employee Benefits Employee Benefits (Tables)	Dec. 31, 2014
Defined Benefit Plan Disclosure [Line Items]
Schedule of Amount Recognized in Accumulated Other Comprehensive Income (Loss)

	Changes in Accumulated Other Comprehensive Income (Loss) (net of tax) by component are presented below (in thousands):
				Unrecognized Pension and Post-retirement Benefit Costs				Net Unrealized Gains (Losses) on Marketable Securities				Net Losses on Cash Flow Hedges				Accumulated Other Comprehensive Income (Loss)

	Balance at December 31, 2012			$	(75,737	)		$	22,194			$	(12,541	)		$	(66,084	)
	Balance at December 31, 2012			$	(75,737	)		$	22,194			$	(12,541	)		$	(66,084	)
		Other comprehensive income before reclassifications		51,371				14,482				—				65,853
		Other comprehensive income before reclassifications		51,371				14,482				—				65,853
		Amounts reclassified from accumulated other comprehensive income (loss)		3,036				(436		)		243				2,843
				3,036				(436		)		243				2,843
	Balance at December 31, 2013			(21,330		)		36,240				(12,298		)		2,612
	Balance at December 31, 2013			(21,330		)		36,240				(12,298		)		2,612
		Other comprehensive income (loss) before reclassifications		(12,628		)		8,694				—				(3,934		)
		Other comprehensive income (loss) before reclassifications		(12,628		)		8,694				—				(3,934		)
		Amounts reclassified from accumulated other comprehensive income (loss)		(926		)		(5,977		)		224				(6,679		)
				(926		)		(5,977		)		224				(6,679		)
	Balance at December 31, 2014			$	(34,884	)		$	38,957			$	(12,074	)		$	(8,001	)
	Balance at December 31, 2014			$	(34,884	)		$	38,957			$	(12,074	)		$	(8,001	)

Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Schedule of Net Funded Status	The obligations and funded status of the plans are presented below (in thousands):


		December 31,
		2014								2013
		Retirement				Non-Qualified				Retirement				Non-Qualified
		Income				Retirement				Income				Retirement
		Plan				Plans				Plan				Plans
	Change in projected benefit obligation:
	Benefit obligation at end of prior year	$	317,815			$	25,898			$	320,846			$	27,241
	Benefit obligation at end of prior year	$	317,815			$	25,898			$	320,846			$	27,241
	Service cost	8,284				303				9,137				190
	Service cost	8,284				303				9,137				190
	Interest cost	14,001				1,041				12,742				872
	Interest cost	14,001				1,041				12,742				872
	Amendments (a)	(33,700		)		(500		)		—				—
	Amendments (a)	(33,700		)		(500		)		—				—
	Actuarial (gain) loss	50,741				3,508				(15,373		)		(533		)
	Actuarial (gain) loss	50,741				3,508				(15,373		)		(533		)
	Benefits paid	(16,008		)		(1,853		)		(9,537		)		(1,872		)
	Benefit obligation at end of year	341,133				28,397				317,815				25,898
	Benefit obligation at end of year	341,133				28,397				317,815				25,898
	Change in plan assets:
	Fair value of plan assets at end of prior year	257,831				—				220,568				—
	Fair value of plan assets at end of prior year	257,831				—				220,568				—
	Actual return on plan assets	22,116				—				31,800				—
	Actual return on plan assets	22,116				—				31,800				—
	Employer contribution	9,000				1,853				15,000				1,872
	Employer contribution	9,000				1,853				15,000				1,872
	Benefits paid	(16,008		)		(1,853		)		(9,537		)		(1,872		)
	Fair value of plan assets at end of year	272,939				—				257,831				—
	Fair value of plan assets at end of year	272,939				—				257,831				—
	Funded status at end of year	$	(68,194	)		$	(28,397	)		$	(59,984	)		$	(25,898	)
	_____________________
	(a)Amendments relate to the modification of the Company’s Retirement Plan and Excess Benefit Plan discussed above.
Schedule of Amounts Recognized in Balance Sheet	Amounts recognized in the Company's balance sheets consist of the following (in thousands):


		December 31,
		2014								2013
		Retirement				Non-Qualified				Retirement				Non-Qualified
		Income				Retirement				Income				Retirement
		Plan				Plans				Plan				Plans
	Current liabilities	$	—			$	(2,319	)		$	—			$	(1,870	)
	Current liabilities	$	—			$	(2,319	)		$	—			$	(1,870	)
	Noncurrent liabilities	(68,194		)		(26,078		)		(59,984		)		(24,028		)
	Total	$	(68,194	)		$	(28,397	)		$	(59,984	)		$	(25,898	)
Schedule of Accumulated Benefit Obligations in Excess of Fair Value of Plan Assets	The accumulated benefit obligation in excess of plan assets is as follows (in thousands):


		December 31,
		2014								2013
		Retirement				Non-Qualified				Retirement				Non-Qualified
		Income				Retirement				Income				Retirement
		Plan				Plans				Plan				Plans
	Projected benefit obligation	$	(341,133	)		$	(28,397	)		$	(317,815	)		$	(25,898	)
	Accumulated benefit obligation	(312,762		)		(27,603		)		(275,555		)		(25,077		)
	Fair value of plan assets	272,939				—				257,831				—
	Fair value of plan assets	272,939				—				257,831				—
Schedule of Amounts Recognized in Accumulated Other Comprehensive Income (Loss)	Amounts recognized in accumulated other comprehensive income consist of the following (in thousands):


		Years Ended December 31,
		2014								2013
		Retirement				Non-Qualified				Retirement				Non-Qualified
		Income				Retirement				Income				Retirement
		Plan				Plans				Plan				Plans
	Net loss	$	124,407			$	11,341			$	85,261			$	8,508
	Net loss	$	124,407			$	11,341			$	85,261			$	8,508
	Prior service cost (benefit)	(30,811		)		(264		)		—				219
	Prior service cost (benefit)	(30,811		)		(264		)		—				219
	Total	$	93,596			$	11,077			$	85,261			$	8,727
	Total	$	93,596			$	11,077			$	85,261			$	8,727
Schedule of Net Periodic Benefit Costs	The components of net periodic benefit cost are presented below (in thousands):


		Years Ended December 31,
		2014								2013								2012
		Retirement				Non-Qualified				Retirement				Non-Qualified				Retirement				Non-Qualified
		Income				Retirement				Income				Retirement				Income				Retirement
		Plan				Plans				Plan				Plans				Plan				Plans
	Service cost	$	8,284			$	303			$	9,137			$	190			$	8,530			$	299
	Service cost	$	8,284			$	303			$	9,137			$	190			$	8,530			$	299
	Interest cost	14,001				1,041				12,742				872				12,594				963
	Interest cost	14,001				1,041				12,742				872				12,594				963
	Expected return on plan assets	(18,699		)		—				(17,108		)		—				(14,443		)		—
	Expected return on plan assets	(18,699		)		—				(17,108		)		—				(14,443		)		—
	Amortization of:
	Net loss	8,178				675				10,437				661				10,729				627
	Net loss	8,178				675				10,437				661				10,729				627
	Prior service cost (benefit)	(2,889		)		(17		)		3				94				21				94
	Prior service cost (benefit)	(2,889		)		(17		)		3				94				21				94
	Net periodic benefit cost	$	8,875			$	2,002			$	15,211			$	1,817			$	17,431			$	1,983
	Net periodic benefit cost	$	8,875			$	2,002			$	15,211			$	1,817			$	17,431			$	1,983
Schedule of Defined Benefit Plan Amounts Recognized in Other Comprehensive Income (Loss)	The changes in benefit obligations recognized in other comprehensive income are presented below (in thousands):


		Years Ended December 31,
		2014								2013								2012
		Retirement				Non-Qualified				Retirement				Non-Qualified				Retirement				Non-Qualified
		Income				Retirement				Income				Retirement				Income				Retirement
		Plan				Plans				Plan				Plans				Plan				Plans
	Net (gain) loss	$	47,324			$	3,508			$	(30,065	)		$	(533	)		$	6,672			$	1,337
	Net (gain) loss	$	47,324			$	3,508			$	(30,065	)		$	(533	)		$	6,672			$	1,337
	Prior service benefit	(33,700		)		(500		)		—				—				—				—
	Prior service benefit	(33,700		)		(500		)		—				—				—				—
	Amortization of:
	Net loss	(8,178		)		(675		)		(10,437		)		(661		)		(10,729		)		(627		)
	Prior service (cost) benefit	2,889				17				(3		)		(94		)		(21		)		(94		)
	Prior service (cost) benefit	2,889				17				(3		)		(94		)		(21		)		(94		)
	Total recognized in other comprehensive income	$	8,335			$	2,350			$	(40,505	)		$	(1,288	)		$	(4,078	)		$	616
	Total recognized in other comprehensive income	$	8,335			$	2,350			$	(40,505	)		$	(1,288	)		$	(4,078	)		$	616
Schedule of Recognized Net Periodic Benefit Obligation and Other Comprehensive Income	The total amount recognized in net periodic benefit costs and other comprehensive income are presented below (in thousands):


		Years Ended December 31,
		2014								2013								2012
		Retirement				Non-Qualified				Retirement				Non-Qualified				Retirement				Non-Qualified
		Income				Retirement				Income				Retirement				Income				Retirement
		Plan				Plans				Plan				Plans				Plan				Plans
	Total recognized in net periodic benefit cost and other comprehensive income	$	17,210			$	4,352			$	(25,294	)		$	529			$	13,353			$	2,599
		$	17,210			$	4,352			$	(25,294	)		$	529			$	13,353			$	2,599
Schedule of Amounts in Accumulated Other Comprehensive Income (Loss) to be Recognized over Next Fiscal Year	The following are amounts in accumulated other comprehensive income that are expected to be recognized as components of net periodic benefit cost during 2015 (in thousands):


		Retirement				Non-Qualified
		Income				Retirement
		Plan				Plans
	Net loss	$	10,220			$	850
	Net loss	$	10,220			$	850
	Prior service benefit	(3,470		)		(40		)
Schedule of Expected Benefit Payments	The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid (in thousands):



		Retirement				Non-Qualified
		Income				Retirement
		Plan				Plans
	2015	$	15,776			$	2,319
	2015	$	15,776			$	2,319
	2016	17,153				2,248
	2016	17,153				2,248
	2017	17,778				2,171
	2017	17,778				2,171
	2018	20,019				2,196
	2018	20,019				2,196
	2019	19,500				2,135
	2019	19,500				2,135
	2020-2024	103,703				10,720
	2020-2024	103,703				10,720
Retirement Plans \| Net Periodic Benefit Costs
Defined Benefit Plan Disclosure [Line Items]
Schedule of Assumptions Used	The following are the weighted-average actuarial assumptions used to determine the net periodic benefit cost for the twelve months ended December 31:


		2014 (a)									2013									2012
					Non-Qualified									Non-Qualified									Non-Qualified
		Retirement			Supplemental Retirement			Excess			Retirement			Supplemental Retirement			Excess			Retirement			Supplemental Retirement		Excess
		Income			Plan			Benefit			Income			Plan			Benefit			Income			Plan		Benefit
		Plan						Plan			Plan						Plan			Plan					Plan
	Discount rate	4.9	%		3.9	%		4.9	%		4	%		3.1	%		4	%		4.3	%		3.6	%	4.1	%
	Expected long-term return on plan assets	7.5	%		N/A			N/A			7.5	%		N/A			N/A			7.5	%		N/A		N/A
	Expected long-term return on plan assets	7.5	%		N/A			N/A			7.5	%		N/A			N/A			7.5	%		N/A		N/A
	Rate of compensation increase	4.75	%		N/A			4.75	%		4.75	%		N/A			4.75	%		5	%		N/A		5	%
	Rate of compensation increase	4.75	%		N/A			4.75	%		4.75	%		N/A			4.75	%		5	%		N/A		5	%
	_____________________

	(a)	The Retirement Plan and the Excess Benefit Plan were remeasured on February 28, 2014 due to the above mentioned plan amendment. The discount rate used to remeasure the benefit obligation was 4.6% for the Retirement Plan and 4.5% for the Excess Benefit Plan, compared to 4.9% for both plans as of January 1, 2014. All other assumptions remained consistent with assumptions used at January 1, 2014.
Retirement Plans \| Benefit Obligations
Defined Benefit Plan Disclosure [Line Items]
Schedule of Assumptions Used	The following are the weighted-average actuarial assumptions used to determine the benefit obligations:


		December 31,
		2014									2013
					Non-Qualified									Non-Qualified
		Retirement			Supplemental			Excess			Retirement			Supplemental			Excess
		Income			Retirement			Benefit			Income			Retirement			Benefit
		Plan			Plan			Plan			Plan			Plan			Plan
	Discount rate	4	%		3.4	%		4.1	%		4.9	%		3.9	%		4.9	%
	Rate of compensation increase	4.5	%		N/A			4.5	%		4.75	%		N/A			4.75	%
	Rate of compensation increase	4.5	%		N/A			4.5	%		4.75	%		N/A			4.75	%
Retirement Income Plan
Defined Benefit Plan Disclosure [Line Items]
Schedule of Allocation of Plan Assets	The expected long-term rate of return is based on the weighted average of the expected returns on investments based upon the target asset allocation of the pension fund. The Company’s target allocations for the plan’s assets are presented below:


			December 31, 2014
	Equity securities		55	%
	Fixed income		40	%
	Alternative investments		5	%
	Total		100	%
Fair Value, Measurement Inputs, Disclosure	The fair value of the Company’s Retirement Plan assets at December 31, 2014 and 2013, and the level within the three levels of the fair value hierarchy defined by FASB guidance on fair value measurements are presented in the table below (in thousands):


	Description of Securities	Fair Value as of				Quoted Prices				Significant				Significant
		December 31,				in Active				Other				Unobservable
		2014				Markets for				Observable				Inputs
						Identical Assets				Inputs				(Level 3)
						(Level 1)				(Level 2)
	Cash and Cash Equivalents	$	1,237			$	1,237			$	—			$	—
	Cash and Cash Equivalents	$	1,237			$	1,237			$	—			$	—
	Common Collective Trusts (a)
	Equity funds	149,839				—				149,839				—
	Equity funds	149,839				—				149,839				—
	Fixed income funds	113,115				—				113,115				—
	Fixed income funds	113,115				—				113,115				—
	Total Common Collective Trusts	262,954				—				262,954				—
	Total Common Collective Trusts	262,954				—				262,954				—
	Limited Partnership Interest in Real Estate (b)	8,748				—				—				8,748
	Limited Partnership Interest in Real Estate (b)	8,748				—				—				8,748
	Total Plan Investments	$	272,939			$	1,237			$	262,954			$	8,748
	Total Plan Investments	$	272,939			$	1,237			$	262,954			$	8,748



	Description of Securities	Fair Value as of				Quoted Prices				Significant				Significant
		December 31,				in Active				Other				Unobservable
		2013				Markets for				Observable				Inputs
						Identical Assets				Inputs				(Level 3)
						(Level 1)				(Level 2)
	Cash and Cash Equivalents	$	940			$	940			$	—			$	—
	Cash and Cash Equivalents	$	940			$	940			$	—			$	—
	Guaranteed Investment Contract	1,126				—				1,126				—
	Guaranteed Investment Contract	1,126				—				1,126				—
	Common Collective Trust (a)
	Equity funds	142,960				—				142,960				—
	Equity funds	142,960				—				142,960				—
	Fixed income funds	103,948				—				103,948				—
	Fixed income funds	103,948				—				103,948				—
	Total Common Collective Trusts	246,908				—				246,908				—
	Total Common Collective Trusts	246,908				—				246,908				—
	Limited Partnership Interest in Real Estate (b)	8,857				—				—				8,857
	Limited Partnership Interest in Real Estate (b)	8,857				—				—				8,857
	Total Plan Investments	$	257,831			$	940			$	248,034			$	8,857
	Total Plan Investments	$	257,831			$	940			$	248,034			$	8,857
	_____________________

	(a)	The Common Collective Trusts are invested in equity or fixed income securities, or a combination thereof. The investment objective of each trust is to produce returns in excess of, or commensurate with, its predefined index.

