El Paso Electric 10-Q 5 Aug 16 2016 Q2 Quarterly report Financial data

Document And Entity Information

Document And Entity Information - shares	6 Months Ended
	Jun. 30, 2016	Jul. 31, 2016
Document and Entity Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2016
Document Fiscal Year Focus	2,016
Document Fiscal Period Focus	Q2
Trading Symbol	ee
Entity Registrant Name	EL PASO ELECTRIC CO /TX/
Entity Central Index Key	31,978
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		40,520,871

Balance Sheets

Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Utility plant:
Electric plant in service	$ 3,783,907	$ 3,616,301
Less accumulated depreciation and amortization	(1,369,646)	(1,329,843)
Net plant in service	2,414,261	2,286,458
Construction work in progress	221,607	293,796
Nuclear fuel; includes fuel in process of $54,224 and $51,854, respectively	191,925	190,282
Less accumulated amortization	(75,546)	(75,031)
Net nuclear fuel	116,379	115,251
Net utility plant	2,752,247	2,695,505
Current assets:
Cash and cash equivalents	9,607	8,149
Accounts receivable, principally trade, net of allowance for doubtful accounts of $1,570 and $2,046, respectively	105,443	66,326
Inventories, at cost	47,376	48,697
Under-collection of fuel revenues	30	0
Prepayments and other	15,062	9,872
Total current assets	177,518	133,044
Deferred charges and other assets:
Decommissioning trust funds	248,240	239,035
Regulatory assets	116,617	115,127
Other	17,640	17,896
Total deferred charges and other assets	382,497	372,058
Total assets	3,312,262	3,200,607
Capitalization:
Common stock, stated value $1 per share, 100,000,000 shares authorized, 65,670,835 and 65,709,819 shares issued, and 157,520 and 118,834 restricted shares, respectively	65,828	65,829
Capital in excess of stated value	320,572	320,073
Retained earnings	1,059,398	1,067,396
Accumulated other comprehensive loss, net of tax	(13,300)	(13,914)
Total stockholders equity subtotal before treasury stock	1,432,498	1,439,384
Treasury stock, 25,307,484 and 25,384,834 shares, respectively, at cost	(421,558)	(422,846)
Common stock equity	1,010,940	1,016,538
Long-term debt, net of current portion	1,278,301	1,122,660
Total capitalization	2,289,241	2,139,198
Current liabilities:
Short-term borrowings under the revolving credit facility	101,614	141,738
Accounts payable, principally trade	44,162	59,978
Taxes accrued	25,318	30,351
Interest accrued	13,267	12,649
Over-collection of fuel revenues	2,063	4,023
Other	41,950	28,325
Total current liabilities	228,374	277,064
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	502,677	495,237
Accrued pension liability	87,728	90,527
Accrued post-retirement benefit liability	55,677	54,553
Asset retirement obligation	85,363	81,621
Regulatory liabilities	23,930	24,303
Other	39,272	38,104
Total deferred credits and other liabilities	794,647	784,345
Commitments and contingencies
Total capitalization and liabilities	$ 3,312,262	$ 3,200,607

Balance Sheets Parenthetical

Balance Sheets Parenthetical - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Nuclear fuel; fuel in process	$ 54,224	$ 51,854
Allowance for Doubtful Accounts Receivable, Current	$ 1,570	$ 2,046
Common Stock, Par or Stated Value Per Share	$ 1	$ 1
Common Stock, Shares Authorized	100,000,000	100,000,000
Common Stock, Shares, Issued	65,670,835	65,709,819
Common stock, restricted shares	157,520	118,834
Treasury Stock, Shares	25,307,484	25,384,834

Statements Of Operations

Statements Of Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Operating revenues	$ 217,865	$ 219,508	$ 375,674	$ 383,254	$ 842,289	$ 863,462
Energy expenses:
Fuel	43,143	49,813	77,462	87,542	178,320	217,289
Purchased and interchanged power	13,610	11,742	23,256	22,917	53,884	51,678
Cost of services, energy services	56,753	61,555	100,718	110,459	232,204	268,967
Operating revenues net of energy expenses	161,112	157,953	274,956	272,795	610,085	594,495
Other operating expenses:
Other operations	56,817	57,656	115,204	113,255	244,899	235,664
Maintenance	20,426	19,857	37,941	35,417	67,747	70,819
Depreciation and amortization	23,852	23,135	47,145	44,700	92,269	86,391
Taxes other than income taxes	15,320	15,433	30,132	29,591	64,277	61,422
Utilities operating expense	116,415	116,081	230,422	222,963	469,192	454,296
Operating income	44,697	41,872	44,534	49,832	140,893	140,199
Other income (deductions):
Allowance for equity funds used during construction	2,133	2,268	4,469	6,543	8,565	14,838
Investment and interest income, net	3,591	1,398	6,520	6,652	17,376	14,121
Miscellaneous non-operating income	145	507	801	687	2,176	2,655
Miscellaneous non-operating deductions	(890)	(1,271)	(1,356)	(1,762)	(3,922)	(4,943)
Nonoperating income (expense)	4,979	2,902	10,434	12,120	24,195	26,671
Interest charges (credits):
Interest on long-term debt and revolving credit facility	18,298	16,495	34,897	32,978	67,770	62,820
Other interest	272	354	834	517	1,630	1,306
Capitalized interest	(1,253)	(1,261)	(2,495)	(2,550)	(4,913)	(5,115)
Allowance for borrowed funds used during construction	(1,375)	(1,391)	(3,033)	(4,012)	(5,958)	(8,729)
Interest expense	15,942	14,197	30,203	26,933	58,529	50,282
Income before income taxes	33,734	30,577	24,765	35,019	106,559	116,588
Income tax expense	11,450	9,505	8,289	10,489	32,695	35,341
Net income	$ 22,284	$ 21,072	$ 16,476	$ 24,530	$ 73,864	$ 81,247
Basic earnings per share	$ 0.550	$ 0.520	$ 0.410	$ 0.610	$ 1.830	$ 2.010
Diluted earnings per share	0.550	0.520	0.410	0.610	1.830	2.010
Dividends declared per share of common stock	$ 0.310	$ 0.295	$ 0.605	$ 0.575	$ 1.195	$ 1.135
Weighted average number of shares outstanding	40,345,150	40,269,885	40,335,236	40,256,615	40,314,032	40,236,466
Weighted average number of shares and dilutive potential shares outstanding	40,399,491	40,302,694	40,380,640	40,284,757	40,356,239	40,263,304

Statements Of Comprehensive Ope

Statements Of Comprehensive Operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Net income	$ 22,284	$ 21,072	$ 16,476	$ 24,530	$ 73,864	$ 81,247
Unrecognized pension and post-retirement benefit costs:
Net gain (loss) arising during period	0	0	0	0	5,429	(74,028)
Prior service benefit	0	0	0	0	824	34,200
Reclassification adjustments included in net income for amortization of:
Prior service benefit	(1,664)	(1,662)	(3,330)	(3,325)	(6,579)	(7,455)
Net loss	1,222	2,250	2,445	4,500	6,567	7,730
Net unrealized gains/losses on marketable securities:
Net holding gains (losses) arising during period	2,790	(1,563)	4,980	(549)	2,623	3,210
Reclassification adjustments for net (gains) losses included in net income	(2,110)	182	(3,498)	(3,563)	(11,049)	(7,946)
Net losses on cash flow hedges:
Reclassification adjustment for interest expense included in net income	123	116	245	230	482	452
Total other comprehensive income (loss) before income taxes	361	(677)	842	(2,707)	(1,703)	(43,837)
Income tax benefit (expense) related to items of other comprehensive income (loss):
Unrecognized pension and post-retirement benefit costs	166	(291)	222	(622)	(2,442)	14,761
Net unrealized losses (gains) on marketable securities	(149)	325	(322)	881	1,625	979
Losses on cash flow hedges	(46)	(43)	(128)	(115)	(216)	(197)
Total income tax benefit (expense)	(29)	(9)	(228)	144	(1,033)	15,543
Other comprehensive income (loss), net of tax	332	(686)	614	(2,563)	(2,736)	(28,294)
Comprehensive income	$ 22,616	$ 20,386	$ 17,090	$ 21,967	$ 71,128	$ 52,953