	(b)	This investment is a commercial real estate partnership that purchases land, develops limited infrastructure, and sells it for commercial development. The Company is restricted from selling its partnership interest during the life of the partnership which is generally 5-7 years. Return on investment is realized as land is sold. The fair value of the limited partnership interest in real estate is based on the NAV of the partnership which reflects the appraised value of the land.
Changes in Fair Value of Investments in Real Estate	The table below reflects the changes in the fair value of investments in real estate during the period (in thousands):



		Fair Value of
		Investments in
		Real Estate
	Balances at December 31, 2012	$	8,559
	Balances at December 31, 2012	$	8,559
	Unrealized gain in fair value	298
	Unrealized gain in fair value	298
	Balances at December 31, 2013	8,857
	Balances at December 31, 2013	8,857
	Sale of land	(357		)
	Unrealized gain in fair value	248
	Unrealized gain in fair value	248
	Balances at December 31, 2014	$	8,748
	Balances at December 31, 2014	$	8,748
Other Postretirement Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Schedule of Net Funded Status	The following table contains a reconciliation of the change in the benefit obligation, the fair value of plan assets, and the funded status of the plan (in thousands):


		December 31,
		2014				2013
	Change in benefit obligation:
	Benefit obligation at end of prior year	$	92,847			$	135,680
	Benefit obligation at end of prior year	$	92,847			$	135,680
	Service cost	2,845				3,843
	Service cost	2,845				3,843
	Interest cost	4,463				5,156
	Interest cost	4,463				5,156
	Actuarial loss (gain)	3,465				(48,778		)
	Actuarial loss (gain)	3,465				(48,778		)
	Amendment (a)	—				(97		)
	Amendment (a)	—				(97		)
	Benefits paid	(4,031		)		(4,013		)
	Retiree contributions	1,111				1,056
	Retiree contributions	1,111				1,056
	Benefit obligation at end of year	100,700				92,847
	Benefit obligation at end of year	100,700				92,847
	Change in plan assets:
	Fair value of plan assets at end of prior year	42,192				36,510
	Fair value of plan assets at end of prior year	42,192				36,510
	Actual return on plan assets	2,086				5,539
	Actual return on plan assets	2,086				5,539
	Employer contribution	—				3,100
	Employer contribution	—				3,100
	Benefits paid	(4,031		)		(4,013		)
	Retiree contributions	1,111				1,056
	Retiree contributions	1,111				1,056
	Fair value of plan assets at end of year	41,358				42,192
	Fair value of plan assets at end of year	41,358				42,192
	Funded status at end of year	$	(59,342	)		$	(50,655	)
	_____________________

	(a)	Amendment relates to modification of the Company's Other Post-retirement Benefit Plan which limits the Company's premium contribution. The amendment became effective October 3, 2013 and resulted in a remeasurement of the plan.
Schedule of Amounts Recognized in Balance Sheet	Amounts recognized in the Company's balance sheets consist of the following (in thousands):


		December 31,
		2014				2013
	Current liabilities	$	—			$	—
	Current liabilities	$	—			$	—
	Noncurrent liabilities	(59,342		)		(50,655		)
	Total	$	(59,342	)		$	(50,655	)
Schedule of Net Periodic Benefit Costs	Net periodic benefit cost is made up of the components listed below (in thousands):


		Years Ended December 31,
		2014				2013				2012
	Service cost	$	2,845			$	3,843			$	4,378
	Service cost	$	2,845			$	3,843			$	4,378
	Interest cost	4,463				5,156				5,651
	Interest cost	4,463				5,156				5,651
	Expected return on plan assets	(2,116		)		(1,951		)		(1,714		)
	Amortization of:
	Prior service benefit	(4,753		)		(5,657		)		(5,877		)
	Net (gain) loss	(2,671		)		(626		)		615
	Net (gain) loss	(2,671		)		(626		)		615
	Net periodic benefit cost	$	(2,232	)		$	765			$	3,053
	Net periodic benefit cost	$	(2,232	)		$	765			$	3,053
Schedule of Defined Benefit Plan Amounts Recognized in Other Comprehensive Income (Loss)	The changes in benefit obligations recognized in other comprehensive income are presented below (in thousands):


		Years Ended December 31,
		2014				2013				2012
	Net (gain) loss	$	3,496			$	(52,366	)		$	(5,900	)
	Net (gain) loss	$	3,496			$	(52,366	)		$	(5,900	)
	Prior service benefit	—				(97		)		—
	Prior service benefit	—				(97		)		—
	Amortization of:
	Prior service benefit	4,753				5,657				5,877
	Prior service benefit	4,753				5,657				5,877
	Net gain (loss)	2,671				626				(615		)
	Net gain (loss)	2,671				626				(615		)
	Total recognized in other comprehensive income	$	10,920			$	(46,180	)		$	(638	)
	Total recognized in other comprehensive income	$	10,920			$	(46,180	)		$	(638	)
Schedule of Recognized Net Periodic Benefit Obligation and Other Comprehensive Income	The total amount recognized in net periodic benefit cost and other comprehensive income are presented below (in thousands):


		Years Ended December 31,
		2014				2013				2012
	Total recognized in net periodic benefit cost and other comprehensive income	$	8,688			$	(45,415	)		$	2,415
		$	8,688			$	(45,415	)		$	2,415
Schedule of Allocation of Plan Assets	The Company’s target allocations for the plan’s assets are presented below:


			December 31, 2014
	Equity securities		65	%
	Fixed income		30	%
	Alternative investments		5	%
	Total		100	%
Fair Value, Measurement Inputs, Disclosure	The fair value of the Company’s Other Post-retirement Benefits Plan assets at December 31, 2014 and 2013, and the level within the three levels of the fair value hierarchy defined by FASB guidance on fair value measurements are presented in the table below (in thousands):


	Description of Securities	Fair Value as of				Quoted Prices				Significant				Significant
		December 31,				in Active				Other				Unobservable
		2014				Markets for				Observable				Inputs
						Identical Assets				Inputs				(Level 3)
						(Level 1)				(Level 2)
	Cash and Cash Equivalents	$	1,100			$	1,100			$	—			$	—
	Cash and Cash Equivalents	$	1,100			$	1,100			$	—			$	—
	Common Collective Trusts (a)
	Equity funds	26,399				—				26,399				—
	Equity funds	26,399				—				26,399				—
	Fixed income funds	12,219				—				12,219				—
	Fixed income funds	12,219				—				12,219				—
	Total Common Collective Trusts	38,618				—				38,618				—
	Total Common Collective Trusts	38,618				—				38,618				—
	Limited Partnership Interest in Real Estate (b)	1,640				—				—				1,640
	Limited Partnership Interest in Real Estate (b)	1,640				—				—				1,640
	Total Plan Investments	$	41,358			$	1,100			$	38,618			$	1,640
	Total Plan Investments	$	41,358			$	1,100			$	38,618			$	1,640

	Description of Securities	Fair Value as of				Quoted Prices				Significant				Significant
		December 31,				in Active				Other				Unobservable
		2013				Markets for				Observable				Inputs
						Identical Assets				Inputs				(Level 3)
						(Level 1)				(Level 2)
	Cash and Cash Equivalents	$	33			$	33			$	—			$	—
	Cash and Cash Equivalents	$	33			$	33			$	—			$	—
	Common Collective Trust (a)
	Equity funds	28,077				—				28,077				—
	Equity funds	28,077				—				28,077				—
	Fixed income funds	12,421				—				12,421				—
	Fixed income funds	12,421				—				12,421				—
	Total Common Collective Trusts	40,498				—				40,498				—
	Total Common Collective Trusts	40,498				—				40,498				—
	Limited Partnership Interest in Real Estate (b)	1,661				—				—				1,661
	Limited Partnership Interest in Real Estate (b)	1,661				—				—				1,661
	Total Plan Investments	$	42,192			$	33			$	40,498			$	1,661
	Total Plan Investments	$	42,192			$	33			$	40,498			$	1,661
	___________________

	(a)	The Common Collective Trusts are invested in equity or fixed income securities, or a combination thereof. The investment objective of each trust is to produce returns in excess of, or commensurate with, its predefined index.

	(b)	This investment is a commercial real estate partnership that purchases land, develops limited infrastructure, and sells it for commercial development. The Company is restricted from selling its partnership interest during the life of the partnership which is generally 5-7 years. Return of investment is realized as land is sold. The fair value of the limited partnership interest in real estate is based on the NAV of the partnership which reflects the appraised value of the land.
Changes in Fair Value of Investments in Real Estate	The table below reflects the changes in the fair value of the investments in real estate during the period (in thousands):



		Fair Value of
		Investments in
		Real Estate
	Balance at December 31, 2012	$	1,605
	Balance at December 31, 2012	$	1,605
	Unrealized gain in fair value	56
	Unrealized gain in fair value	56
	Balance at December 31, 2013	1,661
	Balance at December 31, 2013	1,661
	Sale of land	(67		)
	Unrealized gain in fair value	46
	Unrealized gain in fair value	46
	Balance at December 31, 2014	$	1,640
	Balance at December 31, 2014	$	1,640
Schedule of Expected Benefit Payments	The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid (in thousands):



	2015	$	3,163
	2015	$	3,163
	2016	3,528
	2016	3,528
	2017	3,906
	2017	3,906
	2018	4,303
	2018	4,303
	2019	4,570
	2019	4,570
	2020-2024	27,362
	2020-2024	27,362
Schedule of Amount Recognized in Accumulated Other Comprehensive Income (Loss)	Amounts recognized in accumulated other comprehensive income consist of the following (in thousands):



		December 31,
		2014				2013
	Net gain	$	(31,943	)		$	(38,110	)
	Prior service benefit	(14,457		)		(19,210		)
	Total	$	(46,400	)		$	(57,320	)
Other Postretirement Benefit Plan \| Net Periodic Benefit Costs
Defined Benefit Plan Disclosure [Line Items]
Schedule of Assumptions Used	The following are the weighted-average actuarial assumptions used to determine the net periodic benefit cost for the twelve months ended December 31:


		2014			2013 (a)			2012
	Discount rate at beginning of year	4.9	%		4.1	%		4.3	%
	Expected long-term return on plan assets	5.2	%		5.2	%		5.2	%
	Health care cost trend rates:
	Initial	7.5	%		7.75	%		8	%
	Ultimate	4.5	%		4.5	%		4.5	%
	Year ultimate reached	2026			2026			2026
	Year ultimate reached	2026			2026			2026
	_____________________
	(a) The Other Post-retirement Benefits Plan was remeasured at October 3, 2013 due to a plan amendment. The discount rate increased from 4.1% as of January 1, 2013 to 4.9% at the remeasurement date. All other assumptions remained consistent with assumptions used at January 1, 2013.
Other Postretirement Benefit Plan \| Accrued Postretirement Benefit
Defined Benefit Plan Disclosure [Line Items]
Schedule of Assumptions Used	The following are the weighted-average actuarial assumptions used to determine the accrued post-retirement benefit obligations:



		December 31,
		2014			2013
	Discount rate at end of year	4.1	%		4.9	%
	Health care cost trend rates:
	Initial	7.25	%		7.5	%
	Ultimate	4.5	%		4.5	%
	Year ultimate reached	2026			2026
	Year ultimate reached	2026			2026

Franchises_and_Significant_Cus1

Franchises and Significant Customers Franchises and Significant Customers (Tables)	12 Months Ended
	Dec. 31, 2014
Franchises and Significant Customers [Abstract]
Schedule of Franchise Fee Agreements	The franchise arrangements held between the Company and the cities of El Paso and Las Cruces are detailed below:


	City	Period	Franchise Fee	(a)
	El Paso	August 1, 2010 - Present	4.00%	(b)
	Las Cruces	February 1, 2000 - Present	2.00%
	_________________
	(a) Based on a percentage of revenue.
	(b) 0.75% of the El Paso franchise fee is to be placed in a restricted fund to be used solely for economic development and renewable energy purposes.

Recovered_Sheet1

Financial Instruments And Investments (Tables)	12 Months Ended
	Dec. 31, 2014
Fair Value Disclosures [Abstract]
Fair Values Of Long-Term Debt And Short-Term Borrowings Under the RCF	Long-Term Debt and Short-Term Borrowings Under the RCF. The fair values of the Company's long-term debt and short-term borrowings under the RCF are based on estimated market prices for similar issues and are presented below (in thousands):


		December 31,
		2014								2013
		Carrying				Estimated				Carrying				Estimated
		Amount				Fair Value				Amount				Fair Value
	Pollution Control Bonds	$	193,135			$	213,083			$	193,135			$	193,990

	Senior Notes	846,044				968,728				696,485				734,515

	RGRT Senior Notes (1)	110,000				117,215				110,000				115,850

	RCF (1)	14,532				14,532				14,352				14,352

	Total	$	1,163,711			$	1,313,558			$	1,013,972			$	1,058,707

	__________________

	-1	Nuclear fuel financing as of December 31, 2014 and December 31, 2013 is funded through the $110 million RGRT Senior Notes and $14.5 million and $14.4 million, respectively under the RCF. As of December 31, 2014 and 2013, no amount was outstanding under the RCF for working capital or general corporate purposes. The interest rate on the Company’s borrowings under the RCF is reset throughout the period reflecting current market rates. Consequently, the carrying value approximates fair value.
Unrecognized Gross Unrealized Gains (Losses) And the Fair Value	The tables below present the gross unrealized losses and the fair value of these securities, aggregated by investment category and length of time that individual securities have been in a continuous unrealized loss position (in thousands):



		December 31, 2014
		Less than 12 Months								12 Months or Longer							Total
		Fair				Unrealized				Fair				Unrealized			Fair		Unrealized
		Value				Losses				Value				Losses			Value		Losses
	Description of Securities (1):
	Federal Agency Mortgage Backed Securities	$	—			$	—			$	2,383			$	(57	)	$	2,383	$	(57	)

	U.S. Government Bonds	1,552				(2		)		20,060				(573		)	21,612		(575		)

	Municipal Obligations	6,433				(65		)		8,570				(410		)	15,003		(475		)

	Corporate Obligations	2,455				(24		)		2,461				(111		)	4,916		(135		)

	Total Debt Securities	10,440				(91		)		33,474				(1,151		)	43,914		(1,242		)

	Common Stock	1,475				(229		)		—				—			1,475		(229		)

	Common Collective Trust-Equity Funds	22,736				(821		)		—				—			22,736		(821		)

	Total Temporarily Impaired Securities	$	34,651			$	(1,141	)		$	33,474			$	(1,151	)	$	68,125	$	(2,292	)

	____________________

	-1	Includes approximately 106 securities.


		December 31, 2013
		Less than 12 Months								12 Months or Longer							Total
		Fair				Unrealized				Fair				Unrealized			Fair		Unrealized
		Value				Losses				Value				Losses			Value		Losses
	Description of Securities (2):
	Federal Agency Mortgage Backed Securities	$	6,444			$	(169	)		$	1,421			$	(119	)	$	7,865	$	(288	)

	U.S. Government Bonds	8,114				(245		)		10,866				(840		)	18,980		(1,085		)

	Municipal Obligations	12,286				(335		)		7,782				(479		)	20,068		(814		)

	Corporate Obligations	3,284				(96		)		901				(54		)	4,185		(150		)

	Total Debt Securities	30,128				(845		)		20,970				(1,492		)	51,098		(2,337		)

	Common stock	2,305				(126		)		—				—			2,305		(126		)

	Total Temporarily Impaired Securities	$	32,433			$	(971	)		$	20,970			$	(1,492	)	$	53,403	$	(2,463	)

	______________________

	-2	Includes approximately 122 securities.
	The Company monitors the length of time the security trades below its cost basis along with the amount and percentage of the unrealized loss in determining if a decline in fair value of marketable securities below recorded cost is considered to be other than temporary. In addition, the Company will research the future prospects of individual securities as necessary. As a result of these factors, as well as the Company’s intent and ability to hold these securities until their market price recovers, these securities are considered temporarily impaired. The Company does not anticipate expending monies held in trust before 2044 or a later period when the Company begins to decommission Palo Verde.








	The reported fair values also include gross unrealized gains on marketable securities which have not been recognized in the Company’s net income. The table below presents the unrecognized gross unrealized gains and the fair value of these securities, aggregated by investment category (in thousands):



	December 31, 2014								December 31, 2013
	Fair				Unrealized				Fair				Unrealized
	Value				Gains				Value				Gains
Description of Securities:
Federal Agency Mortgage Backed Securities	$	15,388			$	665			$	9,929			$	433

U.S. Government Bonds	20,016				567				6,258				126

Municipal Obligations	11,642				595				8,783				450

Corporate Obligations	13,762				850				9,188				506

Total Debt Securities	60,808				2,677				34,158				1,515

Common Stock	99,160				48,253				103,808				43,145

Equity Mutual Funds	—				—				16,802				3,081

Cash and Cash Equivalents	6,193				—				5,924				—

Total	$	166,161			$	50,930			$	160,692			$	47,741

Contractual Year For Maturity Of Available-For-Sale Securities	The contractual year for maturity for these available-for-sale securities as of December 31, 2014 is as follows (in thousands):


		Total				2015				2016				2020 through 2024			2025 and Beyond
										through
										2019
	Municipal Debt Obligations	$	26,645			$	1,011			$	11,318			$	12,967		$	1,349

	Corporate Debt Obligations	18,678				720				5,163				6,517			6,278

	U.S. Government Bonds	41,628				3,050				17,520				12,062			8,996

Unrealized Holding Losses Included In Pre-Tax Income	For the twelve months ended December 31, 2014, 2013, and 2012 the Company recognized other than temporary impairment losses on its available-for-sale securities as follows (in thousands):


		2014				2013				2012
	Unrealized holding losses included in pre-tax income	$	—			$	—			$	(479	)

Sale of Securities And The Related Effects On Pre-Tax Income	The proceeds from the sale of these securities during the twelve months ended December 31, 2014, 2013, and 2012 and the related effects on pre-tax income are as follows (in thousands):


		2014				2013				2012
	Proceeds from sales or maturities of available-for-sale securities	$	108,311			$	56,148			$	98,542

	Gross realized gains included in pre-tax income	$	7,858			$	986			$	1,478

	Gross realized losses included in pre-tax income	(508		)		(433		)		(2,041		)
	Gross unrealized losses included in pre-tax income	—				—				(479		)

	Net gains (losses) in pre-tax income	$	7,350			$	553			$	(1,042	)

	Net unrealized holding gains included in accumulated other comprehensive income	$	10,827			$	17,699			$	9,927

	Net (gains) losses reclassified out of accumulated other comprehensive income	(7,350		)		(553		)		1,042

	Net gains in other comprehensive income	$	3,477			$	17,146			$	10,969

Fair Value, Measurement Inputs, Disclosure	The fair value of the Company’s decommissioning trust funds and investments in debt securities, at December 31, 2014 and 2013, and the level within the three levels of the fair value hierarchy defined by FASB guidance are presented in the table below (in thousands):


	Description of Securities		Fair Value as of				Quoted Prices				Significant				Significant
			December 31,				in Active				Other				Unobservable
			2014				Markets for				Observable				Inputs
							Identical Assets				Inputs				(Level 3)
							(Level 1)				(Level 2)
	Trading Securities:
	Investments in Debt Securities		$	1,653			$	—			$	—			$	1,653

	Available for sale:
	U.S. Government Bonds		$	41,628			$	41,628			$	—			$	—

	Federal Agency Mortgage Backed Securities		17,771				—				17,771				—

	Municipal Obligations		26,645				—				26,645				—

	Corporate Obligations		18,678				—				18,678				—

	Subtotal, Debt Securities		104,722				41,628				63,094				—

	Common Stock		100,635				100,635				—				—

	Common Collective Trust-Equity Funds		22,736				—				22,736				—

	Cash and Cash Equivalents		6,193				6,193				—				—

	Total available for sale		$	234,286			$	148,456			$	85,830			$	—




	Description of Securities	Fair Value as of				Quoted Prices				Significant				Significant
		December 31,				in Active				Other				Unobservable
		2013				Markets for				Observable				Inputs
						Identical Assets				Inputs				(Level 3)
						(Level 1)				(Level 2)
	Trading Securities:
	Investments in Debt Securities	$	1,555			$	—			$	—			$	1,555

	Available for sale:
	U.S. Government Bonds	$	25,238			$	25,238			$	—			$	—

	Federal Agency Mortgage Backed Securities	17,794				—				17,794				—

	Municipal Obligations	28,851				—				28,851				—

	Corporate Obligations	13,373				—				13,373				—

	Subtotal, Debt Securities	85,256				25,238				60,018				—

	Common Stock	106,113				106,113				—				—

	Equity Mutual Funds	16,802				16,802				—				—

	Cash and Cash Equivalents	5,924				5,924				—				—

	Total available for sale	$	214,095			$	154,077			$	60,018			$	—

Trading Securities (and Certain Trading Assets)	Below is a reconciliation of the beginning and ending balance of the fair value of the investment in debt securities (in thousands):


		2014				2013
	Balance at January 1	$	1,555			$	1,295

	Net unrealized gains in fair value recognized in income (a)	98				260

	Balance at December 31	$	1,653			$	1,555

	_____________________
	(a) These amounts are reflected in the Company's statement of operations as investment and interest income.

Supplemental_Statements_of_Cas1

Supplemental Statements of Cash Flows Disclosures Supplemental Statements of Cash Flows Disclosures (Tables)	12 Months Ended
	Dec. 31, 2014
Supplemental Cash Flow Information [Abstract]
Schedule of Cash Flow, Supplemental Disclosures

		Years Ended December 31,
		2014		2013		2012
		(In thousands)
	Cash paid for:
	Interest on long-term debt and borrowing under the revolving credit facility	$	54,792	$	53,752	$	50,189

	Income taxes, net of refund	6,876		244		5,031

	Non-cash financing activities:
	Grants of restricted shares of common stock	3,025		3,224		2,411

	Issuance of performance shares	—		849		1,193

Selected_Quarterly_Financial_D1

Selected Quarterly Financial Data (Unaudited) Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2014
Quarterly Financial Information Disclosure [Abstract]
Schedule of Quarterly Financial Information	The quarterly earnings per share amounts for a year will not add to the earnings per share for that year due to the weighting of shares used in calculating per share data.



		2014 Quarters								2013 Quarters
		4th		3rd		2nd		1st		4th		3rd		2nd		1st
						(In thousands except for share data)
	Operating revenues (1)	$	196,563	$	283,645	$	251,801	$	185,516	$	190,297	$	282,661	$	240,114	$	177,290

	Operating income	8,871		81,496		51,131		9,665		6,050		85,896		54,344		19,345

	Net income	4,241		52,476		30,096		4,615		1,191		50,565		29,193		7,634

	Basic earnings per share:
	Net income	0.1		1.3		0.75		0.11		0.03		1.26		0.73		0.19

	Diluted earnings per share:
	Net income	0.1		1.3		0.75		0.11		0.03		1.26		0.72		0.19

	Dividends declared per share of common stock	0.28		0.28		0.28		0.265		0.265		0.265		0.265		0.25

	________________

	-1	Operating revenues are seasonal in nature, with the peak sales periods generally occurring during the summer months. Comparisons among quarters of a year may not represent overall trends and changes in operations.

Summary_of_Significant_Account3

Summary of Significant Accounting Policies (General) (Details)	Dec. 31, 2014
	sqmi
General [Abstract]
Area of Services, in Square Miles	10,000

Summary_of_Significant_Account4

Summary of Significant Accounting Policies (Utility Plant) (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Significant Accounting Policies [Line Items]
Average composite depreciation rate	2.60%	2.61%	2.64%
AFUDC rate	8.15%	8.10%	8.53%
Minimum
Significant Accounting Policies [Line Items]
Public Utilities Property, Plant and Equipment, Useful Life	5 years
Maximum
Significant Accounting Policies [Line Items]
Public Utilities Property, Plant and Equipment, Useful Life	48 years

Summary_of_Significant_Account5

Summary of Significant Accounting Policies (Revenues) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Accounting Policies [Abstract]
Accrued unbilled revenues	$21.20	$19.80

Summary_of_Significant_Account6

Summary of Significant Accounting Policies (Allowance For Doubtful Accounts) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Accounts Receivable, Net [Abstract]
Balance at beginning of year	$2,261	$2,906	$3,015
Additions:
Charged to costs and expense	2,755	2,098	3,087
Recovery of previous write-offs	1,516	1,929	2,041
Uncollectible receivables written off	4,279	4,672	5,237
Balance at end of year	$2,253	$2,261	$2,906

Regulation_Narrative_Details

Regulation (Narrative) (Details) (USD $)

12 Months Ended

0 Months Ended

3 Months Ended

0 Months Ended

12 Months Ended

45 Months Ended

48 Months Ended

0 Months Ended

Dec. 31, 2014

1-May-14

Dec. 31, 2014

Jul. 11, 2014

28-May-14

Feb. 28, 2015

Mar. 31, 2013

Dec. 31, 2012

Mar. 10, 2014

Aug. 18, 2014

Dec. 31, 2013

Jan. 31, 2013

Under-collection of fuel revenues

$10,253,000

$7,248,000

Number of Presidential Permit(s)

Contract Termination Provision, Period

2 years

PUCT

Public Utilities Requested Performance Incentive Bonus Related To Energy Efficiency Program

2,000,000

Fuel Over And Under Materiality Threshold Percentage

4.00%

Under-collection of fuel revenues

10,200,000

Number Of Transmission Lines

PUCT | Montana Power Station

Number of power generation units authorized to be constructed

NMPRC | Montana Power Station

Number of power generation units authorized to be constructed

FERC

Refund Related to Dispute

1,900,000

Caliente - Coyote Transmission Line

Electric capacity

115

Phase II of Construction | PUCT | Montana Power Station

Number of power generation units authorized to be constructed

Electric capacity

Minimum

Fixed Fuel Factor Revision Period, in Months

4 months

PUCT Docket No. 42384 | Fixed Fuel Factor

Increase (Decrease) in Fixed Fuel Factor, Amount

10,700,000

Increase (Decrease) in Fixed Fuel Factor, Percentage

6.90%

PUCT Docket No. 42384 | Scenario, Forecast

Period Of Expected Increases In Prices For Natural Gas

12 months

PUCT Docket No. 41852

Reconcilable Fuel Expense

545,300,000

Fuel Reconciliation Period

45 months

Fuel Reconciliation Settlement, Increase (Decrease) in Income Before Tax

2,100,000

Rewards For Operations Requested

3,400,000

Disallowed Reconcilable Fuel Expense

1,750,000

Disallowed Reconcilable Fuel Expense, Reserve

500,000

Intervenor Reimbursed Expenses

100,000

Retained Percentage Of Off System Sales Margins, Period Covered Start Date

1-Apr-14

Retained Percentage Of Off System Sales Margins, Period Covered End Date

30-Jun-15

PUCT Docket No. 41852 | Non-Arbitrage Sales

Customers Percentage Of Off System Sales Margins

100.00%

PUCT Docket No. 41852 | Arbitrage Sales

Customers Percentage Of Off System Sales Margins

50.00%

PUCT Docket No. 41852 | Minimum

Performance Reported Periods

1-Jan-09

PUCT Docket No. 41852 | Maximum

Performance Reported Periods

31-Dec-12

Retained Percentage Of Off System Sales Margins

10.00%

PUCT Docket No. 41360 | MPS to Caliente Transmission Line

Electric capacity

115

PUCT Docket No. 41359 | MPS In & Out Transmission Line

Electric capacity

115

PUCT Docket No. 41809 | MPS To Montwood Transmission Line

Electric capacity

115

Four Corners Generating Station

Date participation is ceased

6-Jul-16

Number of power generation units

Regulatory_Assets_and_Liabilit2

Regulatory Assets and Liabilities Regulatory Assets and Liabilities (Details) (USD $)	Dec. 31, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Regulatory Assets and Liabilities [Line Items]
Total regulatory assets	$112,086		$101,050
Total regulatory liabilities	26,099		26,416
Regulatory tax assets or liabilities
Regulatory Assets and Liabilities [Line Items]
Total regulatory liabilities	17,252	[1],[2]	17,752	[1],[2]
Accumulated Deferred Investment Tax Credit
Regulatory Assets and Liabilities [Line Items]
Total regulatory liabilities	4,334	[1],[3]	4,656	[1],[3]
New Mexico energy efficiency
Regulatory Assets and Liabilities [Line Items]
Total regulatory liabilities	3,904	[4]	3,646	[4]
Texas energy efficiency
Regulatory Assets and Liabilities [Line Items]
Total regulatory liabilities	0	[4]	362	[4]
Texas military base discount and recovery factor
Regulatory Assets and Liabilities [Line Items]
Total regulatory liabilities	609	[5]	0	[5]
Regulatory tax assets or liabilities
Regulatory Assets and Liabilities [Line Items]
Total regulatory assets	66,134	[1],[2]	61,772	[1],[2]
Loss on reacquired debt
Regulatory Assets and Liabilities [Line Items]
Total regulatory assets	17,486	[6]	18,338	[6]
Final coal reclamation
Regulatory Assets and Liabilities [Line Items]
Total regulatory assets	10,702	[7],[8]	4,290	[7],[8]
Nuclear fuel postload daily financing charge
Regulatory Assets and Liabilities [Line Items]
Total regulatory assets	4,127	[8]	4,141	[8]
Unrecovered issuance costs due to reissuance of PCBs
Regulatory Assets and Liabilities [Line Items]
Total regulatory assets	860	[6]	893	[6]
Texas energy efficiency
Regulatory Assets and Liabilities [Line Items]
Total regulatory assets	1,817	[4]	0	[4]
Texas 2012 rate case costs
Regulatory Assets and Liabilities [Line Items]
Total regulatory assets	0		581
Texas 2015 rate case costs
Regulatory Assets and Liabilities [Line Items]
Total regulatory assets	169	[9]	0	[9]
Texas military base discount and recovery factor
Regulatory Assets and Liabilities [Line Items]
Total regulatory assets	0	[5]	759	[5]
New Mexico procurement plan costs
Regulatory Assets and Liabilities [Line Items]
Total regulatory assets	139	[9]	139	[9]
New Mexico renewable energy credits
Regulatory Assets and Liabilities [Line Items]
Total regulatory assets	5,456	[9]	4,833	[9]
New Mexico 2010 FPPCAC audit
Regulatory Assets and Liabilities [Line Items]
Total regulatory assets	434	[9]	433	[9]
New Mexico Palo Verde deferred depreciation
Regulatory Assets and Liabilities [Line Items]
Total regulatory assets	4,720	[1]	4,871	[1]
New Mexico 2015 rate case costs
Regulatory Assets and Liabilities [Line Items]
Total regulatory assets	$42	[9]	$0	[9]

[1]	The amortization period for this asset is based upon the life of the associated assets or liabilities.
[2]	No specific return on investment is required since related assets and liabilities offset.
[3]	This item is excluded from rate base.
[4]	This item is recovered or credited through a recovery factor that is set annually.
[5]	This item represents the net asset/net liability related to the military discount which is recovered from non-military customers through a recovery factor.
[6]	This item is recovered as a component of the weighted cost of debt and amortized over the life of the related debt issuance.
[7]	This item and the related final coal reclamation liability have been included or will be requested in rate base.
[8]	This item is recovered through fuel recovery mechanisms.
[9]	Amortization period is anticipated to be established in next general rate case.

Utility_Plant_Palo_Verde_and_O2

Utility Plant, Palo Verde and Other Jointly-Owned Utility Plant (Depreciable Assets By Each Major Class) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment and Finite-Lived Intangible Assets [Line Items]
Gross Plant	$3,229,255	$3,076,549
Accumulated Depreciation	-1,266,672	-1,214,088
Net plant in service	1,962,583
Intangible Plant Software
Property, Plant and Equipment and Finite-Lived Intangible Assets [Line Items]
Gross Plant	75,201
Accumulated Depreciation	-45,039
Net plant in service	30,162
Energy Equipment \| Nuclear production
Property, Plant and Equipment and Finite-Lived Intangible Assets [Line Items]
Gross Plant	874,817
Accumulated Depreciation	-286,585
Net plant in service	588,232
Energy Equipment \| Steam and other
Property, Plant and Equipment and Finite-Lived Intangible Assets [Line Items]
Gross Plant	684,863
Accumulated Depreciation	-284,764
Net plant in service	400,099
Energy Equipment \| Total production
Property, Plant and Equipment and Finite-Lived Intangible Assets [Line Items]
Gross Plant	1,559,680
Accumulated Depreciation	-571,349
Net plant in service	988,331
Energy Equipment \| Transmission
Property, Plant and Equipment and Finite-Lived Intangible Assets [Line Items]
Gross Plant	433,982
Accumulated Depreciation	-250,941
Net plant in service	183,041
Energy Equipment \| Distribution
Property, Plant and Equipment and Finite-Lived Intangible Assets [Line Items]
Gross Plant	1,020,901
Accumulated Depreciation	-342,931
Net plant in service	677,970
Energy Equipment \| General
Property, Plant and Equipment and Finite-Lived Intangible Assets [Line Items]
Gross Plant	139,491
Accumulated Depreciation	-56,412
Net plant in service	$83,079

Utility_Plant_Palo_Verde_and_O3

Utility Plant, Palo Verde and Other Jointly-Owned Utility Plant (Amortization of Intangible Plant Assets - Software) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment and Finite-Lived Intangible Assets [Line Items]
Number of years amortization expense prior reporting year	3 years
Number of years amortization expense after reporting year	5 years
Intangible
Property, Plant and Equipment and Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Amortization Expense	$8,051	$7,683	$7,183
Future Amortization Expense, 2015 (estimated)	7,505
Future Amortization Expense, 2016 (estimated)	7,030
Future Amortization Expense, 2017 (estimated)	6,388
Future Amortization Expense, 2018 (estimated)	4,762
Future Amortization Expense, 2019 (estimated)	$3,101
Minimum \| Intangible
Property, Plant and Equipment and Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Useful Life	5 years
Maximum \| Intangible
Property, Plant and Equipment and Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Useful Life	10 years

Utility_Plant_Palo_Verde_and_O4

Utility Plant, Palo Verde and Other Jointly-Owned Utility Plant (Summary of Jointly Owned Utility Plants) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Palo Verde
Jointly Owned Utility Plant Interests [Line Items]
Electric plant in service	$874,817	$817,665
Accumulated depreciation	-286,585	-271,173
Construction work in progress	55,632	75,040
Total	643,864	621,532
Other Jointly Owned Utlity Plant
Jointly Owned Utility Plant Interests [Line Items]
Electric plant in service	219,318	217,137
Accumulated depreciation	-176,492	-173,819
Construction work in progress	6,900	2,347
Total	$49,726	$45,665