Statements Of Cash Flows

Statements Of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash flows from operating activities:
Net income	$ 16,476	$ 24,530
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization of electric plant in service	47,145	44,700
Amortization of nuclear fuel	21,957	21,379
Deferred income taxes, net	6,695	8,789
Allowance for equity funds used during construction	(4,469)	(6,543)
Other amortization and accretion	8,715	8,888
Gain on sale of land	(545)	0
Net gains on sale of decommissioning trust funds	(3,498)	(3,563)
Other operating activities	721	243
Change in:
Accounts receivable	(39,117)	(20,782)
Inventories	1,315	(2,813)
Net over-collection (under-collection) of fuel revenues	(1,990)	10,833
Prepayments and other	(6,273)	(7,476)
Accounts payable	(9,345)	(15,528)
Taxes accrued	(5,437)	(2,990)
Interest accrued	618	107
Other current liabilities	13,625	2,669
Deferred charges and credits	(5,900)	(2,068)
Net cash provided by operating activities	40,693	60,375
Cash flows from investing activities:
Cash additions to utility property, plant and equipment	(102,785)	(147,040)
Cash additions to nuclear fuel	(20,478)	(22,424)
Capitalized interest and AFUDC:
Utility property, plant and equipment	(7,502)	(10,555)
Nuclear fuel	(2,495)	(2,550)
Allowance for equity funds used during construction	4,469	6,543
Decommissioning trust funds:
Purchases, including funding of $2.2 million and $2.3 million, respectively	(44,937)	(41,029)
Sales and maturities	40,712	37,158
Proceeds from sale of land	596	0
Other investing activities	2,771	82
Net cash used for investing activities	(129,649)	(179,815)
Cash flows from financing activities:
Dividends paid	(24,474)	(23,220)
Borrowings under the revolving credit facility:
Proceeds	172,125	167,103
Payments	(212,249)	(53,563)
Proceeds from issuance of senior notes	157,052	0
Other financing activities	(2,040)	(1,020)
Net cash provided by financing activities	90,414	89,300
Net increase (decrease) in cash and cash equivalents	1,458	(30,140)
Cash and cash equivalents at beginning of period	8,149	40,504
Cash and cash equivalents at end of period	$ 9,607	$ 10,364

Statements Of Cash Flows Parent

Statements Of Cash Flows Parenthetical - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Payments To Fund Decommissioning Fund	$ 2.2	$ 2.3