Utility_Plant_Palo_Verde_and_O5

Utility Plant, Palo Verde and Other Jointly-Owned Utility Plant (Narrative) (Details) (USD $)

0 Months Ended

12 Months Ended

0 Months Ended

24 Months Ended

6 Months Ended

16-May-14

Mar. 30, 2011

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Oct. 31, 2014

Apr. 21, 2014

Dec. 19, 2012

Oct. 08, 2014

Aug. 18, 2014

Dec. 31, 2016

Jun. 30, 2015

Apr. 21, 2011

Jointly Owned Utility Plant Interests [Line Items]

Number of Units With Renewed Operating Licenses

Decommissioning Fund Investments

$234,286,000

$214,095,000

Third Party Decommission Cost Estimates Study Period, in Years

3 years

Estimated Decommissioning Costs

380,700,000

Decommission cost increase

23,300,000

Asset Retirement Obligation, Revision of Estimate

-3,561,000

3,401,000

-1,929,000

Period of environmental impact study needed to be done

24 months

Spent Nuclear Fuel Disposal Fee, per kWh

0.001

Period to Conduct an Adequacy Assessment Analysis

6 months

One-Mill Fee Suspended, Date

16-May-14

Number of governmental rule orders

Additional cost related to NRC enhancements

6,300,000

NRC Enhancements

12,600,000

Retrospective Premium Adjustments Due to Nuclear Facility Losses

10,900,000

Palo Verde Generating Station

Jointly Owned Utility Plant Interests [Line Items]

Jointly Owned Utility Plant, Proportionate Ownership Share

15.80%

Jointly Owned Utility Plant, Number of Units

Asset Retirement Obligation, Revision of Estimate

-1,900,000

Maximum Assesment Per Reactor Nuclear Energy Incident

60,400,000

Maximum Assesment Per Reactor Nuclear Energy Incident Annual Limit

9,000,000

Palo Verde Participants

Jointly Owned Utility Plant Interests [Line Items]

Jointly Owned Plant, Number of Participants

Additional cost related to NRC enhancements

40,000,000

NRC Enhancements

80,000,000

Nuclear Energy Hazards Full Limit Of Liability Under Federal Law

13,600,000,000

Nuclear Energy Hazards Potential Liability

375,000,000

Maximum Assesment Per Reactor Nuclear Energy Incident

127,300,000

Maximum Assesment Per Reactor Nuclear Energy Incident Annual Limit

19,000,000

Aggregate Amount of Insurance for Decontamination and Property Damage

2,800,000,000

Four Corners Generating Station

Jointly Owned Utility Plant Interests [Line Items]

Jointly Owned Utility Plant, Proportionate Ownership Share

7.00%

Date participation is ceased

6-Jul-16

Decommissioning Liability, Noncurrent

6,100,000

Mine Reclamation and Closing Liability, Noncurrent

19,300,000

Four Corners Coal Plant Participants

Jointly Owned Utility Plant Interests [Line Items]

Participation agreement expiration date

6-Jul-16

Suit Against Department of Energy for Spent Fuel

Jointly Owned Utility Plant Interests [Line Items]

Lawsuit Filing Date

31-Oct-14

19-Dec-12

Settlement Agreement, Counterparty's Name

United States Department of Energy

Litigation, Period Covered Start Date

1-Jul-11

1-Jan-07

Litigation, Period Covered End Date

30-Jun-14

30-Jun-11

Suit Against Department of Energy for Spent Fuel | Palo Verde Generating Station

Jointly Owned Utility Plant Interests [Line Items]

Settlement, Amount

9,100,000

Settlement Agreement Award Received, Date

8-Oct-14

Reimbursement requested, Amount

6,700,000

Suit Against Department of Energy for Spent Fuel | Palo Verde Participants

Jointly Owned Utility Plant Interests [Line Items]

Settlement, Amount

57,400,000

Reimbursement requested, Amount

42,500,000

Scenario, Forecast

Jointly Owned Utility Plant Interests [Line Items]

Spending Period Related To Additional NRC Enhancements Costs

2 years

Scenario, Forecast | Minimum | Suit Against Department of Energy for Spent Fuel

Jointly Owned Utility Plant Interests [Line Items]

Reimbursement anticipated to be received

1-Jan-15

Scenario, Forecast | Maximum | Suit Against Department of Energy for Spent Fuel

Jointly Owned Utility Plant Interests [Line Items]

Reimbursement anticipated to be received

30-Jun-15

Limited amount of coverage | Palo Verde Participants

Jointly Owned Utility Plant Interests [Line Items]

Aggregate Amount of Insurance for Decontamination and Property Damage

$2,300,000,000

Accounting_for_Asset_Retiremen2

Accounting for Asset Retirement Obligations (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Accounting For Asset Retirement Obligations [Line Items]
Number of External Trust Funds with Independent Trustee with Legal Restrictions To Settling ARO	6
Decommissioning Fund Investments	$234,286	$214,095

Accounting_for_Asset_Retiremen3

Accounting for Asset Retirement Obligations (Changes in Estimated Probabilities Assumptions) (Details)	12 Months Ended
	Dec. 31, 2014
Original ARO Liability [Member]
Accounting For Asset Retirement Obligations [Line Items]
Escalation Rate	3.60%
Credit-Risk Adjusted Discount Rate	9.50%
Incremental ARO Liability [Member]
Accounting For Asset Retirement Obligations [Line Items]
Escalation Rate	3.60%
Credit-Risk Adjusted Discount Rate	6.20%

Accounting_for_Asset_Retiremen4

Accounting for Asset Retirement Obligations (Schedule of Asset Retirement Obligations) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Asset Retirement Obligation, Roll Forward Analysis
ARO liability at beginning of year	$65,214	$62,784	$56,140
Liabilities incurred	0	0	0
Liabilities settled	0	-36	-450
Revisions to estimate	3,561	-3,401	1,929
Accretion expense	5,802	5,867	5,165
ARO liability at end of year	$74,577	$65,214	$62,784

Common_Stock_Common_Stock_Deta

Common Stock Common Stock (Details) (USD $)

0 Months Ended

3 Months Ended

12 Months Ended

0 Months Ended

In Thousands, except Share data, unless otherwise specified

Dec. 30, 2014

Dec. 31, 2014

Sep. 30, 2014

Jun. 30, 2014

Mar. 31, 2014

Dec. 31, 2013

Sep. 30, 2013

Jun. 30, 2013

Mar. 31, 2013

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Mar. 31, 2015

Mar. 16, 2015

Jan. 29, 2015

29-May-14

Common Stock [Line Items]

Dividends, Common Stock, Cash

$11,300

$44,556

$42,049

$38,889

Common Stock, Dividends, Per Share, Declared

$0.28

$0.27

$0.25

$1.10

$1.04

$0.97

Common Stock, Par or Stated Value Per Share

Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized

1,700,000

Restricted Stock | Minimum

Common Stock [Line Items]

Share-based Compensation Arrangement by Share-based Payment Award, Award Requisite Service Period

1 year

Restricted Stock | Maximum

Common Stock [Line Items]

Share-based Compensation Arrangement by Share-based Payment Award, Award Requisite Service Period

3 years

Scenario, Forecast

Common Stock [Line Items]

Dividends Payable, Date to be Paid

31-Mar-15

Dividends Payable, Date of Record

16-Mar-15

Subsequent Event

Common Stock [Line Items]

Dividends Payable, Date Declared

29-Jan-15

Common Stock, Dividends, Per Share, Declared

$0.28

Common_Stock_ShareBased_Compen

Common Stock (Share-Based Compensation Options) (Details) (Stock Options, USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options, expiration period		10 years
Stock options outstanding, in shares	0	0	15,000
Stock options exercised, in shares		15,000
Cash received		$200,000
Weighted average exercise price, options exercised		$12.78
Realized current tax benefits		100,000
Intrinsic value of stock options exercised		300,000	600,000
Stock options forfeited, vested and expired in period	0	0	0
Allocated share-based compensation expense	$0	$0	$0

Common_Stock_Schedule_of_Restr

Common Stock (Schedule of Restricted Stock Tax Expense and Deferred Tax) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Deferred tax benefit	$39,129		$44,678		$43,561
Capitalized costs related to restricted stock award or unit expense	100		100		100
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	3,471	[1]	2,458	[1]	1,508	[1]
Deferred tax benefit	1,215		860		528
Current tax expense (benefit) recognized	$39		$109		$94

[1]	Any capitalized costs related to these expenses is less than $0.1 million for all years.

Common_Stock_Vested_Restricted

Common Stock (Vested Restricted Stock Aggregate Intrinsic Value And Grant Date Fair Value) (Details) (Restricted Stock, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted shares vested - aggregated intrinsic value	$3,441	$2,077	$2,242
Fair value at grant date	$3,330	$1,765	$1,973

Common_Stock_Schedule_of_Unves

Common Stock (Schedule of Unvested Restricted Stock) (Details) (USD $)	0 Months Ended	12 Months Ended
In Thousands, except Share data, unless otherwise specified	29-May-14	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Share price	37.81
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Share based compensation, outstanding at beginning of period, in shares	13,863	120,534
Total restricted stock awards, in shares	13,863	113,776
Total vested, in shares	-13,863	-90,851
Total forfeitures, in shares	-13,863	-19,162
Share based compensation, outstanding at end of period, in shares		124,297		120,534
Shares outstanding, weighted average grant date fair value,beginning of period		$35.19
Weighted average fair value per share		$36.95		$35.48	$32.45
Weighted average fair value vested		$36.66
Weighted average fair value forfeitures		$34.72
Shares outstanding, weighted average grant date fair value, end of period		$35.81		$35.19
Restricted shares outstanding		$1,662	[1]
Aggregated intrinsic value for restricted stock oustanding at end of period		$4,979
Employee service share-based compensation, nonvested awards, total compensation cost not yet recognized, period for recognition		1 year

[1]	The unrecognized compensation expense is expected to be recognized over the weighted average remaining contractual term of the outstanding restricted stock of approximately one year.

Common_Stock_Weighted_Average_

Common Stock (Weighted Average Fair Value Per Share) (Details) (Restricted Stock, USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value per share	$36.95	$35.48	$32.45

Common_Stock_Performance_Share

Common Stock (Performance Shares) (Details) (USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
The Number of Simulations on Fair Value of Average Payout	1,000,000
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance Shares Payout Level	0.00%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance Shares Payout Level	200.00%
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based payment award on performance, performance evaluation period	3 years
Performance shares vested - aggregated intrinsic value	$0	[1]	$1,450	[1]	$3,464	[1]
Performance Shares Payout Level	100.00%
Performance Shares \| Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance shares vested - Performance Shares Awarded	0
Performance Shares \| Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance shares vested - Performance Shares Awarded	145,496
February 20, 2015 \| Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance shares vested - Payout Ratio	0.00%
Performance shares vested - Performance Shares Awarded	0
Performance shares vested - Compensation Costs Expensed	1,502
Performance shares vested - aggregated intrinsic value	0
February 18, 2014 \| Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance shares vested - Payout Ratio	0.00%
Performance shares vested - Performance Shares Awarded	0
Performance shares vested - Compensation Costs Expensed	954
Performance shares vested - aggregated intrinsic value	0
January 29, 2013 \| Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance shares vested - Payout Ratio	150.00%
Performance shares vested - Performance Shares Awarded	64,275
Performance shares vested - Compensation Costs Expensed	849
Performance shares vested - aggregated intrinsic value	2,176
January 1, 2012 \| Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance shares vested - Payout Ratio	175.00%
Performance shares vested - Performance Shares Awarded	174,038
Performance shares vested - Compensation Costs Expensed	1,193
Performance shares vested - aggregated intrinsic value	$6,029

[1]	Based on a 100% performance level.

Common_Stock_Outstanding_Perfo

Common Stock (Outstanding Performance Share Awards) (Details) (Performance Shares, USD $)	12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance Shares Payout Level	100.00%
Share based compensation, outstanding at beginning of period, in shares	124,997
Performance shares awards, number of shares awarded in period	37,561
Performace shares awards, number of shares lapsed in period	-34,050
Performance shares award, number of shares forfeited in period	-7,027
Share based compensation, outstanding at end of period, in shares	121,481		124,997
Shares outstanding, weighted average grant date fair value,beginning of period	$31.38
Performance shares awards, Weighted Average Grant Date Fair Value	$26.36		$34.69	$32.74
Performance shares lapsed, weighted average grant date fair value	$28.03
Performance shares forfeited, Weighted Average Grant Date Fair Value	$32.24
Shares outstanding, weighted average grant date fair value, end of period	$30.71		$31.38
Performance shares outstanding, unrecognized compensation expense	$975	[1]
Performance shares outstanding, Aggregate Intrinsic Value	$4,867
Employee service share-based compensation, nonvested awards, total compensation cost not yet recognized, period for recognition	1 year

[1]	The unrecognized compensation expense is expected to be recognized over the weighted average remaining contractual term of the awards of approximately one year.

Common_Stock_Performance_Share1

Common Stock (Performance Share Summary) (Details) (Performance Shares, USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average per share grant date fair value per share of performance shares awarded	$26.36		$34.69		$32.74
Fair value of performance shares vested	$0		$849		$1,193
Performance shares vested - aggregated intrinsic value	0	[1]	1,450	[1]	3,464	[1]
Share-based compensation expense	1,181	[2]	1,188	[2]	170	[2]
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense	$413		$416		$59

[1]	Based on a 100% performance level.
[2]	Includes adjustments for forfeiture of performance share awards by certain executives.

Common_Stock_Common_Stock_Repu

Common Stock (Common Stock Repurchase Program) (Details) (USD $)	12 Months Ended	192 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2014
Equity, Class of Treasury Stock [Line Items]
Shares repurchased	0	25,406,184	[1],[2]
Cost, including commission		$423,647	[2]
Total remaining shares available for repurchase at December 31, 2014	393,816	393,816
Treasury shares acquired outside of repurchase programs		86,735

[1]	Shares repurchased does not include 86,735 treasury shares related to employee compensation arrangements outside of the Company's repurchase programs.
[2]	Represents repurchased shares and cost since inception of the stock repurchase program in 1999.

Common_Stock_Basic_and_Diluted

Common Stock (Basic and Diluted Earnings Per Share) (Details) (USD $)	3 Months Ended								12 Months Ended
In Thousands, except Share data, unless otherwise specified	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Class of Stock Disclosures [Abstract]
Basic number of common shares outstanding									40,190,991	40,114,594	39,974,022
Dilutive effect of unvested performance awards									20,726	12,053	66,756
Dilutive effect of stock options									0	0	14,803
Diluted number of common shares outstanding									40,211,717	40,126,647	40,055,581
Net income	$4,241	$52,476	$30,096	$4,615	$1,191	$50,565	$29,193	$7,634	$91,428	$88,583	$90,846
Income allocated to participating restricted stock									-301	-254	-256
Net income available to common shareholders basic									91,127	88,329	90,590
Income reallocated to participating restricted stock									-301	-254	-256
Net income available to common shareholders diluted									$91,127	$88,329	$90,590
Earnings Per Share, Basic, Distributed									$1.10	$1.04	$0.97
Earnings Per Share, Basic, Undistributed									$1.17	$1.16	$1.30
Basic net income per common share	$0.10	$1.30	$0.75	$0.11	$0.03	$1.26	$0.73	$0.19	$2.27	$2.20	$2.27
Earnings Per Share, Diluted, Distributed									$1.10	$1.04	$0.97
Earnings Per Share, Diluted, Undistributed									$1.17	$1.16	$1.29
Diluted net income per common share	$0.10	$1.30	$0.75	$0.11	$0.03	$1.26	$0.72	$0.19	$2.27	$2.20	$2.26

Common_Stock_Antidilutive_Shar

Common Stock (Antidilutive Shares) (Details)	12 Months Ended
Common Stock (Antidilutive Shares) (Details)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Restricted Stock
Common Stock [Line Items]
Antidilutive Securities Excluded from Computation of Diluted Earnings Per Share, Amount	60,455	51,489	45,178
Performance Shares
Common Stock [Line Items]
Performance Shares Payout Level	100.00%	100.00%	100.00%
Antidilutive Securities Excluded from Computation of Diluted Earnings Per Share, Amount	96,208	115,044	57,625	[1]
Performance shares payout based upon performance	0	0	0

[1]	Certain performance shares were excluded from the computation of diluted earnings per share as no payouts would have been required based upon performance at the end of each corresponding period.

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Income by Component (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), beginning balance	$2,612	($66,084)
Other Comprehensive Income (Loss) Before Reclassifications	-3,934	65,853
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)	-6,679	2,843
Accumulated Other Comprehensive Income (Loss), ending balance	-8,001	2,612
Accumulated Defined Benefit Plans Adjustment
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), beginning balance	-21,330	-75,737
Other Comprehensive Income (Loss) Before Reclassifications	-12,628	51,371
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)	-926	3,036
Accumulated Other Comprehensive Income (Loss), ending balance	-34,884	-21,330
Accumulated Net Unrealized Investment Gain (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), beginning balance	36,240	22,194
Other Comprehensive Income (Loss) Before Reclassifications	8,694	14,482
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)	-5,977	-436
Accumulated Other Comprehensive Income (Loss), ending balance	38,957	36,240
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), beginning balance	-12,298	-12,541
Other Comprehensive Income (Loss) Before Reclassifications	0	0
Amount Reclassified from Accumulated Other Comprehensive Income (Loss)	224	243
Accumulated Other Comprehensive Income (Loss), ending balance	($12,074)	($12,298)

Accumulated_Other_Comprehensiv3

Accumulated Other Comprehensive Income Amounts Reclassified (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]
Prior service benefit	$7,659		$5,560		$5,762
Interest on long-term debt and revolving credit facility	-46,818		-47,712		-44,937
Income tax expense	41,088		43,655		46,979
Net income (loss)	91,127		88,329		90,590
Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net income (loss)	6,679		-2,843
Reclassification out of Accumulated Other Comprehensive Income \| Accumulated Defined Benefit Plans Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Prior service benefit	7,659	[1]	5,560	[1]
Net loss	-6,182	[1]	-10,472	[1]
Income (Loss) before income tax	1,477	[1]	-4,912	[1]
Income tax expense	-551		1,876
Net income (loss)	926	[1]	-3,036	[1]
Reclassification out of Accumulated Other Comprehensive Income \| Accumulated Net Unrealized Investment Gain (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net Realized Gain on Sale of Securities	7,350		553
Income (Loss) before income tax	7,350		553
Income tax expense	-1,373		-117
Net income (loss)	5,977		436
Reclassification out of Accumulated Other Comprehensive Income \| Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Interest on long-term debt and revolving credit facility	-438		-411
Income (Loss) before income tax	-438		-411
Income tax expense	214		168
Net income (loss)	($224)		($243)

[1]	These items are included in the computation of net periodic benefit cost. See Note M, Employee Benefits, for additional information.

LongTerm_Debt_and_Financing_Ob2

Long-Term Debt and Financing Obligations Outstanding Balance (Details) (USD $)

1 Months Ended

0 Months Ended

In Thousands, unless otherwise specified

Jun. 29, 2008

Jan. 14, 2014

Dec. 31, 2014

Dec. 31, 2013

2-May-05

Jun. 02, 2008

Dec. 06, 2012

Dec. 01, 2014

Aug. 18, 2010

Aug. 31, 2010

Aug. 28, 2012

1-May-05

Jun. 01, 2008

Debt Instrument [Line Items]

Long-term Debt

$1,163,711

$1,013,972

Long-term Debt, Current Maturities

-15,000

Line of Credit, Current

-14,532

-14,352

Long-term debt

1,134,179

999,620

Nuclear Fuel Financing

Debt Instrument [Line Items]

Long-term Line of Credit

14,500

14,400

Working Capital and General Purpose

Debt Instrument [Line Items]

Long-term Line of Credit

Short Term Borrowing

Debt Instrument [Line Items]

Repayments of Short-term Debt

44,000

Revolving Credit Facility

Debt Instrument [Line Items]

Long-term Line of Credit

14,532

Line of Credit Weighted Average Interest Rate

1.30%

Revolving Credit Facility | Nuclear Fuel Financing

Debt Instrument [Line Items]

Long-term Line of Credit

14,500

Revolving Credit Facility | Working Capital and General Purpose

Debt Instrument [Line Items]

Long-term Line of Credit

Revolving Credit Facility Expiring January 2019

Debt Instrument [Line Items]

Line of Credit Facility, Expiration Date

14-Jan-19

Line of Credit renewal option, renewal times

Line of Credit renewal term, year

1 year

Line of Credit Facility, Current Borrowing Capacity

300,000

Line of Credit Facility, Maximum Borrowing Capacity

400,000

Line of Credit Facility, Increase (Decrease), Net

100,000

Bonds and Notes

Debt Instrument [Line Items]

Long-term Debt

1,149,179

999,620

Pollution Control Bonds

Debt Instrument [Line Items]

Long-term Debt

193,135

[1]

193,135

[1]

Number of tax exempt bond series

Pollution Control Bonds | 7.25% 2009 Series A Refunding Bonds, due 2040

Debt Instrument [Line Items]

Long-term Debt

63,500

[1]

63,500

[1]

Debt Instrument, Interest Rate, Effective Percentage

7.46%

Debt Instrument, Maturity Date

1-Feb-40

Debt Instrument, Interest Rate, Stated Percentage

7.25%

Pollution Control Bonds | 4.50% 2012 Series A Refunding Bonds, due 2042

Debt Instrument [Line Items]

Long-term Debt

59,235

[1]

59,235

[1]

Debt Instrument, Interest Rate, Effective Percentage

4.63%

Debt Instrument, Maturity Date

1-Aug-42

Debt Instrument, Interest Rate, Stated Percentage

4.50%

Pollution Control Bonds | 7.25% 2009 Series B Refunding Bonds, due 2040

Debt Instrument [Line Items]

Long-term Debt

37,100

[1]

37,100

[1]

Debt Instrument, Interest Rate, Effective Percentage

7.49%

Debt Instrument, Maturity Date

1-Apr-40

Debt Instrument, Interest Rate, Stated Percentage

7.25%

Pollution Control Bonds | 1.875% 2012 Series A Refunding Bonds, due 2032

Debt Instrument [Line Items]

Long-term Debt

33,300

[1]

33,300

[1]

Debt Instrument, Interest Rate, Effective Percentage

2.35%

Debt Instrument, Maturity Date

1-Jun-32

Debt Instrument, Interest Rate, Stated Percentage

1.88%

Debt Instrument Remarketed Date, Year

30-Sep-17

Debt Instrument, Face Amount

33,300

Senior Notes

Debt Instrument [Line Items]

Long-term Debt

846,044

[2]

696,485

[2]

Senior Notes | 6.00% Senior Notes, Net of Discount, due 2035

Debt Instrument [Line Items]

Long-term Debt

398,021

[2]

397,976

[2]

Debt Instrument, Interest Rate, Effective Percentage

7.12%

Debt Instrument, Maturity Date

15-May-35

Debt Instrument, Interest Rate, Stated Percentage

6.00%

Debt Instrument, Face Amount

400,000

Debt Instrument, Issuance Date

1-May-05

Debt Instrument, Unamortized Discount

2,300

Senior Notes | 7.50% Senior Notes, Net of Discount, due 2038

Debt Instrument [Line Items]

Long-term Debt

148,818

[2]

148,800

[2]

Debt Instrument, Interest Rate, Effective Percentage

7.67%

Debt Instrument, Maturity Date

15-Mar-38

Debt Instrument, Interest Rate, Stated Percentage

7.50%

Debt Instrument, Face Amount

150,000

Debt Instrument, Issuance Date

1-Jun-08

Debt Instrument, Unamortized Discount

1,300

Senior Notes | 3.30% Senior Notes, Net of Discount, due 2022

Debt Instrument [Line Items]

Long-term Debt

149,737

[2]

149,709

[2]

Debt Instrument, Interest Rate, Effective Percentage

3.43%

Debt Instrument, Maturity Date

15-Dec-22

Debt Instrument, Interest Rate, Stated Percentage

3.30%

Debt Instrument, Face Amount

150,000

Debt Instrument, Issuance Date

6-Dec-12

Debt Instrument, Unamortized Discount

300

Senior Notes | 5.00% Senior Notes, Net of Discount, due 2044

Debt Instrument [Line Items]

Long-term Debt

149,468

[2]

Debt Instrument, Interest Rate, Effective Percentage

5.10%

Debt Instrument, Maturity Date

1-Dec-44

Debt Instrument, Interest Rate, Stated Percentage

5.00%

Debt Instrument, Face Amount

150,000

Debt Instrument, Issuance Date

1-Dec-14

Debt Instrument, Unamortized Discount

500

RGRT Senior Notes

Debt Instrument [Line Items]

Long-term Debt

110,000

[3]

110,000

[3]

Debt Instrument, Face Amount

110,000

Redemption Price of Notes Equal to Principal Amount, Percentage

100.00%

Proceeds from Issuance of Long-term Debt

109,400

RGRT Senior Notes | 3.67% Senior Notes, Series A, due 2015

Debt Instrument [Line Items]

Long-term Debt

15,000

[3]

15,000

[3]

Long-term Debt, Current Maturities

-15,000

Debt Instrument, Interest Rate, Effective Percentage

3.87%

Debt Instrument, Maturity Date

15-Aug-15

Debt Instrument, Interest Rate, Stated Percentage

3.67%

RGRT Senior Notes | 4.47% Senior Notes, Series B, due 2017

Debt Instrument [Line Items]

Long-term Debt

50,000

[3]

50,000

[3]

Debt Instrument, Interest Rate, Effective Percentage

4.62%

Debt Instrument, Maturity Date

15-Aug-17

Debt Instrument, Interest Rate, Stated Percentage

4.47%

RGRT Senior Notes | 5.04% Senior Notes, Series C, due 2020

Debt Instrument [Line Items]

Long-term Debt

45,000

[3]

45,000

[3]

Debt Instrument, Interest Rate, Effective Percentage

5.16%

Debt Instrument, Maturity Date

15-Aug-20

Debt Instrument, Interest Rate, Stated Percentage

5.04%

Financing Obligations | Revolving Credit Facility

Debt Instrument [Line Items]

Long-term Line of Credit

$14,532

[4]

$14,352

[4]

[1]

Pollution Control Bonds ("PCBs")The Company has four series of tax exempt unsecured PCBs in aggregate principal amount of $193.1 million. The 1.875% 2012 Series A (El Paso Electric Company Four Corners Project) Pollution Control Refunding Revenue Bonds with an aggregate principal amount of $33.3 million are subject to mandatory tender for purchase in September 2017.

[2]

Senior NotesThe Senior Notes are unsecured obligations of the Company. They were issued pursuant to bond covenants that provide limitations on the Companybs ability to enter into certain transactions. The 6.00% Senior Notes have an aggregate principal amount of $400.0 million and were issued in May 2005. The proceeds, net of a $2.3 million discount, were used to fund the retirement of the Company's first mortgage bonds. The Company amortizes the loss associated with a cash flow hedge recorded in accumulated other comprehensive income to earnings as interest expense over the life of the 6.00% Senior Notes. See Note O, "Financial Instruments and Investments - Treasury Rate Locks". This amortization is included in the effective interest rate of the 6.00% Senior Notes. The 7.50% Senior Notes have an aggregate principal amount of $150.0 million and were issued in June 2008. The proceeds, net of a $1.3 million discount, were used to repay short-term borrowings of $44.0 million, fund capital expenditures and for other general corporate purposes.The 3.30% Senior Notes have an aggregate principal amount of $150.0 million and were issued in December 2012. The proceeds, net of a $0.3 million discount, were used to fund construction expenditures and for working capital and general corporate purposes.The 5.00% Senior Notes have an aggregate principal amount of $150.0 million and were issued in December 2014. The proceeds, net of a $0.5 million discount, were used to fund construction expenditures and for working capital and general corporate purposes.

[3]

RGRT Senior NotesIn 2010, the Company and RGRT, a Texas grantor trust through which the Company finances its portion of fuel for PaloB Verde, entered into a note purchase agreement with various institutional purchasers. Under the terms of the agreement, RGRT sold to the purchasers $110 million aggregate principal amount of Senior Notes (the "Notes") of which $15.0 million will mature in August 2015. The Company will either repay or refinance this $15.0 million of Notes upon maturity. The Company guarantees the payment of principal and interest on the Notes. In the Companybs financial statements, the assets and liabilities of the RGRT are reported as assets and liabilities of the Company.RGRT pays interest on the Notes on February 15, and AugustB 15 of each year until maturity. RGRT may redeem the Notes, in whole or in part, at any time at a redemption price equal to 100% of the principal amount to be redeemed together with the interest on such principal amount accrued to the date of redemption, plus a make-whole amount based on the prevailing market interest rates. The agreement requires compliance with certain covenants, including a total debt to capitalization ratio. The Company was in compliance with these requirements throughout 2014.The sale of the Notes was made by RGRT in reliance on a private placement exemption from registration under the Securities Act of 1933, as amended. The proceeds of $109.4 million, net of issuance costs, from the sale of the Notes was used by RGRT to repay amounts borrowed under the revolving credit facility and will enable future nuclear fuel financing requirements of RGRT to be met with a combination of the Notes and amounts borrowed from the RCF.

[4]

Revolving Credit FacilityOn January 14, 2014, the Company and RGRT entered into a second amended and restated credit agreement related to the RCF with JPB Morgan Chase Bank, N.A., as administrative agent and issuing bank, and Union Bank, N.A., as syndication agent, and various lending banks party thereto. Under the terms of the agreement, the Company has available $300 million and the ability to increase the RCF by up to $100 million (up to a total of $400 million) upon the satisfaction of certain conditions, more fully set forth in the agreement, including obtaining commitments from lenders or third party financial institutions. The RCF has a term ending January 2019. The Company may extend the maturity date up to two times, in each case for an additional one year period upon the satisfaction of certain conditions.The RCF provides that amounts borrowed by the Company may be used for, among other things, working capital and general corporate purposes. Any amounts borrowed by RGRT may be used, among other things, to finance the acquisition and processing of nuclear fuel. Amounts borrowed by RGRT are guaranteed by the Company and the balance borrowed under the RCF is recorded as short-term borrowings on the balance sheet. The RCF is unsecured. The RCF requires compliance with certain covenants, including a total debt to capitalization ratio. The Company was in compliance with these requirements throughout 2014. As of DecemberB 31, 2014, the total amount borrowed by RGRT was $14.5 million for nuclear fuel under the RCF. As of DecemberB 31, 2014, no borrowings were outstanding under this facility for working capital and general corporate purposes. The weighted average interest rate on the RCF was 1.3% as of DecemberB 31, 2014.

LongTerm_Debt_and_Financing_Ob3

Long-Term Debt and Financing Obligations Long-term Debt Maturities (Details) (USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified	Dec. 31, 2014
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Year One	$15,000
Long-term Debt, Maturities, Repayments of Principal in Year Two	0
Long-term Debt, Maturities, Repayments of Principal in Year Three	83,300
Long-term Debt, Maturities, Repayments of Principal in Year Four	0
Long-term Debt, Maturities, Repayments of Principal in Year Five	0
Nuclear Fuel Financing \| Revolving Credit Facility
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Year One	$14,500

Income_Taxes_Deferred_Tax_Asse

Income Taxes (Deferred Tax Assets and Liabilities) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Deferred tax assets:
Benefit of tax loss carryforwards	$0	$17,709
Alternative minimum tax credit carryforward	17,701	21,638
Pensions and benefits	64,407	54,652
Asset retirement obligation	25,725	23,727
Other	15,768	14,485
Total gross deferred tax assets	123,601	132,211
Deferred tax liabilities:
Plant, principally due to depreciation and basis differences	-536,264	-511,847
Decommissioning	-40,373	-35,489
Deferred fuel	-3,531	-2,171
Other	-3,630	-5,664
Total gross deferred tax liabilities	-583,798	-555,171
Net accumulated deferred income taxes	($460,197)	($422,960)

Income_Taxes_Recognized_Income

Income Taxes (Recognized Income Tax Expense) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Federal:
Current	($1,250)	($2,877)	$1,487
Deferred	38,810	45,024	43,187
Total federal income tax	37,560	42,147	44,674
State:
Current	3,209	1,854	1,931
Deferred	641	-414	697
Total state income tax	3,850	1,440	2,628
Generation (amortization) of accumulated investment tax credits	-322	68	-323
Total income tax expense	$41,088	$43,655	$46,979

Income_Taxes_Income_Tax_Provis

Income Taxes (Income Tax Provisions) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Examination [Line Items]
Federal income tax expense computed on income at statutory rate	$46,381	$46,283	$48,239
Difference due to:
State taxes, net of federal benefit	1,902	936	1,708
AEFUDC	-3,757	-2,149	-1,845
Permanent tax differences	-2,921	-1,153	-604
Other	-517	-262	-519
Total income tax expense	$41,088	$43,655	$46,979
Effective income tax rate	31.00%	33.00%	34.10%

Income_Taxes_Unrecognized_Tax_

Income Taxes (Unrecognized Tax Benefits)[Roll Forward] (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Balance at beginning of period	$7,200	$9,800	$9,500
Additions for tax positions related to the current year	300	600	1,600
Reductions for tax positions related to the current year	0	0	-900
Additions for tax positions of prior years	2,200	1,700	1,400
Reductions for tax positions of prior years	-4,500	-4,900	-1,800
Balance at end of period	$5,200	$7,200	$9,800