Principles Of Preparation

Principles Of Preparation	6 Months Ended
	Jun. 30, 2016
Accounting Policies [Abstract]
Principles Of Preparation	Principles of Preparation These condensed financial statements should be read in conjunction with the financial statements and notes thereto in the Annual Report of El Paso Electric Company on Form 10-K for the fiscal year ended December 31, 2015 (the " 2015 Form 10-K"). Capitalized terms used in this report and not defined herein have the meaning ascribed to such terms in the 2015 Form 10-K. In the opinion of the Company’s management, the accompanying financial statements contain all adjustments necessary to present fairly the financial position of the Company at June 30, 2016 and December 31, 2015 ; the results of its operations and comprehensive operations for the three, six and twelve months ended June 30, 2016 and 2015 ; and its cash flows for the six months ended June 30, 2016 and 2015 . The results of operations and comprehensive operations for the three and six months ended June 30, 2016 and the cash flows for the six months ended June 30, 2016 are not necessarily indicative of the results to be expected for the full calendar year. Pursuant to the rules and regulations of the Securities and Exchange Commission (the "SEC"), certain financial information has been condensed and certain footnote disclosures have been omitted. Such information and disclosures are normally included in financial statements prepared in accordance with generally accepted accounting principles. 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. The Company evaluates its estimates on an on-going basis, including those related to depreciation, unbilled revenue, income taxes, fuel costs, pension and other post-retirement obligations and asset retirement obligations ("ARO"). Actual results could differ from those estimates. Revenues . Revenues related to the sale of electricity are generally recorded when service is provided 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 recorded for estimated amounts of energy delivered in the period following the customer's billing cycle to the end of 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 $36.5 million at June 30, 2016 and $21.7 million at December 31, 2015 . The Company presents revenues net of sales taxes in its statements of operations. Supplemental Cash Flow Disclosures (in thousands) Six Months Ended June 30, 2016 2015 Cash paid (received) for: Interest on long-term debt and borrowings under the revolving credit facility $ 35,252 $ 30,922 Income tax paid, net 2,703 1,680 Non-cash investing and financing activities: Changes in accrued plant additions (6,966 ) (1,227 ) Grants of restricted shares of common stock 1,236 1,106 New Accounting Standards. In April 2015, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2015-03, Interest - Imputation of Interest (Topic 715) to simplify the presentation of debt issuance costs. ASU 2015-03 requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by this ASU. ASU 2015-03 is effective for financial statements issued for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. In August 2015, the FASB issued ASU 2015-15, Interest - Imputation of Interest (Subtopic 835-30), to provide further clarification to ASU 2015-03 as it relates to the presentation and subsequent measurement of debt issuance costs associated with line of credit arrangements. The Company implemented ASU 2015-03 and ASU 2015-15 in the first quarter of 2016, retrospectively to all prior periods presented in the Company's financial statements. The implementation of ASU 2015-03 did not have a material impact on the Company's results of operations. See Note J. In May 2015, the FASB issued ASU 2015-07, Fair Value Measurement (Topic 820) to eliminate the requirement to categorize investments in the fair value hierarchy if the fair value is measured at net asset value ("NAV") per share (or its equivalent) using the practical expedient in the FASB’s fair value measurement gui dance . Reporting entities must still provide sufficient information to enable users to reconcile total investments in the fair value hierarchy and total investments measured at fair value in the financial statements. Additionally, the scope of current disclosure requirements for investments eligible to be measured at NAV will be limited to investments to which the practical expedient is applied. This ASU is effective in fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. The ASU requires retrospective application. The Company implemented ASU 2015-07 in the first quarter of 2016, retrospectively to all prior periods presented in the Company's fair value disclosures. This guidance required a revision of the fair value disclosures but did not impact the Company's financial statements. The implementation of ASU 2015-07 did not have a material impact on the Company's results of operations. See Note J. In November 2015, the FASB issued ASU 2015-17, Balance Sheet Classification of Deferred Taxes to simplify the presentation of deferred income taxes. ASU 2015-17 requires that deferred tax liabilities and assets be classified as noncurrent in a classified statement of financial position. ASU 2015-17 can be applied prospectively or retrospectively and is effective for financial statements issued for annual periods beginning after December 15, 2016 and interim periods within those annual periods and early adoption is permitted . The Company elected to early adopt ASU 2015-17 retrospectively in the first quarter of 2016. The implementation of ASU 2015-17 did not have a material impact on the Company's results of operations. See Note F. In May 2014, the FASB issued 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 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 was originally intended to be effective for annual periods and interim periods within that reporting period beginning after December 15, 2016, for public business entities. In August 2015, FASB issued ASU 2015-14 to defer the effective date of ASU 2014-09 for all entities by one year. Public business entities will apply the guidance in ASU 2014-09 to annual reporting periods beginning after December 15, 2017 and interim periods within that reporting period. In March 2016, the FASB issued ASU 2016-08 to clarify the implementation guidance on principal versus agent consideration. In April 2016, the FASB issued ASU 2016-10 to clarify the implementation guidance on identifying performance obligations and licensing. In May 2016, the FASB issued ASU 2016-11, which rescinds certain SEC Staff Observer comments that are codified in FASB ASC Topic 605 (Revenue Recognition), effective upon adoption of Topic 606. In May 2016, the FASB issued ASU 2016-12, which makes narrow-scope amendments to ASU 2014-09, and provides practical expedients to simplify the transition to the new standard and to clarify certain aspects of the standard. Early adoption of ASU 2014-09 is permitted after December 15, 2016. The Company has not selected a transition method and is currently assessing the future impact of this ASU. In January 2016, the FASB issued ASU 2016-01, Financial Instruments-Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Liabilities to enhance the reporting model for financial instruments by addressing certain aspects of recognition, measurement, presentation, and disclosure. ASU 2016-01 generally requires entities to measure equity investments that do not result in consolidation and are not accounted for under the equity method at fair value and recognize any changes in fair value in net income. The guidance for classifying and measuring investments in debt securities and loans is not changed by this ASU, but requires entities to record changes in other comprehensive income. Financial assets and financial liabilities must be separately presented by measurement category on the balance sheet or in the accompanying notes to the financial statements. ASU 2016-01 clarifies the need for a valuation allowance on a deferred tax asset related to available-for-sale securities in combination with the entity's other deferred tax assets. The standard includes a requirement that businesses must report changes in the fair value of their own liabilities in other comprehensive income instead of earnings, and this is the only provision of the update for which the FASB is permitting early adoption. The remaining provisions of this ASU become effective for public companies for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The Company is currently assessing the future impact of this ASU. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and requiring qualitative and quantitative disclosures on leasing agreements. ASU 2016-02 maintains a distinction between finance leases and operating leases similar to the distinction under previous leases guidance for capital leases and operating leases. The impact of leases reported in the Company's operating results and statement of cash flows are expected to be similar to previous GAAP. ASU 2016-02 requires the recognition in the statement of financial position, by the lessee, of a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. How leases are recorded in regard to financial position represents a significant change from previous GAAP. The lessee is permitted to make an accounting policy election to not recognize lease assets and lease liabilities for short-term leases. Implementation of the standard for public companies will be required for annual reporting periods beginning after December 15, 2018 and interim periods within that reporting period. Early adoption of ASU 2016-02 is permitted for all entities. Adoption of the new lease accounting standard will require the Company to apply the new standard to the earliest period using a modified retrospective approach. The Company is currently assessing the future impact of this ASU. In March 2016, the FASB issued ASU 2016-09, Compensation – Stock Compensation (Topic 718) Improvements to Employee Share-Based Payment Accounting to simplify the accounting for share-based payment transactions, including the income tax consequences, classification of awards either as equity or liabilities, and classification on the statements of cash flows. This ASU is effective for annual periods beginning after December 15, 2016, and interim periods within those annual periods. Early adoption is permitted. The Company is currently assessing the future impact of this ASU. In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326). ASU 2016-13 significantly changes how companies measure and recognize credit impairment for many financial assets. The new current expected credit loss model will require companies to immediately recognize an estimate of credit losses expected to occur over the remaining life of the financial assets that are in the scope of the standard. The ASU also makes targeted amendments to the current impairment model for available-for-sale debt securities. For public business entities, the provisions of ASU 2016-13 are effective for fiscal years and interim periods within that reporting period beginning after December 15, 2019. Early implementation is permitted as of the fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. ASU 2016-13 will be applied in a modified-retrospective approach through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is implemented. The Company is currently assessing the future impact of this ASU. Reclassification. Certain amounts in the financial statements for 2015 have been reclassified to conform to the 2016 presentation. The Company implemented ASU 2015-03 and ASU 2015-17 in the first quarter of 2016, retrospectively to all periods presented in the Company's financial statements. See Note J and Note F, respectively.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Notes)	6 Months Ended
	Jun. 30, 2016
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): Three Months Ended June 30, 2016 Three Months Ended June 30, 2015 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) 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 beginning of period $ (30,256 ) $ 28,394 $ (11,770 ) $ (13,632 ) $ (34,628 ) $ 36,782 $ (12,032 ) $ (9,878 ) Other comprehensive income (loss) before reclassifications — 2,224 — 2,224 — (1,191 ) — (1,191 ) Amounts reclassified from accumulated other comprehensive income (loss) (276 ) (1,693 ) 77 (1,892 ) 297 135 73 505 Balance at end of period $ (30,532 ) $ 28,925 $ (11,693 ) $ (13,300 ) $ (34,331 ) $ 35,726 $ (11,959 ) $ (10,564 ) Six Months Ended June 30, 2016 Six Months Ended June 30, 2015 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) 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 beginning of period $ (29,869 ) $ 27,765 $ (11,810 ) $ (13,914 ) $ (34,884 ) $ 38,957 $ (12,074 ) $ (8,001 ) Other comprehensive income (loss) before reclassifications — 3,966 — 3,966 — (369 ) — (369 ) Amounts reclassified from accumulated other comprehensive income (loss) (663 ) (2,806 ) 117 (3,352 ) 553 (2,862 ) 115 (2,194 ) Balance at end of period $ (30,532 ) $ 28,925 $ (11,693 ) $ (13,300 ) $ (34,331 ) $ 35,726 $ (11,959 ) $ (10,564 ) Twelve Months Ended June 30, 2016 Twelve Months Ended June 30, 2015 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) 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 beginning of period $ (34,331 ) $ 35,726 $ (11,959 ) $ (10,564 ) $ (9,539 ) $ 39,483 $ (12,214 ) $ 17,730 Other comprehensive income (loss) before reclassifications 3,777 2,080 — 5,857 (24,775 ) 2,681 — (22,094 ) Amounts reclassified from accumulated other comprehensive income (loss) 22 (8,881 ) 266 (8,593 ) (17 ) (6,438 ) 255 (6,200 ) Balance at end of period $ (30,532 ) $ 28,925 $ (11,693 ) $ (13,300 ) $ (34,331 ) $ 35,726 $ (11,959 ) $ (10,564 ) Amounts reclassified from accumulated other comprehensive income (loss) for the three, six and twelve months ended June 30, 2016 and 2015 are as follows (in thousands): Details about Accumulated Other Comprehensive Income (Loss) Components Three Months Ended June 30, Six Months Ended June 30, Twelve Months Ended June 30, Affected Line Item in the Statement of Operations 2016 2015 2016 2015 2016 2015 Amortization of pension and post-retirement benefit costs: Prior service benefit $ 1,664 $ 1,662 $ 3,330 $ 3,325 $ 6,579 $ 7,455 (a) Net loss (1,222 ) (2,250 ) (2,445 ) (4,500 ) (6,567 ) (7,730 ) (a) 442 (588 ) 885 (1,175 ) 12 (275 ) (a) Income tax effect (166 ) 291 (222 ) 622 (34 ) 292 Income tax expense 276 (297 ) 663 (553 ) (22 ) 17 (a) Marketable securities: Net realized gain (loss) on sale of securities 2,110 (182 ) 3,498 3,563 11,049 7,946 Investment and interest income, net 2,110 (182 ) 3,498 3,563 11,049 7,946 Income before income taxes Income tax effect (417 ) 47 (692 ) (701 ) (2,168 ) (1,508 ) Income tax expense 1,693 (135 ) 2,806 2,862 8,881 6,438 Net income Loss on cash flow hedge: Amortization of loss (123 ) (116 ) (245 ) (230 ) (482 ) (452 ) Interest on long-term debt and revolving credit facility (123 ) (116 ) (245 ) (230 ) (482 ) (452 ) Income before income taxes Income tax effect 46 43 128 115 216 197 Income tax expense (77 ) (73 ) (117 ) (115 ) (266 ) (255 ) Net income Total reclassifications $ 1,892 $ (505 ) $ 3,352 $ 2,194 $ 8,593 $ 6,200 (a) These items are included in the computation of net periodic benefit cost. See Note I, Employee Benefits, for additional information.