Income_Taxes_Details

Income Taxes (Details) (USD $)	12 Months Ended
Income Taxes (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax [Line Items]
Period of Average Annual Book Income Before Taxes	3 years
Deferred Tax Assets, Tax Credit Carryforwards, Alternative Minimum Tax	$17,701,000	$21,638,000
Federal statutory tax rate	35.00%	35.00%	35.00%
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions	300,000	600,000	1,600,000
Unrecognized tax benefits, Increase (Decrease) resulting from tax positions taken in prior and current period tax returns.	2,100,000	500,000	1,400,000
Unrecognized tax benefits that would impact effective tax rate	3,000,000
Unrecognized tax benefits, interest on income taxes expense (benefit)	100,000	200,000	-300,000
Unrecognized tax benefits, income tax penalties and interest accrued	500,000	400,000
Internal Revenue Service (IRS)
Income Tax [Line Items]
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities	2,800,000
State and Local Jurisdiction
Income Tax [Line Items]
Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions	500,000
Minimum \| TEXAS
Income Tax [Line Items]
Income Tax Examination, Year under Examination	2007
Minimum \| ARIZONA
Income Tax [Line Items]
Income Tax Examination, Year under Examination	2009
Maximum \| Internal Revenue Service (IRS)
Income Tax [Line Items]
Tax Year Closed	2009
Maximum \| NEW MEXICO
Income Tax [Line Items]
Tax Year Closed	2009
Maximum \| TEXAS
Income Tax [Line Items]
Income Tax Examination, Year under Examination	2011
Maximum \| ARIZONA
Income Tax [Line Items]
Income Tax Examination, Year under Examination	2012
Tax Increase Prevention Act of 2014
Income Tax [Line Items]
Current Income Tax Expense (Benefit), Change in Tax Law	800,000
Change in Accounting Method Accounted for as Change in Estimate \| Internal Revenue Service (IRS)
Income Tax [Line Items]
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities		4,500,000
Tax credit taken \| ARIZONA
Income Tax [Line Items]
Unrecognized Tax Benefits, Decrease Resulting from Settlements with Taxing Authorities		400,000
Increase (Decrease) in Unrecognized Tax Position of Prior Years Recorded, net	-1,300,000	1,300,000
Unrecognized Tax Benefits, Increase Resulting from Settlements with Taxing Authorities	$400,000
Settlement with Taxing Authority \| Maximum \| ARIZONA
Income Tax [Line Items]
Tax Year Closed	2008
Settlement with Taxing Authority \| Earliest Tax Year \| ARIZONA
Income Tax [Line Items]
Tax Year Closed	1998
Settlement with Taxing Authority \| Latest Tax Year \| ARIZONA
Income Tax [Line Items]
Tax Year Closed	2007

Commitments_Contingencies_and_2

Commitments, Contingencies and Uncertainties (Power Purchase and Sale Agreement) (Details)	12 Months Ended
	Dec. 31, 2014
	MW
Freeport Agreement 3 - 25 MW
Long-term Purchase Commitment [Line Items]
Long-Term Purchase commitment, Maximum Quantity	25
Long-term Purchase Commitment, Time Period	7 years 1 month
Long-Term Sale Commitment, Maximum Quantity	25
Long-Term Sale Commitment, Time Period	7 years 1 month
Freeport Agreement 2 - 100 MW
Long-term Purchase Commitment [Line Items]
Long-Term Purchase commitment, Maximum Quantity	100
Long-term Purchase Commitment, Time Period	15 years 7 months
Long-Term Sale Commitment, Maximum Quantity	100
Long-Term Sale Commitment, Time Period	15 years 7 months
Hatch Solar Energy Center I
Long-term Purchase Commitment [Line Items]
Long-Term Purchase commitment, Maximum Quantity	5
Long-term Purchase Commitment, Time Period	25 years
Plant Commercial Operation Date	1-Jul-11
NRG
Long-term Purchase Commitment [Line Items]
Long-Term Purchase commitment, Maximum Quantity	20
Long-term Purchase Commitment, Time Period	20 years 1 month
Plant Commercial Operation Date	1-Aug-11
Sun Edison 1
Long-term Purchase Commitment [Line Items]
Long-Term Purchase commitment, Maximum Quantity	10
Long-term Purchase Commitment, Time Period	25 years 1 month
Plant Commercial Operation Date	25-Jun-12
Sun Edison 2
Long-term Purchase Commitment [Line Items]
Long-Term Purchase commitment, Maximum Quantity	12
Long-term Purchase Commitment, Time Period	25 years 1 month
Plant Commercial Operation Date	2-May-12
Macho Springs Solar
Long-term Purchase Commitment [Line Items]
Long-Term Purchase commitment, Maximum Quantity	50
Long-term Purchase Commitment, Time Period	20 years
Plant Commercial Operation Date	23-May-14
Plant Capacity	50
PSEG El Paso Solar Energy Center
Long-term Purchase Commitment [Line Items]
Long-Term Purchase commitment, Maximum Quantity	10
Long-term Purchase Commitment, Time Period	30 years
Plant Commercial Operation Date	30-Dec-14
Freeport Agreement 1 - 125 MW
Long-term Purchase Commitment [Line Items]
Long-Term Purchase commitment, Maximum Quantity	125
Long-term Purchase Commitment, Time Period	1 year
Long-Term Sale Commitment, Maximum Quantity	125
Long-Term Sale Commitment, Time Period	1 year
Ownership Capacity	190
Long-term Contract for Purchase of Electric Power, Date of Contract Expiration	31-Dec-15
Long-Term Contract For Sale Of Electric Power Date Of Contract Expiration	31-Dec-15
Sun Edison 1 and Sun Edison 2
Long-term Purchase Commitment [Line Items]
Solar Photovoltaic Projects, Number of Units	2
Shell
Long-term Purchase Commitment [Line Items]
Long-Term Contract For Purchase Of Electric Power, Contract Start Date	1-Jan-11
Long-term Contract for Purchase of Electric Power, Date of Contract Expiration	30-Sep-14
FERC \| Freeport Agreement 1 - 125 MW
Long-term Purchase Commitment [Line Items]
Long-term Contract for Purchase of Electric Power, Date of Contract Expiration	31-Dec-21
Long-Term Contract For Sale Of Electric Power Date Of Contract Expiration	31-Dec-21

Commitments_Contingencies_and_3

Commitments, Contingencies and Uncertainties (Narrative) (Details) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2014	Nov. 26, 2014
	Decimals	Decimals
Number of criteria emissions established under the Clear Air Act	6
Frequency of Review by Environmental Protection Agency	5 years
Public Utilities, Government Standard Emission Limit	75
Accrual for Environmental Loss Contingencies	0.6
Four Corners Coal Plant Participants
Public Utilities, Assessed Coal Severance Surtax Penalty and Interest	30
Four Corners Generating Station
Date participation is ceased	6-Jul-16
Public Utilities, Assessed Coal Severance Surtax Penalty and Interest	1.5
Minimum
Public Utilities, Government Standard Emission Limit	65	60
Mercury and Air Toxics Standards Required Compliance Period, in Years	3 years
Maximum
Public Utilities, Government Standard Emission Limit	70

Commitments_Contingencies_and_4

Commitments, Contingencies and Uncertainties (Future Minimum Payments For Operating Leases) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Leased Assets [Line Items]
Operating Leases, Rent Expense	$1,800,000	$1,200,000	$1,300,000
2015	1,386,000
2016	838,000
2017	623,000
2018	512,000
2019	$516,000
Newman Land Lease
Operating Leased Assets [Line Items]
Lease Expiration Date	30-Jun-33
Lessee Leasing Arrangements, Operating Leases, Renewal Term	25 years
Warehouse Facilities
Operating Leased Assets [Line Items]
Lease Expiration Date	31-Dec-15
Other Property
Operating Leased Assets [Line Items]
Lessee Leasing Arrangements, Operating Leases, Term of Contract	P3Y

Employee_Benefits_Obligations_

Employee Benefits (Obligations and Funded Status of the Plan) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Retirement Income Plan
Change in projected benefit obligation:
Benefit obligation at end of prior year	$317,815		$320,846
Service cost	8,284		9,137		8,530
Interest cost	14,001		12,742		12,594
Amendments	33,700	[1]	0	[1]
Actuarial (gain) loss	50,741		-15,373
Benefits paid	-16,008		-9,537
Benefit obligation at end of year	341,133		317,815		320,846
Change in plan assets:
Fair value of plan assets at end of prior year	257,831		220,568
Actual return on plan assets	22,116		31,800
Employer contribution	9,000		15,000
Benefits paid	-16,008		-9,537
Fair value of plan assets at end of year	272,939		257,831		220,568
Funded status at end of year	-68,194		-59,984
Other Pension Plans
Change in projected benefit obligation:
Benefit obligation at end of prior year	25,898		27,241
Service cost	303		190		299
Interest cost	1,041		872		963
Amendments	500	[1]	0	[1]
Actuarial (gain) loss	3,508		-533
Benefits paid	-1,853		-1,872
Benefit obligation at end of year	28,397		25,898		27,241
Change in plan assets:
Fair value of plan assets at end of prior year	0		0
Actual return on plan assets	0		0
Employer contribution	1,853		1,872
Benefits paid	-1,853		-1,872
Fair value of plan assets at end of year	0		0		0
Funded status at end of year	($28,397)		($25,898)

[1]	Amendments relate to the modification of the Companybs Retirement Plan and Excess Benefit Plan discussed above.

Employee_Benefits_Defined_Bene

Employee Benefits (Defined Benefit Plan, Amounts Recognized in Balance Sheet) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
Retirement Income Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Current liabilities	$0	$0
Noncurrent liabilities	-68,194,000	-59,984,000
Total	-68,194,000	-59,984,000
Other Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Current liabilities	-2,319,000	-1,870,000
Noncurrent liabilities	-26,078,000	-24,028,000
Total	-28,397,000	-25,898,000
Other Postretirement Benefit Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Current liabilities	0	0
Noncurrent liabilities	-59,342,000	-50,655,000
Total	($59,342,000)	($50,655,000)

Employee_Benefits_Accumulated_

Employee Benefits (Accumulated Benefit Obligations in Excess of Fair Value of Plan Assets) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Retirement Income Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Projected benefit obligation	($341,133)	($317,815)
Accumulated benefit obligation	-312,762	-275,555
Fair value of plan assets	272,939	257,831
Other Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Projected benefit obligation	-28,397	-25,898
Accumulated benefit obligation	-27,603	-25,077
Fair value of plan assets	$0	$0

Employee_Benefits_Amounts_Reco

Employee Benefits (Amounts Recognized in Accumulated Other Comprehensive Income (Loss)) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Retirement Income Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net loss	$124,407	$85,261
Prior service cost (benefit)	-30,811	0
Total	93,596	85,261
Other Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net loss	11,341	8,508
Prior service cost (benefit)	-264	219
Total	$11,077	$8,727

Employee_Benefits_WeightedAver

Employee Benefits (Weighted-Average Actuarial Assumptions for Benefit Obligations - Retirement Plans) (Details)	0 Months Ended	12 Months Ended
	Feb. 28, 2014	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Remeasurement Date	28-Feb-14
Retirement Income Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	4.60%	4.00%	4.90%
Rate of compensation increase		4.50%	4.75%
Supplemental Employee Retirement Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate		3.40%	3.90%
Excess Benefit Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	4.50%	4.10%	4.90%
Rate of compensation increase		4.50%	4.75%
Retirement Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Effect of One Percentage Point Increase on Discount Rate		1.00%
Defined Benefit Plan, Decrease in Projected Benefit Obiligation, Percentage		11.70%
Defined Benefit Plan, Effect of One Percentage Point Decrease on Discount Rate		1.00%
Defined Benefit Plan, Increase in Projected Benefit Obiligation, Percentage		14.60%

Employee_Benefits_Net_Periodic

Employee Benefits (Net Periodic Benefit Costs) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Retirement Income Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$8,284	$9,137	$8,530
Interest cost	14,001	12,742	12,594
Expected return on plan assets	-18,699	-17,108	-14,443
Amortization of:
Net loss	8,178	10,437	10,729
Prior service cost (benefit)	-2,889	3	21
Net periodic benefit cost	8,875	15,211	17,431
Other Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	303	190	299
Interest cost	1,041	872	963
Expected return on plan assets	0	0	0
Amortization of:
Net loss	675	661	627
Prior service cost (benefit)	-17	94	94
Net periodic benefit cost	$2,002	$1,817	$1,983

Employee_Benefits_Other_Compre

Employee Benefits (Other Comprehensive Income - Retirement Plans) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net (gain) loss	$54,328	($82,964)	$2,109
Prior service benefit	-34,200	-97	0
Amortization of:
Net loss	-6,182	-10,472	-11,971
Prior service benefit (cost)	7,659	5,560	5,762
Retirement Income Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net (gain) loss	47,324	-30,065	6,672
Prior service benefit	-33,700	0	0
Amortization of:
Net loss	-8,178	-10,437	-10,729
Prior service benefit (cost)	2,889	-3	-21
Total recognized in other comprehensive income	8,335	-40,505	-4,078
Other Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net (gain) loss	3,508	-533	1,337
Prior service benefit	-500	0	0
Amortization of:
Net loss	-675	-661	-627
Prior service benefit (cost)	17	-94	-94
Total recognized in other comprehensive income	$2,350	($1,288)	$616

Employee_Benefits_Recognized_i

Employee Benefits (Recognized in Other Comprehensive Income and Net Periodic Benefit Costs - Retirement Plans) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Retirement Income Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total recognized in net periodic benefit cost and other comprehensive income	$17,210	($25,294)	$13,353
Other Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total recognized in net periodic benefit cost and other comprehensive income	$4,352	$529	$2,599

Employee_Benefits_Accumulated_1

Employee Benefits (Accumulated Other Comprehensive Income Recognized in Net Periodic Benefit Cost in Next Fiscal Year) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Retirement Income Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net loss/gain	$10,220
Prior service benefit	-3,470
Other Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net loss/gain	850
Prior service benefit	-40
Other Postretirement Benefit Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net loss/gain	2,000
Prior service benefit	$3,100

Employee_Benefits_Weighted_Ave

Employee Benefits (Weighted Average Assumptions Used to Calculate Net Period Benefit Costs- Retirement Plans) (Details)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013	Dec. 31, 2012
Retirement Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected long-term return on plan assets	7.50%
Net Periodic Benefit Costs \| Retirement Income Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	4.90%	[1]	4.00%	4.30%
Expected long-term return on plan assets	7.50%	[1]	7.50%	7.50%
Rate of compensation increase	4.75%	[1]	4.75%	5.00%
Net Periodic Benefit Costs \| Supplemental Employee Retirement Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	3.90%	[1]	3.10%	3.60%
Net Periodic Benefit Costs \| Excess Benefit Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	4.90%	[1]	4.00%	4.10%
Rate of compensation increase	4.75%	[1]	4.75%	5.00%

[1]	The Retirement Plan and the Excess Benefit Plan were remeasured on February 28, 2014 due to the above mentioned plan amendment. The discount rate used to remeasure the benefit obligation was 4.6% for the Retirement Plan and 4.5% for the Excess Benefit Plan, compared to 4.9% for both plans as of January 1, 2014. All other assumptions remained consistent with assumptions used at January 1, 2014.