Regulation

Regulation	6 Months Ended
	Jun. 30, 2016
Public Utilities, General Disclosures [Abstract]
Regulation	Regulation General The rates and services of the Company are regulated by incorporated municipalities in Texas, the Public Utility Commission of Texas ("PUCT"), the New Mexico Public Regulation Commission ("NMPRC"), and the Federal Regulatory Commission ("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 the 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. 2015 Texas Retail Rate Case Filing. On August 10, 2015, the Company filed with the City of El Paso, other municipalities incorporated in its Texas service territory, and the PUCT in Docket No. 44941, a request for an annual increase in non-fuel base revenues of approximately $71.5 million . On January 15, 2016, the Company filed its rebuttal testimony modifying the requested increase to $63.3 million . The Company invoked its statutory right to have its new rates relate back for consumption on and after January 12, 2016, which is the 155 th day after the filing. The difference in rates that would have been billed will be surcharged or refunded to customers after the PUCT's final order in Docket No. 44941. The PUCT has the authority to require the Company to surcharge or refund such difference over a period not to exceed 18 months. On January 21, 2016, the Company, the City of El Paso, the PUCT Staff, the Office of Public Utility Counsel and Texas Industrial Energy Consumers filed a joint motion to abate the procedural schedule to facilitate settlement talks. This motion was granted. On March 29, 2016, the Company and other settling parties to PUCT Docket No. 44941 filed a Non-Unanimous Stipulation and Agreement and motion to approve interim rates (the "Non-Unanimous Settlement") with the PUCT. Four parties to the rate case opposed the Non-Unanimous Settlement but not the interim rates. Interim rates reflecting an annual non-fuel base rate increase of $37 million were approved by the Administrative Law Judges ("ALJs") effective April 1, 2016 subject to refund or surcharge. Subsequent to filing the Non-Unanimous Settlement, the rate case was subject to numerous procedural matters, including a May 19, 2016 ruling by the PUCT that the Company’s initial notice did not adequately contemplate the treatment of residential customers with solar generation contained in the Non-Unanimous Settlement. Settlement discussions continued, and on July 21, 2016, the Company filed a Joint Motion to Implement Uncontested Amended and Restated Stipulation and Agreement with the PUCT, which was unopposed by parties to the rate case in Docket No. 44941 (the "Unopposed Settlement"). The terms of the Unopposed Settlement include: (i) an annual non-fuel base rate increase of $37 million , lower annual depreciation expense of approximately $8.5 million , a return on equity of 9.7% for AFUDC purposes, and including substantially all new plant in service in rate base; (ii) an additional annual non-fuel base rate increase of $3.7 million related to Four Corners Generating Station costs; (iii) removing the separate treatment for residential customers with solar generation; and (iv) allowing the Company to recover most of the rate case expenses up to a date certain. The Unopposed Settlement is subject to approval by the PUCT. The settlement documents were filed with ALJs assigned to oversee the Company's Texas Rate case, who have returned the settled case to the PUCT for approval. It is anticipated that the Unopposed Settlement will be considered by the PUCT at its meeting scheduled for August 18, 2016. The costs of serving residential customers with solar generation will be addressed in a future proceeding. Given the uncertainties regarding the ultimate resolution of this rate case, the Company did not recognize the impacts of the Unopposed Settlement in the Statements of Operations for the second quarter of 2016. The additional revenues resulting from the implementation of the interim rates in the amount of $10.8 million were deferred and included in other current liabilities on the Company's Balance Sheet at June 30, 2016 . At this time, the Company believes the revenue and other impacts of the Unopposed Settlement for financial reporting purposes will be recognized during the second half of 2016. Regardless of the ultimate timing and amounts, new rates will relate back to consumption on and after January 12, 2016. 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. The PUCT approved the Company's request at its November 14, 2014 open meeting. The Company recorded the $2.0 million bonus as operating revenue in the fourth quarter of 2014. On May 1, 2015, the Company made its annual filing to establish its energy efficiency cost recovery factor for 2016. In addition to projected energy efficiency costs for 2016 and a true-up to prior year actual costs, the Company requested approval of a $1.0 million bonus for the 2014 energy efficiency program results in accordance with PUCT rules. This case was assigned PUCT Docket No. 44677. A stipulation and settlement agreement was filed September 24, 2015 and the PUCT approved the settlement on November 5, 2015. The settlement approved by the PUCT includes a performance bonus of $1.0 million . The Company recorded the performance bonus as operating revenue in the fourth quarter of 2015. On April 29, 2016, the Company made its annual filing to establish its energy efficiency cost recovery factor for 2017. In addition to projected energy efficiency costs for 2017 and true-up to prior year actual costs, the Company requested approval of a $668 thousand bonus for the 2015 energy efficiency program results in accordance with PUCT rules. This case was assigned PUCT Docket No. 45855. The Company expects the Commission will make a final decision in the proceeding before the end of 2016. 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, 2015, the Company filed a request, which was assigned PUCT Docket No. 44633, to reduce its fixed fuel factor by approximately 24% to reflect reduced fuel expenses primarily related to a reduction in the price of natural gas used to generate power. The over-recovered balance was below the PUCT's materiality threshold. The reduction in the fixed fuel factor was effective on an interim basis May 1, 2015 and approved by the PUCT on May 20, 2015 . As of June 30, 2016 , the Company had over-recovered fuel costs in the amount of $1.0 million for the Texas jurisdiction. 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 with no significant adjustments. The PUCT's final order completes the regulatory review and reconciliation of the Company's fuel expenses for the period through March 31, 2013. The Company is required to file an application by the end of September 2016 for fuel reconciliation of the Company's fuel expenses for the period through March 31, 2016. Montana Power Station ("MPS") Approvals . T he Company has received a Certificate of Convenience and Necessity ("CCN") from the PUCT to construct four natural gas fired generating units at MPS in El Paso County, Texas. The Company also obtained air permits from the Texas Commission on Environmental Quality (the "TCEQ") and the U.S. Environmental Protection Agency (the "EPA"). MPS Units 1 and 2 and associated transmission lines and common facilities were completed and placed into service in March 2015 . MPS Unit 3 was completed and placed into service on May 3, 2016 . Community Solar. On June 8, 2015, the Company filed a petition with the PUCT to initiate a community solar program to include construction and ownership of a 3 MW solar photovoltaic system located at MPS. Participation will be on a voluntary basis, and customers will contract for a set capacity (kW) amount and receive all energy produced. This case was assigned PUCT Docket No. 44800. The Company filed a settlement agreement among all parties on July 1, 2016 which would approve the program, and the Company expects an order from the PUCT on or about August 18, 2016 approving the settlement agreement. Four Corners Generating Station ("Four Corners"). On February 17, 2015 , the Company and Arizona Public Service Company ("APS") entered into an asset purchase agreement (the "Purchase and Sale Agreement") providing for the purchase by APS of the Company's interests in Four Corners. The Four Corners transaction closed on July 6, 2016 . See Note D for further details on the sale of Four Corners. On June 10, 2015, the Company filed an application in Texas requesting reasonableness and public interest findings and certain rate and accounting findings related to the Purchase and Sale Agreement. This case was assigned PUCT Docket No. 44805. Subsequent to the filing of the application, the case has been subject to numerous procedural matters, including a March 23, 2016 order in which the PUCT determined not to dismiss the reasonableness and public interest issues in this docket but to consider the requested rate and accounting findings, including mine reclamation costs, in the Company's next rate case, which is expected to be filed in early 2017. The procedural schedule related to the public interest issues calls for a hearing to be held on October 6-7, 2016. At June 30, 2016, the regulatory asset associated with mine reclamation costs for our Texas jurisdiction approximated $7.7 million . The Company currently continues to recover its mine reclamation costs in Texas under previous orders and decisions of the PUCT. If any future determinations made by our regulators result in changes to how existing regulatory assets or previously incurred costs for Four Corners are recovered in rates, any such changes would be recognized only when it becomes probable future cash flows will change as a result of such regulatory actions. Other Required Approvals . The Company has obtained other required approvals for 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 are updated annually for adjustment to the recovery factors. 2015 New Mexico Rate Case Filing . On May 11, 2015, the Company filed with the NMPRC in Case No. 15-00127-UT, for an annual increase in non-fuel base rates of approximately $8.6 million or 7.1% . The filing also requested an annual reduction of $15.4 million , or 21.5% , for fuel and purchased power costs. Subsequently, the Company reduced its requested increase in non-fuel base rates to approximately $6.4 million . On June 8, 2016, the NMPRC issued its final order approving an annual increase in non-fuel base rates of approximately $1.1 million and a decrease in the Company's allowed return on equity to 9.48% . The final order concludes that all of the Company's plant additions are in service and used and useful, and that the costs were prudently incurred, and therefore would be recoverable and included in rate base. The Company's rates were approved by the NMPRC effective July 1, 2016. Fuel and Purchased Power Costs. On January 8, 2014, the NMPRC approved the continuation of the Fuel and Purchased Power Cost Adjustment Clause (the "FPPCAC") without modification in NMPRC Case No. 13-00380-UT. Historically, fuel and purchased power costs were recovered through base rates and a FPPCAC that accounts for changes in the costs of fuel relative to the amount included in base rates. Effective July 1, 2016, with the implementation of the final order of Case No. 15-00127-UT, fuel and purchase power costs will no longer be recovered through base rates but will be completely recovered through the FPPCAC. 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 costs related to Palo Verde Unit 3 capacity and energy in New Mexico through the FPPCAC as purchased power using a proxy market price approved in Case No. 13-00380-UT. At June 30, 2016 , the Company had a net fuel over-recovery balance of $1.1 million in New Mexico. Montana Power Station Approvals. The Company has received a CCN from the NMPRC to construct four units at MPS and the associated transmission lines. The Company also obtained all necessary air permits from the TCEQ and the EPA. 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. MPS Units 1 and 2 and MPS to Caliente and MPS In & Out transmission lines were completed and placed into service in March 2015 . MPS Unit 3 was completed and placed into service on May 3, 2016 . Four Corners. On February 17, 2015 , the Company and APS entered into the Purchase and Sale Agreement providing for the purchase by APS of the Company's interests in Four Corners. On April 27, 2015, the Company filed an application in NMPRC Case No. 15-00109-UT requesting all necessary regulatory approvals to sell its ownership interest in Four Corners. On February 2, 2016, the Company filed a joint stipulation with the NMPRC reflecting a settlement agreement among the NMPRC's Utility Division Staff, the Company and the New Mexico Attorney General proposing approval of abandonment and sale of its seven percent minority ownership interest in Four Corners Units 4 and 5 and common facilities to APS. An addendum to the joint stipulation was subsequently filed and the joint stipulation was unopposed. A hearing in the case was held on February 16, 2016, and the Hearing Examiner issued a Certification of Stipulation on April 22, 2016 recommending approval of the joint stipulation without modification. On June 15, 2016, the NMPRC issued its final order approving the stipulation. See Note D for further details on the sale of Four Corners. 5 MW Holloman Air Force Base ("HAFB") Facility CCN . On June 15, 2015, the Company filed a petition with the NMPRC requesting CCN authorization to construct a 5 MW solar-powered generation facility to be located at HAFB in the Company's service territory in New Mexico. The new facility will be a dedicated Company-owned resource serving HAFB. This case was assigned NMPRC Case No. 15-00185-UT. On October 7, 2015, the NMPRC issued a final order accepting the Hearing Examiner’s Recommended Decision to approve the CCN, as modified. The Company and HAFB are in discussions for a power sales agreement for the facility to replace the existing load retention agreement. Issuance of Long-Term Debt and Guarantee of Debt. On October 7, 2015, the Company received approval in NMPRC Case No. 15-00280-UT to issue up to $310 million in new long-term debt; and to guarantee the issuance of up to $65 million of new debt by Rio Grande Resources Trust ("RGRT") to finance future purchases of nuclear fuel and to refinance existing nuclear fuel debt obligations. This approval supersedes prior approvals. Under this authorization, on March 24, 2016 , the Company issued $150 million in aggregate principal amount of 5.00% Senior Notes due December 1, 2044 . The net proceeds from the issuance of these senior notes, after deducting the underwriters' commission, were $158.1 million . These proceeds include accrued interest of $2.4 million and a $7.1 million premium before expenses. These senior notes constitute an additional issuance of the Company's 5.00% Senior Notes due 2044 , of which $150 million was previously issued on December 1, 2014 , for a total principal amount outstanding of $300 million . Other Required Approvals . The Company has obtained other required approvals for other tariffs, securities transactions, recovery of energy efficiency costs through a base rate rider and other approvals as required by the NMPRC. Federal Regulatory Matters Four Corners. On June 26, 2015, APS filed an application requesting authorization from FERC to purchase 100% of the Company’s ownership interest in Units 4 and 5 of Four Corners and the associated transmission interconnection facilities and rights. On December 22, 2015, FERC issued an order approving the proposed transaction. The Four Corners transaction closed on July 6, 2016 . See Note D for further details on the sale of Four Corners. Public Service Company of New Mexico ( " 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. On March 20, 2015, PNM filed with FERC a settlement agreement and offer of settlement resolving all issues set for hearing in the proceeding. On March 25, 2015, the Chief Judge issued an order granting PNM's motion to implement the settled rates. On March 17, 2016, FERC issued an order approving the settlement. Revolving Credit Facility; Issuance of Long-Term Debt and Guarantee of Debt. On October 19, 2015, the FERC issued an order in Docket No. ES15-66-000 approving the Company’s filing to issue short-term debt under its existing revolving credit facility ("RCF") up to $400 million outstanding at any time, to issue up to $310 million in long-term debt, and to guarantee the issuance of up to $65 million of new long-term debt by RGRT to finance future nuclear fuel purchases. The authorization is effective from November 15, 2015 through November 15, 2017 . This approval supersedes prior approvals. Under this authorization, on March 24, 2016 , the Company issued $150 million in aggregate principal amount of 5.00% Senior Notes due December 1, 2044 . The net proceeds from the issuance of these senior notes, after deducting the underwriters' commission, were $158.1 million . These proceeds include accrued interest of $2.4 million and a $7.1 million premium before expenses. These senior notes constitute an additional issuance of the Company's 5.00% Senior Notes due 2044 , of which $150 million was previously issued on December 1, 2014 , for a total principal amount outstanding of $300 million . Other Required Approvals. The Company has obtained required approvals for rates and tariffs, securities transactions and other approvals as required by the FERC.

Palo Verde and Four Corners

Palo Verde and Four Corners	6 Months Ended
	Jun. 30, 2016
Palo Verde and Four Corners [Abstract]
Palo Verde and Four Corners	Palo Verde and Four Corners Spent Nuclear Fuel and Waste Disposal. Pursuant to the Nuclear Waste Policy Act of 1982, as amended in 1987 (the "NWPA"), the U.S. Department of Energy (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 Palo Verde Participants, 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 Participants 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 credited to customers through the applicable fuel adjustment clauses. On October 31, 2014 , APS, acting on behalf of itself and the Palo Verde Participants, 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 accepted claim amount was $42.0 million . On June 1, 2015 , the Company received approximately $6.6 million , representing its share of the award. The majority of the award was credited to customers through the applicable fuel adjustment clauses in March 2015. Thereafter APS will file annual claims for the period July 1 of the then-previous year to June 30 of the then-current year. On November 2, 2015 , APS filed a $12.0 million claim for the period July 1, 2014 through June 30, 2015 . In February 2016, the DOE notified APS of the approval of the claim. Funds related to this claim were received in the first quarter of 2016 . The Company's share of this claim is approximately $1.9 million . The majority of the award was credited to customers through the applicable fuel adjustment clauses in March 2016. APS's next claim pursuant to the terms of the August 18, 2014 settlement agreement will be submitted to the DOE in the fourth quarter of 2016, and payment is expected in the second quarter of 2017. Four Corners. On February 17, 2015 , the Company and APS entered into the Purchase and Sale Agreement providing for the purchase by APS of the Company’s interests in Four Corners. Four Corners continued to provide energy to serve the Company's native load up to the closing date, and is classified as held for use in the Company's June 30, 2016 financial statements. The net book value of the utility plant related to Four Corners was $31.9 million at June 30, 2016. Included in the Company's Balance Sheet at June 30, 2016 are obligations of $7.0 million and $19.5 million for plant decommissioning and mine reclamation costs, respectively, which were assumed by APS as part of the sale. The Four Corners transaction closed on July 6, 2016 . The sales price was $32.0 million based on the net book value as defined in the Purchase and Sale Agreement. The sales price was adjusted downward by $7.0 million and $19.5 million , respectively, to reflect APS's assumption of the Company's obligation to pay for future plant decommissioning and mine reclamation expenses. The sales price was also adjusted downward by approximately $1.3 million for closing adjustments and other assets and liabilities assumed by APS. At the closing, the Company received approximately $4.2 million in cash, subject to post-closing adjustments. No significant gain or loss was recorded upon the closing of the sale. APS will assume responsibility for all capital expenditures made after July 6, 2016. In addition, APS will indemnify the Company against liabilities and costs related to the future operation of Four Corners. See Note C for a discussion of regulatory filings associated with Four Corners.