Employee_Benefits_Target_Asset

Employee Benefits (Target Asset Allocation of Pension Fund) (Details) (Retirement Income Plan)	12 Months Ended
	Dec. 31, 2014
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Assets, Target Allocations Total	100.00%
Equity Securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Assets, Target Allocations	55.00%
Fixed Income
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Assets, Target Allocations	40.00%
Alternative Investments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Assets, Target Allocations	5.00%

Employee_Benefits_Fair_Value_M

Employee Benefits (Fair Value Measurement Inputs) (Details) (Retirement Income Plan, USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Restriction Period To Sell Partnership Interest Minimum	5 years
Restriction Period To Sell Partnership Interest Maximum	7 years
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases, Sales, Issuances, Settlements	$0		$0
Fair value of plan assets at end of year	272,939,000		257,831,000		220,568,000
Cash and Cash Equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year	1,237,000		940,000
Common Collective Trusts
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year	262,954,000	[1]	246,908,000	[1]
Guaranteed Investment Contracts
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year			1,126,000
Limited Partnership Interest in Real Estate
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year	8,748,000	[2]	8,857,000	[2]	8,559,000
Fair Value, Inputs, Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year	1,237,000		940,000
Fair Value, Inputs, Level 1 \| Cash and Cash Equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year	1,237,000		940,000
Fair Value, Inputs, Level 1 \| Common Collective Trusts
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year	0	[1]	0	[1]
Fair Value, Inputs, Level 1 \| Guaranteed Investment Contracts
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year			0
Fair Value, Inputs, Level 1 \| Limited Partnership Interest in Real Estate
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year	0	[2]	0	[2]
Fair Value, Inputs, Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year	262,954,000		248,034,000
Fair Value, Inputs, Level 2 \| Cash and Cash Equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year	0		0
Fair Value, Inputs, Level 2 \| Common Collective Trusts
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year	262,954,000	[1]	246,908,000	[1]
Fair Value, Inputs, Level 2 \| Guaranteed Investment Contracts
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year			1,126,000
Fair Value, Inputs, Level 2 \| Limited Partnership Interest in Real Estate
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year	0	[2]	0	[2]
Fair Value, Inputs, Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year	8,748,000		8,857,000
Fair Value, Inputs, Level 3 \| Cash and Cash Equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year	0		0
Fair Value, Inputs, Level 3 \| Common Collective Trusts
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year	0	[1]	0	[1]
Fair Value, Inputs, Level 3 \| Guaranteed Investment Contracts
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year			0
Fair Value, Inputs, Level 3 \| Limited Partnership Interest in Real Estate
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year	8,748,000	[2]	8,857,000	[2]
Common Collective Trusts \| Equity Funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year	149,839,000	[1]	142,960,000	[1]
Common Collective Trusts \| Fixed Income Funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year	113,115,000	[1]	103,948,000	[1]
Common Collective Trusts \| Fair Value, Inputs, Level 1 \| Equity Funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year	0	[1]	0	[1]
Common Collective Trusts \| Fair Value, Inputs, Level 1 \| Fixed Income Funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year	0	[1]	0	[1]
Common Collective Trusts \| Fair Value, Inputs, Level 2 \| Equity Funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year	149,839,000	[1]	142,960,000	[1]
Common Collective Trusts \| Fair Value, Inputs, Level 2 \| Fixed Income Funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year	113,115,000	[1]	103,948,000	[1]
Common Collective Trusts \| Fair Value, Inputs, Level 3 \| Equity Funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year	0	[1]	0	[1]
Common Collective Trusts \| Fair Value, Inputs, Level 3 \| Fixed Income Funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of year	$0	[1]	$0	[1]

[1]	The Common Collective Trusts are invested in equity or fixed income securities, or a combination thereof. The investment objective of each trust is to produce returns in excess of, or commensurate with, its predefined index.
[2]	This investment is a commercial real estate partnership that purchases land, develops limited infrastructure, and sells it for commercial development. The Company is restricted from selling its partnership interest during the life of the partnership which is generally 5-7 years. Return on investment is realized as land is sold. The fair value of the limited partnership interest in real estate is based on the NAV of the partnership which reflects the appraised value of the land.

Employee_Benefits_Fair_Value_C

Employee Benefits (Fair Value Change in Investment in Real Estate) (Details) (Retirement Income Plan, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of prior year					$220,568
Fair value of plan assets at end of year	272,939		257,831		220,568
Limited Partnership Interest in Real Estate
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of prior year	8,857	[1]	8,559
Sale of Land	-357
Unrealized gain in fair value	248		298
Fair value of plan assets at end of year	$8,748	[1]	$8,857	[1]

[1]	This investment is a commercial real estate partnership that purchases land, develops limited infrastructure, and sells it for commercial development. The Company is restricted from selling its partnership interest during the life of the partnership which is generally 5-7 years. Return on investment is realized as land is sold. The fair value of the limited partnership interest in real estate is based on the NAV of the partnership which reflects the appraised value of the land.

Employee_Benefits_Expected_Fut

Employee Benefits (Expected Future Benefit Payments) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Retirement Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	$11,300
Retirement Income Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
2015	15,776
2016	17,153
2017	17,778
2018	20,019
2019	19,500
2020-2024	103,703
Other Pension Plans
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
2015	2,319
2016	2,248
2017	2,171
2018	2,196
2019	2,135
2020-2024	$10,720

Employee_Benefits_Changes_in_F

Employee Benefits (Changes in Funded Status of Plan - Other Postretirment Benefit Plans) (Details) (Other Postretirement Benefit Plan, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013		Dec. 31, 2012
Other Postretirement Benefit Plan
Change in projected benefit obligation:
Benefit obligation at end of prior year	$92,847	$135,680
Service cost	2,845	3,843		4,378
Interest cost	4,463	5,156		5,651
Actuarial loss (gain)	3,465	-48,778
Amendment	0	-97	[1]
Benefits paid	-4,031	-4,013
Retiree contributions	1,111	1,056
Benefit obligation at end of year	100,700	92,847		135,680
Change in plan assets:
Fair value of plan assets at end of prior year	42,192	36,510
Actual return on plan assets	2,086	5,539
Employer contribution	0	3,100
Benefits paid	-4,031	-4,013
Retiree contributions	1,111	1,056
Fair value of plan assets at end of year	41,358	42,192		36,510
Funded status at end of year	($59,342)	($50,655)
Defined Benefit Plan Amendment Effective Date		3-Oct-13

[1]	Amendment relates to modification of the Company's Other Post-retirement Benefit Plan which limits the Company's premium contribution. The amendment became effective OctoberB 3, 2013 and resulted in a remeasurement of the plan.

Employee_Benefits_Components_o

Employee Benefits (Components of Accumulated Other Comprehensive Income) (Details) (Other Postretirement Benefit Plan, USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Other Postretirement Benefit Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net (gain) loss	($31,943)	($38,110)
Prior service cost (benefit)	-14,457	-19,210
Total	($46,400)	($57,320)

Employee_Benefits_Weighted_Ave1

Employee Benefits (Weighted Average Assumptions- Accrued Postretirement Benefits - Other Postretirment Benefit Plans) (Details) (Other Postretirement Benefit Plan)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Measurement Date		3-Oct-13
Initial	7.50%
Ultimate	4.50%
Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation, Percentage	13.50%
Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation, Percentage	17.20%
Accrued Postretirement Benefit
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	4.10%	4.90%
Initial	7.25%	7.50%
Ultimate	4.50%	4.50%
Year ultimate reached	2026	2026
Defined Benefit Plan, Effect of One Percentage Point Increase on Discount Rate	1.00%
Defined Benefit Plan, Effect of One Percentage Point Decrease on Discount Rate	1.00%

Employee_Benefits_Net_Periodic1

Employee Benefits (Net Periodic Benefit Cost) (Details) (Other Postretirement Benefit Plan, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Postretirement Benefit Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$2,845	$3,843	$4,378
Interest cost	4,463	5,156	5,651
Expected return on plan assets	-2,116	-1,951	-1,714
Prior service benefit	-4,753	-5,657	-5,877
Net (gain) loss	-2,671	-626	615
Net periodic benefit cost	($2,232)	$765	$3,053

Employee_Benefits_Other_Compre1

Employee Benefits (Other Comprehensive Income, Other Postretirement Benefit Plans) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net (gain) loss	$54,328	($82,964)	$2,109
Prior service benefit, arising during period	-34,200	-97	0
Prior service benefit	7,659	5,560	5,762
Net gain (loss)	-6,182	-10,472	-11,971
Other Postretirement Benefit Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Net (gain) loss	3,496	-52,366	-5,900
Prior service benefit, arising during period	0	-97	0
Prior service benefit	4,753	5,657	5,877
Net gain (loss)	2,671	626	-615
Total recognized in other comprehensive income	$10,920	($46,180)	($638)

Employee_Benefits_Recognized_N

Employee Benefits (Recognized Net Periodic Benefit Costs and Other Comprehensive Income -Other Postretirement Benefit Plans) (Details) (Other Postretirement Benefit Plan, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Postretirement Benefit Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total recognized in net periodic benefit cost and other comprehensive income	$8,688	($45,415)	$2,415

Employee_Benefits_Weighted_Ave2

Employee Benefits (Weighted Average Assumptions - Net Periodic Benefit Cost) (Details) (Other Postretirement Benefit Plan, USD $)	3 Months Ended		12 Months Ended	9 Months Ended		12 Months Ended
In Millions, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2014	Oct. 02, 2013		Dec. 31, 2013		Dec. 31, 2012
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate	4.90%
Expected long-term return on plan assets			5.20%
Initial			7.50%
Ultimate			4.50%
Defined Benefit Plan, One Percentage Point Change, Increase or Decrease			1.00%
Defined Benefit Plan, Effect of One Percentage Point Increase on Benefit Obligations			$16.10
Defined Benefit Plan, Effect of One Percentage Point Increase on Service and Interest Cost Components			1.4
Defined Benefit Plan, Effect of One Percentage Point Decrease on Benefit Obligations			12.9
Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components			$1.10
Net Periodic Benefit Costs
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Discount rate			4.90%	4.10%	[1]			4.30%
Expected long-term return on plan assets			5.20%			5.20%	[1]	5.20%
Initial			7.50%			7.75%	[1]	8.00%
Ultimate			4.50%			4.50%	[1]	4.50%
Year ultimate reached	2026	[1]	2026			2026	[1]	2026

[1]	The Other Post-retirement Benefits Plan was remeasured at OctoberB 3, 2013 due to a plan amendment. The discount rate increased from 4.1% as of January 1, 2013 to 4.9% at the remeasurement date. All other assumptions remained consistent with assumptions used at January 1, 2013.

Employee_Benefits_Target_Alloc

Employee Benefits (Target Allocations - Other Postretirment Benefit Plans) (Details) (Other Postretirement Benefit Plan)	12 Months Ended
	Dec. 31, 2014
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Assets, Target Allocations Total	100.00%
Equity Securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Assets, Target Allocations	65.00%
Fixed Income
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Assets, Target Allocations	30.00%
Alternative Investments
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Assets, Target Allocations	5.00%

Employee_Benefits_Fair_Value_M1

Employee Benefits (Fair Value Measurements- Other Postretirement Benefits) (Details) (Other Postretirement Benefit Plan, USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Restriction Period To Sell Partnership Interest Minimum	5 years
Restriction Period To Sell Partnership Interest Maximum	7 years
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases, Sales, Issuances, Settlements	$0
Defined Benefit Plan, Fair Value of Plan Assets	41,358,000		42,192,000		36,510,000
Cash and Cash Equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	1,100,000		33,000
Common Collective Trusts
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	38,618,000	[1]	40,498,000	[1]
Limited Partnership Interest in Real Estate
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	1,640,000	[2]	1,661,000	[2]	1,605,000
Fair Value, Inputs, Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	1,100,000		33,000
Fair Value, Inputs, Level 1 \| Cash and Cash Equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	1,100,000		33,000
Fair Value, Inputs, Level 1 \| Common Collective Trusts
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[1]	0	[1]
Fair Value, Inputs, Level 1 \| Limited Partnership Interest in Real Estate
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[2]	0	[2]
Fair Value, Inputs, Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	38,618,000		40,498,000
Fair Value, Inputs, Level 2 \| Cash and Cash Equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Fair Value, Inputs, Level 2 \| Common Collective Trusts
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	38,618,000	[1]	40,498,000	[1]
Fair Value, Inputs, Level 2 \| Limited Partnership Interest in Real Estate
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[2]	0	[2]
Fair Value, Inputs, Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	1,640,000		1,661,000
Fair Value, Inputs, Level 3 \| Cash and Cash Equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0		0
Fair Value, Inputs, Level 3 \| Common Collective Trusts
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[1]	0	[1]
Fair Value, Inputs, Level 3 \| Limited Partnership Interest in Real Estate
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	1,640,000	[2]	1,661,000	[2]
Common Collective Trusts \| Equity Funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	26,399,000	[1]	28,077,000	[1]
Common Collective Trusts \| Fixed Income Funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	12,219,000	[1]	12,421,000	[1]
Common Collective Trusts \| Fair Value, Inputs, Level 1 \| Equity Funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[1]	0	[1]
Common Collective Trusts \| Fair Value, Inputs, Level 1 \| Fixed Income Funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[1]	0	[1]
Common Collective Trusts \| Fair Value, Inputs, Level 2 \| Equity Funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	26,399,000	[1]	28,077,000	[1]
Common Collective Trusts \| Fair Value, Inputs, Level 2 \| Fixed Income Funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	12,219,000	[1]	12,421,000	[1]
Common Collective Trusts \| Fair Value, Inputs, Level 3 \| Equity Funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	[1]	0	[1]
Common Collective Trusts \| Fair Value, Inputs, Level 3 \| Fixed Income Funds
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$0	[1]	$0	[1]

[1]	The Common Collective Trusts are invested in equity or fixed income securities, or a combination thereof. The investment objective of each trust is to produce returns in excess of, or commensurate with, its predefined index.
[2]	This investment is a commercial real estate partnership that purchases land, develops limited infrastructure, and sells it for commercial development. The Company is restricted from selling its partnership interest during the life of the partnership which is generally 5-7 years. Return of investment is realized as land is sold. The fair value of the limited partnership interest in real estate is based on the NAV of the partnership which reflects the appraised value of the land.

Employee_Benefits_Changes_in_F1

Employee Benefits (Changes in Fair Value Investment Real Estate - Other Postretirement Benefit Plans) (Details) (Other Postretirement Benefit Plan, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of prior year					$36,510
Fair value of plan assets at end of year	41,358		42,192		36,510
Limited Partnership Interest in Real Estate
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of prior year	1,661	[1]	1,605
Unrealized gain in fair value	46		56
Sale of Land	-67
Fair value of plan assets at end of year	$1,640	[1]	$1,661	[1]

[1]	This investment is a commercial real estate partnership that purchases land, develops limited infrastructure, and sells it for commercial development. The Company is restricted from selling its partnership interest during the life of the partnership which is generally 5-7 years. Return of investment is realized as land is sold. The fair value of the limited partnership interest in real estate is based on the NAV of the partnership which reflects the appraised value of the land.

Employee_Benefits_Expected_Fut1

Employee Benefits (Expected Future Benefit Payments - Other Postretirement Benefit Plans) (Details) (Other Postretirement Benefit Plan, USD $)	Dec. 31, 2014
In Thousands, unless otherwise specified	Dec. 31, 2014
Other Postretirement Benefit Plan
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
2015	$3,163
2016	3,528
2017	3,906
2018	4,303
2019	4,570
2020-2024	$27,362

Employee_Benefits_Employee_Ben1

Employee Benefits Employee Benefits (Details) (USD $)	0 Months Ended		12 Months Ended			0 Months Ended
In Millions, unless otherwise specified	Apr. 02, 2014	Feb. 28, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Mar. 31, 2014
Employee Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Number of Non-Qualified Retirement Plans			2
Defined benefit plans revisions effective date	1-Apr-14
Short Term Incentive Plan Payout			$7.40	$4	$7.90
Defined Benefit Plan, Remeasurement Date		28-Feb-14
Retirement Plans
Employee Benefit Plans and Other Postretirement Benefit Plans [Line Items]
Defined benefit plans revisions effective date	1-Apr-14
Pension benefit earned by employee is frozen, date.						31-Mar-14

Employee_Benefits_401k_Defined

Employee Benefits 401(k) Defined Contribution Plans (Details) (USD $)	0 Months Ended	12 Months Ended
In Millions, unless otherwise specified	Apr. 02, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Contribution Plan Disclosure [Line Items]
Defined benefit plans revisions effective date	1-Apr-14
Defined Contribution Plan, Employer Discretionary Contribution Amount		$3	$1.90	$1.80
Defined Contribution Plan, Employer Matching Contribution, Percent of Match	100.00%	50.00%
Maximum
Defined Contribution Plan Disclosure [Line Items]
Defined Contribution Plan, Employer Matching Contribution, Percent	6.00%	6.00%

Franchises_and_Significant_Cus2

Franchises and Significant Customers Franchises and Significant Customers (Details)	12 Months Ended		6 Months Ended
	Dec. 31, 2014		Dec. 31, 2014
Franchises and Significant Customers [Line Items]
Percentage of Revenue Additional Franchise Fees, Restricted	0.75%
Las Cruces
Franchises and Significant Customers [Line Items]
Retail Electric Service Contract, Expiration Date	4/30/09
Fort Bliss
Franchises and Significant Customers [Line Items]
Contract Term to Provide Retail Electric Service			3 years
Holloman
Franchises and Significant Customers [Line Items]
Retail Electric Service Contract, Expiration Date	Jan-16
Contract Term to Provide Retail Electric Service	10 years
August 1, 2010 through Present \| El Paso
Franchises and Significant Customers [Line Items]
Franchise Fee, Percent	4.00%	[1],[2]
February 1, 2000 through Present \| Las Cruces
Franchises and Significant Customers [Line Items]
Franchise Fee, Percent	2.00%	[1]
Sales Revenue, Services, Net \| Military Bases
Franchises and Significant Customers [Line Items]
Concentration Risk, Percentage	5.00%

[1]	Based on a percentage of revenue.
[2]	0.75% of the El Paso franchise fee is to be placed in a restricted fund to be used solely for economic development and renewable energy purposes.