Common Stock

Common Stock	6 Months Ended
	Jun. 30, 2016
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Shareholders' Equity and Share-based Payments, Including Earnings Per Share Information	Common Stock Dividends. The Company paid $12.5 million and $11.9 million in quarterly cash dividends during the three months ended June 30, 2016 and 2015 , respectively. The Company paid a total of $24.5 million and $48.4 million in quarterly cash dividends during the six and twelve months ended June 30, 2016 , respectively. The Company paid a total of $23.2 million and $45.8 million in quarterly cash dividends during the six and twelve months ended June 30, 2015 , respectively. On July 21, 2016 , the Board of Directors declared a quarterly cash dividend of $0.31 per share payable on September 30, 2016 to shareholders of record as of the close of business on September 14, 2016 . Basic and Diluted Earnings Per Share . The basic and diluted earnings per share are presented below (in thousands except for share data): Three Months Ended June 30, 2016 2015 Weighted average number of common shares outstanding: Basic number of common shares outstanding 40,345,150 40,269,885 Dilutive effect of unvested performance awards 54,341 32,809 Diluted number of common shares outstanding 40,399,491 40,302,694 Basic net income per common share: Net income $ 22,284 $ 21,072 Income allocated to participating restricted stock (65 ) (65 ) Net income available to common shareholders $ 22,219 $ 21,007 Diluted net income per common share: Net income $ 22,284 $ 21,072 Income reallocated to participating restricted stock (65 ) (65 ) Net income available to common shareholders $ 22,219 $ 21,007 Basic net income per common share: Distributed earnings $ 0.310 $ 0.295 Undistributed earnings 0.240 0.225 Basic net income per common share $ 0.550 $ 0.520 Diluted net income per common share: Distributed earnings $ 0.310 $ 0.295 Undistributed earnings 0.240 0.225 Diluted net income per common share $ 0.550 $ 0.520 Six Months Ended June 30, 2016 2015 Weighted average number of common shares outstanding: Basic number of common shares outstanding 40,335,236 40,256,615 Dilutive effect of unvested performance awards 45,404 28,142 Diluted number of common shares outstanding 40,380,640 40,284,757 Basic net income per common share: Net income $ 16,476 $ 24,530 Income allocated to participating restricted stock (66 ) (71 ) Net income available to common shareholders $ 16,410 $ 24,459 Diluted net income per common share: Net income $ 16,476 $ 24,530 Income reallocated to participating restricted stock (66 ) (71 ) Net income available to common shareholders $ 16,410 $ 24,459 Basic net income per common share: Distributed earnings $ 0.605 $ 0.575 Undistributed earnings (0.195 ) 0.035 Basic net income per common share $ 0.410 $ 0.610 Diluted net income per common share: Distributed earnings $ 0.605 $ 0.575 Undistributed earnings (0.195 ) 0.035 Diluted net income per common share $ 0.410 $ 0.610 Twelve Months Ended June 30, 2016 2015 Weighted average number of common shares outstanding: Basic number of common shares outstanding 40,314,032 40,236,466 Dilutive effect of unvested performance awards 42,207 26,838 Diluted number of common shares outstanding 40,356,239 40,263,304 Basic net income per common share: Net income $ 73,864 $ 81,247 Income allocated to participating restricted stock (210 ) (253 ) Net income available to common shareholders $ 73,654 $ 80,994 Diluted net income per common share: Net income $ 73,864 $ 81,247 Income reallocated to participating restricted stock (210 ) (253 ) Net income available to common shareholders $ 73,654 $ 80,994 Basic net income per common share: Distributed earnings $ 1.195 $ 1.135 Undistributed earnings 0.635 0.875 Basic net income per common share $ 1.830 $ 2.010 Diluted net income per common share: Distributed earnings $ 1.195 $ 1.135 Undistributed earnings 0.635 0.875 Diluted net income per common share $ 1.830 $ 2.010 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: Three Months Ended Six months ended Twelve Months Ended June 30, June 30, June 30, 2016 2015 2016 2015 2016 2015 Restricted stock awards 42,759 48,669 51,111 58,432 52,714 59,380 Performance shares (a) 62,995 59,898 62,995 59,898 56,089 48,136 (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.

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2016
Components of Income Tax Expense (Benefit), Continuing Operations [Abstract]
Income Taxes	Income Taxes 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 2011 . The Company is currently under audit in Texas for tax years 2007 through 2011 . In June 2016, the Arizona Department of Revenue discontinued their audits for tax years 2009 through 2012 . The discontinuance of the audits did not have a material impact on the Company's results of operations or financial position. For the three months ended June 30, 2016 and 2015 , the Company’s effective tax rate was 33.9% and 31.1% , respectively. For the six months ended June 30, 2016 and 2015 , the Company's effective tax rate was 33.5% and 30.0% , respectively. For the twelve months ended June 30, 2016 and 2015 , the Company's effective tax rate was 30.7% and 30.3% , respectively. The Company's effective tax rate for all periods differs from the federal statutory tax rate of 35.0% primarily due to capital gains in the decommissioning trusts which are taxed at the federal rate of 20.0% , the allowance for equity funds used during construction ("AEFUDC"), and state taxes. In November 2015, the FASB issued new guidance (ASU 2015-17, Balance Sheet Classification of Deferred Taxes) to simplify the presentation of deferred income taxes. ASU 2015-17 requires that deferred tax liabilities and assets be classified as noncurrent in a classified statement of financial position. ASU 2015-17 can be applied prospectively or retrospectively and is effective for financial statements issued for annual periods beginning after December 15, 2016 and interim periods within those annual periods and early adoption is permitted. The Company elected to implement ASU 2015-17 on a retrospective basis for financial statements issued beginning March 31, 2016. The implementation of ASU 2015-17 did not have a material impact on the Company's results of operations. The impact of ASU 2015-17 on the Company's Balance Sheet was to reclassify $21.6 million of current deferred tax assets to long-term deferred tax liabilities at December 31, 2015.

Commitments, Contingencies And

Commitments, Contingencies And Uncertainties	6 Months Ended
	Jun. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Commitments, Contingencies And Uncertainties	Commitments, Contingencies and Uncertainties For a full discussion of commitments and contingencies, see Note K of the Notes to Financial Statements in the 2015 Form 10-K. In addition, see Notes C and D above and Notes C and E of the Notes to Financial Statements in the 2015 Form 10-K regarding matters related to wholesale power sales contracts and transmission contracts subject to regulation and Palo Verde, including decommissioning, spent nuclear fuel and waste disposal, and liability and insurance matters. Power Purchase and Sale Contracts To supplement its own generation and operating reserve requirements, and to meet required renewable portfolio standards, the Company engages in power purchase arrangements which may vary in duration and amount based on an evaluation of the Company's resource needs, the economics of the transactions, and specific renewable portfolio requirements. For a full discussion of power purchase and sale contracts that the Company has entered into with various counterparties, see Note K of the Notes to Financial Statements in the 2015 Form 10-K. 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. For a more detailed discussion of certain key environmental issues, laws, and regulations facing the Company, see Note K of the Notes to Financial Statements in the 2015 Form 10-K. 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 nitrogen oxides ("NOx") and sulfur dioxide ("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, and on October 23, 2014, the D.C Circuit lifted its stay of CSAPR. On July 28, 2015, the D.C. Circuit ruled that the EPA's emissions budgets for 13 states including Texas are invalid, but left the rule in place on remand. On December 3, 2015, EPA published the proposed CSAPR Update Rule. While we are unable to determine the full impact of this decision until EPA takes further action, the Company believes it is currently positioned to comply with CSAPR. National Ambient Air Quality Standards ("NAAQS"). Under the Clean Air Act ("CAA"), the EPA sets NAAQS for six criteria pollutants considered harmful to public health and the environment, including particulate matter ("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 nitrogen dioxide ("NO2") and SO2. The EPA is considering a 1-hour secondary NAAQS for NO2 and SO2. In January 2013, the EPA tightened the NAAQS for fine PM. On October 1, 2015, following on its November 2014 proposal, EPA released a final rule tightening the primary and secondary NAAQS for ground-level ozone from its 2008 standard levels of 75 parts per billion ("ppb") to 70 ppb. 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. The EPA is expected to make attainment/nonattainment designations for the revised ozone standards by October 1, 2017. While it is currently unknown how the areas in which we operate will ultimately be designated, for nonattainment areas classified as "Moderate" and above, states, and any tribes that choose to do so, are expected to be required to complete development of implementation plans in the 2020-2021 timeframe. Most nonattainment areas are expected to have until 2020 or 2023 to meet the primary (health) standard, with the exact attainment date varying based on the ozone level in the area. 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 NAAQS, individually or in the aggregate, could have a material impact on its operations and financial results. Mercury and Air Toxics Standards. 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 "MATS Rule") 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, and on June 29, 2015, the U.S. Supreme Court remanded the rule to the D.C. Circuit Court. On December 15, 2015, the D.C. Circuit Court issued an order remanding the rule to EPA but did not vacate the rule during remand. On April 15, 2016, the EPA completed a cost-benefit analysis of the MATS rule and reaffirmed its finding that the rule is "appropriate and necessary," which will be reviewed by the D.C. Circuit Court. The legal status of the MATS Rule notwithstanding, the Four Corners plant operator, APS, believes Units 4 and 5 will require no additional modifications to achieve compliance with the MATS Rule, as currently written. We cannot currently predict, however, what additional modifications or costs may be incurred if the EPA rewrites the MATS Rule on remand. Other Laws and Regulations and Risks. The Company 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 expects to 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. On June 15, 2016, the Company received a final order containing the required regulatory approval from the NMPRC. On July 6, 2016 , the closing of the transaction occurred, after which the Company no longer owns any coal-fired generation. Coal Combustion Waste. On October 19, 2015, the EPA's final rule regulating the disposal of coal combustion residuals (the “CCR Rule”) from electric utilities as solid waste took effect. The Company had a 7% ownership interest in Units 4 and 5 of Four Corners, the only coal-fired generating facility for which the Company had an ownership interest subject to the CCR Rule. The Company entered into a Purchase and Sale Agreement with APS in February 2015 to sell the Company’s entire ownership interest in Four Corners and closing of the sale occurred on July 6, 2016 . The CCR Rule requires plant owners to treat coal combustion residuals as Subtitle D (as opposed to a more costly Subtitle C) waste. In general, the Company is liable for only 7% of costs to comply with the CCR Rule (consistent with our ownership percentage). The Company, however, believes under the terms of the Purchase Agreement and after the sale, as a former owner, that the Company is not responsible for a significant portion of the costs under the CCR Rule, such as ongoing operational costs after July 2016. Accordingly, the Company does not expect the CCR Rule to have a significant impact on our financial condition or results of operations. On November 3, 2015, the EPA published a final rule revising wastewater effluent limitation guidelines for steam electric power generators (the "Revised ELG Rule"). The Revised ELG Rule establishes requirements for wastewater streams from certain processes at affected facilities, including limits on toxic metals in wastewater discharges. Facilities must comply with the Revised ELG Rule between 2018 and 2023. The EPA anticipates that the new requirements in the Revised ELG Rule will only affect certain coal-fired steam electric power plants. Because the Company does not have an interest in Four Corners after the closing of the sale in July 2016, the Company does not expect the Revised ELG Rule will have a significant impact on our financial condition or results of operations. In 2012, several environmental groups filed a lawsuit in federal district court against the Office of Surface Mining Reclamation and Enforcement ("OSM") of the U.S. Department of the Interior, challenging OSM’s 2012 approval of a permit revision which allowed for the expansion of mining operations into a new area of the mine that serves Four Corners ("Area IV North"). In April 2015, the court issued an order invalidating the permit revision, thereby prohibiting mining in Area IV North until OSM takes action to cure the defect in its permitting process identified by the court. On December 29, 2015, OSM took action to cure the defect in its permitting process by issuing a revised environmental assessment and finding of no new significant impact, and reissued the permit. This action is subject to possible judicial review. On March 30, 2016, the U.S. Court of Appeals vacated and dismissed the federal court decision that halted operations in Area IV North at the Navajo Mine. On April 20, 2016, the same environmental groups filed a new complaint in Arizona's federal district court, challenging multiple permits and approvals issued to both the Navajo Mine and Four Corners authorizing operations from July 2016 onwards. The complaint seeks to enjoin federal agencies, including the OSM and Bureau of Indian Affairs, from authorizing any element of the power plant or mine without further environmental impact analysis. Climate Change. In recent years, there has been increasing public debate regarding the potential impact of global climate change. There has been a wide-ranging policy debate, both nationally and internationally, regarding the impact of GHG and possible means for their regulation. In addition, efforts have been made and continue to be made in the international community toward the adoption of international treaties or protocols that would address global climate change issues. Most recently, in 2015, the United States participated in the United Nations Conference on Climate Change, which led to creation of the Paris Agreement. On April 22, 2016, 175 countries, including the United States, signed the Paris Agreement, signaling their intent to join. Those countries that subsequently ratify the agreement will be required to review and "represent a progression" in their intended nationally determined contributions, which set GHG emission reduction goals, every five years, beginning in 2020. 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 October 2015, the EPA published a final rule establishing new source performance standards ("NSPS") limiting CO2 emissions from new, modified, and reconstructed electric generating units. In October 2015, the EPA also published a rule establishing guidelines for states to regulate CO2 emissions from existing power plants, as well as a proposed "federal plan" to address CO2 emissions from affected units in those states that do not submit an approvable compliance plan. The standards for existing plants are known as the Clean Power Plan ("CPP"), under which rule interim emissions performance rates must be achieved beginning in 2022 and final emissions performance rates by 2030. Legal challenges to the CPP were filed by groups of states and industry members. On February 9, 2016, the U.S. Supreme Court issued a decision to stay the rule until legal issues are resolved. We cannot at this time determine the impact the CPP and related rules and legal challenges may have on our financial position, results of operations, or cash flows.

Litigation

Litigation	6 Months Ended
	Jun. 30, 2016
Litigation [Abstract]
Litigation Matters Disclosure	Litigation The Company is involved in various legal, environmental, tax and regulatory proceedings before various courts, regulatory commissions and governmental agencies regarding matters arising in the ordinary course of business. In many of these matters, the Company has excess casualty liability insurance that covers the various claims, actions and complaints. The Company regularly analyzes current information and, as necessary, makes provisions in its financial statements for probable liabilities for the eventual disposition of these matters. While the outcome of these matters cannot be predicted with certainty, based upon a review of the matters and applicable insurance coverage, the Company believes that none of these matters 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 Notes C and G above and Notes C and K of the Notes to Financial Statements in the 2015 Form 10-K for discussion of the effects of government legislation and regulation on the Company.

Employee Benefits

Employee Benefits	6 Months Ended
	Jun. 30, 2016
General Discussion of Pension and Other Postretirement Benefits [Abstract]
Employee Benefits	Employee Benefits Retirement Plans The net periodic benefit cost recognized for the three, six and twelve months ended June 30, 2016 and 2015 is made up of the components listed below as determined using the projected unit credit actuarial cost method (in thousands): Three Months Ended Six Months Ended Twelve Months Ended June 30, June 30, June 30, 2016 2015 2016 2015 2016 2015 Components of net periodic benefit cost: Service cost $ 1,905 $ 2,100 $ 3,810 $ 4,200 $ 8,402 $ 8,425 Interest cost 3,265 3,625 6,530 7,250 13,775 14,632 Expected return on plan assets (4,713 ) (4,948 ) (9,425 ) (9,895 ) (19,325 ) (19,258 ) Amortization of: Net loss 1,887 2,750 3,775 5,500 8,922 10,065 Prior service benefit (877 ) (887 ) (1,755 ) (1,775 ) (3,486 ) (3,528 ) Net periodic benefit cost $ 1,467 $ 2,640 $ 2,935 $ 5,280 $ 8,288 $ 10,336 During the six months ended June 30, 2016 , the Company contributed $2.8 million of its projected $6.2 million 2016 annual contribution to its retirement plans. Other Postretirement Benefits The net periodic benefit cost recognized for the three, six and twelve months ended June 30, 2016 and 2015 is made up of the components listed below (in thousands): Three Months Ended Six Months Ended Twelve Months Ended June 30, June 30, June 30, 2016 2015 2016 2015 2016 2015 Components of net periodic benefit cost: Service cost $ 715 $ 875 $ 1,430 $ 1,750 $ 3,134 $ 3,173 Interest cost 872 1,025 1,745 2,050 3,730 4,281 Expected return on plan assets (460 ) (525 ) (920 ) (1,050 ) (1,940 ) (2,108 ) Amortization of: Prior service benefit (787 ) (775 ) (1,575 ) (1,550 ) (3,093 ) (3,927 ) Net gain (665 ) (500 ) (1,330 ) (1,000 ) (2,355 ) (2,335 ) Net periodic benefit cost (benefit) $ (325 ) $ 100 $ (650 ) $ 200 $ (524 ) $ (916 ) During the six months ended June 30, 2016 , the Company contributed $1.1 million of its projected $1.7 million 2016 annual contribution to its other post retirement benefits plan.