Financial_Instruments_and_Inve1

Financial Instruments and Investments (Carrying Amount and Fair Value Amounts) (Details) (USD $)	Dec. 31, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Carrying (Reported) Amount, Fair Value Disclosure
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure	$1,163,711		$1,013,972
Carrying (Reported) Amount, Fair Value Disclosure \| Pollution Control Bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure	193,135		193,135
Carrying (Reported) Amount, Fair Value Disclosure \| Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure	846,044		696,485
Carrying (Reported) Amount, Fair Value Disclosure \| RGRT Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure	110,000	[1]	110,000	[1]
Carrying (Reported) Amount, Fair Value Disclosure \| Revolving Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure	14,532	[1]	14,352	[1]
Estimate of Fair Value Measurement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure	1,313,558		1,058,707
Estimate of Fair Value Measurement \| Pollution Control Bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure	213,083		193,990
Estimate of Fair Value Measurement \| Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure	968,728		734,515
Estimate of Fair Value Measurement \| RGRT Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure	117,215	[1]	115,850	[1]
Estimate of Fair Value Measurement \| Revolving Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure	$14,532	[1]	$14,352	[1]

[1]	Nuclear fuel financing as of DecemberB 31, 2014 and DecemberB 31, 2013 is funded through the $110 million RGRT Senior Notes and $14.5 million and $14.4 million, respectively under the RCF. As of DecemberB 31, 2014 and 2013, no amount was outstanding under the RCF for working capital or general corporate purposes. The interest rate on the Companybs borrowings under the RCF is reset throughout the period reflecting current market rates. Consequently, the carrying value approximates fair value.

Recovered_Sheet2

Financial Instruments And Investments (Long-Term Debt And Short-Term Borrowings - Narratives) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Aug. 18, 2010	1-May-05
Financial Instruments and Investments [Line Items]
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	$500,000
Decommissioning Fund Investments	234,286,000	214,095,000
Nuclear Fuel Financing
Financial Instruments and Investments [Line Items]
Line of Credit Facility, Amount Outstanding	14,500,000	14,400,000
Working Capital and General Purpose
Financial Instruments and Investments [Line Items]
Line of Credit Facility, Amount Outstanding	0	0
RGRT Senior Notes
Financial Instruments and Investments [Line Items]
Debt Instrument, Face Amount			110,000,000
Senior Notes \| 6.00% Senior Notes, Net of Discount, due 2035
Financial Instruments and Investments [Line Items]
Debt Instrument, Face Amount				$400,000,000
Debt Instrument, Interest Rate, Stated Percentage	6.00%	6.00%		6.00%

Financial_Instruments_And_Inve2

Financial Instruments And Investments (Marketable Securities Fair Value And Unrealized Losses) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
	securities	securities
Financial Instruments and Investments [Line Items]
Marketable Securities Fair Value, Less than 12 Months	$34,651	$32,433
Marketable Securities Unrealized Losses Less Than 12 Months	-1,141	-971
Marketable Securities Fair Value 12 Months or Longer	33,474	20,970
Marketable Securities Unrealized Losses 12 Months or Longer	-1,151	-1,492
Marketable Securities Fair Value, Total	68,125	53,403
Marketable Securities Unrealized Losses, Total	-2,292	-2,463
Number of securities	106	122
Debt Securities
Financial Instruments and Investments [Line Items]
Marketable Securities Fair Value, Less than 12 Months	10,440	30,128
Marketable Securities Unrealized Losses Less Than 12 Months	-91	-845
Marketable Securities Fair Value 12 Months or Longer	33,474	20,970
Marketable Securities Unrealized Losses 12 Months or Longer	-1,151	-1,492
Marketable Securities Fair Value, Total	43,914	51,098
Marketable Securities Unrealized Losses, Total	-1,242	-2,337
Collateralized Mortgage Backed Securities
Financial Instruments and Investments [Line Items]
Marketable Securities Fair Value, Less than 12 Months	0	6,444
Marketable Securities Unrealized Losses Less Than 12 Months	0	-169
Marketable Securities Fair Value 12 Months or Longer	2,383	1,421
Marketable Securities Unrealized Losses 12 Months or Longer	-57	-119
Marketable Securities Fair Value, Total	2,383	7,865
Marketable Securities Unrealized Losses, Total	-57	-288
U.S. Government Bonds
Financial Instruments and Investments [Line Items]
Marketable Securities Fair Value, Less than 12 Months	1,552	8,114
Marketable Securities Unrealized Losses Less Than 12 Months	-2	-245
Marketable Securities Fair Value 12 Months or Longer	20,060	10,866
Marketable Securities Unrealized Losses 12 Months or Longer	-573	-840
Marketable Securities Fair Value, Total	21,612	18,980
Marketable Securities Unrealized Losses, Total	-575	-1,085
Municipal Bonds
Financial Instruments and Investments [Line Items]
Marketable Securities Fair Value, Less than 12 Months	6,433	12,286
Marketable Securities Unrealized Losses Less Than 12 Months	-65	-335
Marketable Securities Fair Value 12 Months or Longer	8,570	7,782
Marketable Securities Unrealized Losses 12 Months or Longer	-410	-479
Marketable Securities Fair Value, Total	15,003	20,068
Marketable Securities Unrealized Losses, Total	-475	-814
Corporate Debt Securities
Financial Instruments and Investments [Line Items]
Marketable Securities Fair Value, Less than 12 Months	2,455	3,284
Marketable Securities Unrealized Losses Less Than 12 Months	-24	-96
Marketable Securities Fair Value 12 Months or Longer	2,461	901
Marketable Securities Unrealized Losses 12 Months or Longer	-111	-54
Marketable Securities Fair Value, Total	4,916	4,185
Marketable Securities Unrealized Losses, Total	-135	-150
Equity Securities
Financial Instruments and Investments [Line Items]
Marketable Securities Fair Value, Less than 12 Months	1,475	2,305
Marketable Securities Unrealized Losses Less Than 12 Months	-229	-126
Marketable Securities Fair Value 12 Months or Longer	0	0
Marketable Securities Unrealized Losses 12 Months or Longer	0	0
Marketable Securities Fair Value, Total	1,475	2,305
Marketable Securities Unrealized Losses, Total	-229	-126
Common Collective Trust - Equity Funds
Financial Instruments and Investments [Line Items]
Marketable Securities Fair Value, Less than 12 Months	22,736
Marketable Securities Unrealized Losses Less Than 12 Months	-821
Marketable Securities Fair Value 12 Months or Longer	0
Marketable Securities Unrealized Losses 12 Months or Longer	0
Marketable Securities Fair Value, Total	22,736
Marketable Securities Unrealized Losses, Total	($821)

Financial_Instruments_And_Inve3

Financial Instruments And Investments (Unrecognized Gross Unrealized Gains And The Fair Value) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	$166,161	$160,692
Available-for-sale Securities, Gross Unrealized Gain	50,930	47,741
Debt Securities
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	60,808	34,158
Available-for-sale Securities, Gross Unrealized Gain	2,677	1,515
Collateralized Mortgage Backed Securities
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	15,388	9,929
Available-for-sale Securities, Gross Unrealized Gain	665	433
U.S. Government Bonds
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	20,016	6,258
Available-for-sale Securities, Gross Unrealized Gain	567	126
Municipal Bonds
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	11,642	8,783
Available-for-sale Securities, Gross Unrealized Gain	595	450
Corporate Debt Securities
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	13,762	9,188
Available-for-sale Securities, Gross Unrealized Gain	850	506
Equity Securities
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	99,160	103,808
Available-for-sale Securities, Gross Unrealized Gain	48,253	43,145
Equity Mutual Funds
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	0	16,802
Available-for-sale Securities, Gross Unrealized Gain	0	3,081
Cash and Cash Equivalents
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	6,193	5,924
Available-for-sale Securities, Gross Unrealized Gain	$0	$0

Financial_Instruments_And_Inve4

Financial Instruments And Investments (Contractual Year For Maturity Of Available-For-Sale Securities ) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items]
Contractual Maturity Due For, Mortgaged Backed Securities	10 years
Municipal Bonds
Schedule of Available-for-sale Securities [Line Items]
Total	26,645
2015	1,011
2016 through 2019	11,318
2020 through 2024	12,967
2025 and Beyond	1,349
Corporate Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Total	18,678
2015	720
2016 through 2019	5,163
2020 through 2024	6,517
2025 and Beyond	6,278
U.S. Government Bonds
Schedule of Available-for-sale Securities [Line Items]
Total	41,628
2015	3,050
2016 through 2019	17,520
2020 through 2024	12,062
2025 and Beyond	8,996
Maximum
Schedule of Available-for-sale Securities [Line Items]
Debt Instrument, Expected Weighted Average Maturity Year	6 years
Minimum
Schedule of Available-for-sale Securities [Line Items]
Debt Instrument, Expected Weighted Average Maturity Year	2 years

Financial_Instruments_And_Inve5

Financial Instruments And Investments (Unrealized Holding Losses Included In Pre-Tax Income) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Financial Instruments And Investments [Abstract]
Unrealized losses included in pre-tax income	$0	$0	($479)

Financial_Instruments_And_Inve6

Financial Instruments And Investments (Sale Of Securities And The Related Effects On Pre-Tax Income ) (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Investment [Line Items]
Proceeds from sales of available-for-sale securities	$108,311	$56,148	$98,542
Gross realized gains included in pre-tax income	7,858	986	1,478
Gross realized losses included in pre-tax income	-508	-433	-2,041
Other than Temporary Impairment Losses, Investments, Recognized in Earnings, before Tax, Available-for-sale Securities	0	0	-479
Net unrealized holding gains (losses) included in accumulated other comprehensive income	10,827	17,699	9,927
Net gains (losses) in pre-tax income	-7,350	-553	1,042
Net gains (losses) in other comprehensive income	$3,477	$17,146	$10,969

Financial_Instruments_And_Inve7

Financial Instruments And Investments (Company's Decommissioning Trust Funds And Investments In Debt Securities) (Details) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Decommisioning Fund Investments
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	$234,286	$214,095
Decommisioning Fund Investments \| Quoted Prices In Active Markets For Identical Assets (Level 1)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	148,456	154,077
Decommisioning Fund Investments \| Significant Other Observable Inputs (Level 2)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	85,830	60,018
Decommisioning Fund Investments \| Significant Unobservable Inputs (Level 3)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	0	0
Debt Securities
Financial Instruments and Investments [Line Items]
Investments in Debt Securities	1,653	1,555	1,295
Debt Securities \| Quoted Prices In Active Markets For Identical Assets (Level 1)
Financial Instruments and Investments [Line Items]
Investments in Debt Securities	0	0
Debt Securities \| Significant Other Observable Inputs (Level 2)
Financial Instruments and Investments [Line Items]
Investments in Debt Securities	0	0
Debt Securities \| Significant Unobservable Inputs (Level 3)
Financial Instruments and Investments [Line Items]
Investments in Debt Securities	1,653	1,555
Debt Securities \| Decommisioning Fund Investments
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	104,722	85,256
Debt Securities \| Decommisioning Fund Investments \| Quoted Prices In Active Markets For Identical Assets (Level 1)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	41,628	25,238
Debt Securities \| Decommisioning Fund Investments \| Significant Other Observable Inputs (Level 2)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	63,094	60,018
Debt Securities \| Decommisioning Fund Investments \| Significant Unobservable Inputs (Level 3)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	0	0
U.S. Government Bonds \| Decommisioning Fund Investments
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	41,628	25,238
U.S. Government Bonds \| Decommisioning Fund Investments \| Quoted Prices In Active Markets For Identical Assets (Level 1)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	41,628	25,238
U.S. Government Bonds \| Decommisioning Fund Investments \| Significant Other Observable Inputs (Level 2)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	0	0
U.S. Government Bonds \| Decommisioning Fund Investments \| Significant Unobservable Inputs (Level 3)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	0	0
Collateralized Mortgage Backed Securities \| Decommisioning Fund Investments
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	17,771	17,794
Collateralized Mortgage Backed Securities \| Decommisioning Fund Investments \| Quoted Prices In Active Markets For Identical Assets (Level 1)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	0	0
Collateralized Mortgage Backed Securities \| Decommisioning Fund Investments \| Significant Other Observable Inputs (Level 2)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	17,771	17,794
Collateralized Mortgage Backed Securities \| Decommisioning Fund Investments \| Significant Unobservable Inputs (Level 3)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	0	0
Municipal Bonds \| Decommisioning Fund Investments
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	26,645	28,851
Municipal Bonds \| Decommisioning Fund Investments \| Quoted Prices In Active Markets For Identical Assets (Level 1)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	0	0
Municipal Bonds \| Decommisioning Fund Investments \| Significant Other Observable Inputs (Level 2)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	26,645	28,851
Municipal Bonds \| Decommisioning Fund Investments \| Significant Unobservable Inputs (Level 3)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	0	0
Corporate Debt Securities \| Decommisioning Fund Investments
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	18,678	13,373
Corporate Debt Securities \| Decommisioning Fund Investments \| Quoted Prices In Active Markets For Identical Assets (Level 1)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	0	0
Corporate Debt Securities \| Decommisioning Fund Investments \| Significant Other Observable Inputs (Level 2)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	18,678	13,373
Corporate Debt Securities \| Decommisioning Fund Investments \| Significant Unobservable Inputs (Level 3)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	0	0
Equity Securities \| Decommisioning Fund Investments
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	100,635	106,113
Equity Securities \| Decommisioning Fund Investments \| Quoted Prices In Active Markets For Identical Assets (Level 1)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	100,635	106,113
Equity Securities \| Decommisioning Fund Investments \| Significant Other Observable Inputs (Level 2)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	0	0
Equity Securities \| Decommisioning Fund Investments \| Significant Unobservable Inputs (Level 3)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	0	0
Common Collective Trust - Equity Funds \| Decommisioning Fund Investments
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	22,736
Common Collective Trust - Equity Funds \| Decommisioning Fund Investments \| Quoted Prices In Active Markets For Identical Assets (Level 1)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	0
Common Collective Trust - Equity Funds \| Decommisioning Fund Investments \| Significant Other Observable Inputs (Level 2)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	22,736
Common Collective Trust - Equity Funds \| Decommisioning Fund Investments \| Significant Unobservable Inputs (Level 3)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	0
Equity Mutual Funds \| Decommisioning Fund Investments
Financial Instruments and Investments [Line Items]
Available-for-sale Securities		16,802
Equity Mutual Funds \| Decommisioning Fund Investments \| Quoted Prices In Active Markets For Identical Assets (Level 1)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities		16,802
Equity Mutual Funds \| Decommisioning Fund Investments \| Significant Other Observable Inputs (Level 2)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities		0
Equity Mutual Funds \| Decommisioning Fund Investments \| Significant Unobservable Inputs (Level 3)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities		0
Cash and Cash Equivalents \| Decommisioning Fund Investments
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	6,193	5,924
Cash and Cash Equivalents \| Decommisioning Fund Investments \| Quoted Prices In Active Markets For Identical Assets (Level 1)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	6,193	5,924
Cash and Cash Equivalents \| Decommisioning Fund Investments \| Significant Other Observable Inputs (Level 2)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	0	0
Cash and Cash Equivalents \| Decommisioning Fund Investments \| Significant Unobservable Inputs (Level 3)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	$0	$0

Recovered_Sheet3

Financial Instruments and Investments (Reconciliation) (Details) (Debt Securities, USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Debt Securities
Fair Value in Investment in Debt Securities [Roll Forward]
Balance at January 1	$1,555		$1,295
Net unrealized gains (losses) in fair value recognized in income on debt securities still held	98	[1]	260	[1]
Balance at December 31	$1,653		$1,555

[1]	These amounts are reflected in the Company's statement of operations as investment and interest income.

Supplemental_Statements_of_Cas2

Supplemental Statements of Cash Flows Disclosures Supplemental Statements of Cash Flows Disclosures (Details) (USD $)	12 Months Ended
In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Supplemental Cash Flow Information [Abstract]
Interest on long-term debt and borrowing under the revolving credit facility	$54,792	$53,752	$50,189
Income taxes, net of refund	6,876	244	5,031
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock issued	3,025	3,224	2,411
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock issued	$0	$849	$1,193

Selected_Quarterly_Financial_D2

Selected Quarterly Financial Data (Unaudited) Selected Quarterly Financial Data (Unaudited) (Details) (USD $)	3 Months Ended																12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2014		Sep. 30, 2014		Jun. 30, 2014		Mar. 31, 2014		Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Selected Quarterly Financial Data
Operating revenues	$196,563	[1]	$283,645	[1]	$251,801	[1]	$185,516	[1]	$190,297	[1]	$282,661	[1]	$240,114	[1]	$177,290	[1]	$917,525	$890,362	$852,881
Operating income	8,871		81,496		51,131		9,665		6,050		85,896		54,344		19,345		151,163	165,635	168,658
Net income	$4,241		$52,476		$30,096		$4,615		$1,191		$50,565		$29,193		$7,634		$91,428	$88,583	$90,846
Basic earnings per share:
Net income	$0.10		$1.30		$0.75		$0.11		$0.03		$1.26		$0.73		$0.19		$2.27	$2.20	$2.27
Diluted earnings per share:
Net income	$0.10		$1.30		$0.75		$0.11		$0.03		$1.26		$0.72		$0.19		$2.27	$2.20	$2.26
Dividends declared per share of common stock	$0.28		$0.28		$0.28		$0.27		$0.27		$0.27		$0.27		$0.25		$1.10	$1.04	$0.97

[1]	Operating revenues are seasonal in nature, with the peak sales periods generally occurring during the summer months. Comparisons among quarters of a year may not represent overall trends and changes in operations.