Financial Instruments And Inves

Financial Instruments And Investments (Notes)	6 Months Ended
	Jun. 30, 2016
Fair Value Disclosures [Abstract]
Financial Instruments and Investments	Financial Instruments and Investments The 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 estimated 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): June 30, 2016 December 31, 2015 Carrying Amount (1) Estimated Fair Value Carrying Amount (1) Estimated Fair Value Pollution Control Bonds $ 190,637 $ 214,132 $ 190,499 $ 212,624 Senior Notes 992,924 1,193,209 837,475 829,864 RGRT Senior Notes (2) 94,740 101,215 94,686 100,345 RCF (2) 101,614 101,614 141,738 141,738 Total $ 1,379,915 $ 1,610,170 $ 1,264,398 $ 1,284,571 _______________ (1) The Company implemented ASU 2015-03, Interest - Imputation of Interest, which requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability. ASU 2015-03 is effective for financial statements issued for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. The impact of ASU 2015-03 on the Company's Balance Sheet was to reclassify $11.6 million of other deferred charges to long-term debt, net of current portion at December 31, 2015. (2) Nuclear fuel financing, as of June 30, 2016 and December 31, 2015 , is funded through the $95 million RGRT Senior Notes and $34.6 million and $33.7 million , respectively under the RCF. As of June 30, 2016 , $67.0 million was outstanding under the RCF for working capital or general corporate purposes. As of December 31, 2015 , $108.0 million 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 quarter reflecting c urrent market rates. Consequently, the carrying value approximates fair value. Marketable Securities. The Company's marketable securities, included in decommissioning trus t funds in the Balance Sheets, are reported at fair value which was $248.2 million and $239.0 million at June 30, 2016 and December 31, 2015 , respectively. These securities are classified as available for sale and recorded at their estimated fair value using the FASB guidance for certain investments in debt and equity 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): June 30, 2016 Less than 12 Months 12 Months or Longer Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Description of Securities (1) : Federal Agency Mortgage Backed Securities $ 497 $ (5 ) $ 584 $ (6 ) $ 1,081 $ (11 ) U.S. Government Bonds 6,174 (54 ) 14,844 (461 ) 21,018 (515 ) Municipal Obligations 2,020 (23 ) 9,018 (540 ) 11,038 (563 ) Corporate Obligations 1,498 (30 ) 3,300 (166 ) 4,798 (196 ) Total Debt Securities 10,189 (112 ) 27,746 (1,173 ) 37,935 (1,285 ) Common Stock 2,146 (504 ) — — 2,146 (504 ) Institutional Equity Funds-International Equity 21,360 (1,774 ) — — 21,360 (1,774 ) Total Temporarily Impaired Securities $ 33,695 $ (2,390 ) $ 27,746 $ (1,173 ) $ 61,441 $ (3,563 ) _________________ (1) Includes 93 securities. December 31, 2015 Less than 12 Months 12 Months or Longer Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Description of Securities (2) : Federal Agency Mortgage Backed Securities $ 9,383 $ (97 ) $ 1,113 $ (47 ) $ 10,496 $ (144 ) U.S. Government Bonds 24,094 (310 ) 14,272 (623 ) 38,366 (933 ) Municipal Obligations 8,286 (160 ) 7,388 (446 ) 15,674 (606 ) Corporate Obligations 6,058 (722 ) 2,307 (228 ) 8,365 (950 ) Total Debt Securities 47,821 (1,289 ) 25,080 (1,344 ) 72,901 (2,633 ) Common Stock 3,584 (344 ) — — 3,584 (344 ) Institutional Equity Funds-International Equity 22,454 (768 ) — — 22,454 (768 ) Total Temporarily Impaired Securities $ 73,859 $ (2,401 ) $ 25,080 $ (1,344 ) $ 98,939 $ (3,745 ) _________________ (2) Includes 133 securities. The Company monitors the length of time specific securities trade 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. The Company recognizes impairment losses on certain of its securities deemed to be other than temporary. In accordance with the FASB guidance, these impairment losses are recognized in net income, and a lower cost basis is established for these securities. In addition, the Company will research the future prospects of individual securities as necessary. The Company does not anticipate expending monies held in trust before 2044 or a later period when decommissioning of Palo Verde begins. For the three, six, and twelve months ended June 30, 2016 and 2015, the Company recognized other than temporary impairment losses on its available-for-sale securities as follow (in thousands): Three Months Ended Six Months Ended Twelve Months Ended June 30, June 30, June 30, 2016 2015 2016 2015 2016 2015 Unrealized holding losses included in pre-tax income $ — $ — $ (156 ) $ — $ (494 ) $ — The reported securities 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): June 30, 2016 December 31, 2015 Fair Value Unrealized Gains Fair Value Unrealized Gains Description of Securities: Federal Agency Mortgage Backed Securities $ 17,852 $ 725 $ 9,589 $ 438 U.S. Government Bonds 37,332 1,670 12,033 136 Municipal Obligations 11,747 539 8,671 332 Corporate Obligations 17,455 1,265 10,110 368 Total Debt Securities 84,386 4,199 40,403 1,274 Common Stock 67,574 34,603 72,636 37,001 Equity Mutual Funds 29,153 863 18,853 91 Cash and Cash Equivalents 5,686 — 8,204 — Total $ 186,799 $ 39,665 $ 140,096 $ 38,366 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 of these available-for-sale securities as of June 30, 2016 is as follows (in thousands): Total 2016 2017 2021 through 2025 2026 and Beyond Municipal Debt Obligations $ 22,785 $ 711 $ 8,957 $ 11,727 $ 1,390 Corporate Debt Obligations 22,253 — 4,799 8,920 8,534 U.S. Government Bonds 58,350 3,404 27,172 14,676 13,098 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 three, six, and twelve months ended June 30, 2016 and 2015 and the related effects on pre-tax income are as follows (in thousands): Three Months Ended Six Months Ended Twelve Months Ended June 30, June 30, June 30, 2016 2015 2016 2015 2016 2015 Proceeds from sales or maturities of available-for-sale securities $ 16,634 $ 12,516 $ 40,712 $ 37,158 $ 106,121 $ 109,095 Gross realized gains included in pre-tax income $ 2,409 $ 33 $ 4,241 $ 3,815 $ 12,805 $ 8,410 Gross realized losses included in pre-tax income (299 ) (215 ) (587 ) (252 ) (1,262 ) (464 ) Gross unrealized losses included in pre-tax income — — (156 ) — (494 ) — Net gains (losses) included in pre-tax income $ 2,110 $ (182 ) $ 3,498 $ 3,563 $ 11,049 $ 7,946 Net unrealized holding gains (losses) included in accumulated other comprehensive income $ 2,790 $ (1,563 ) $ 4,980 $ (549 ) $ 2,623 $ 3,210 Net (gains) losses reclassified from accumulated other comprehensive income (2,110 ) 182 (3,498 ) (3,563 ) (11,049 ) (7,946 ) Net gains (losses) in other comprehensive income $ 680 $ (1,381 ) $ 1,482 $ (4,112 ) $ (8,426 ) $ (4,736 ) Fair Value Measurements. The 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 Institutional Funds 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 and primarily based on internal Company analysis using models and various other analysis. Financial assets utilizing Level 3 inputs are the Company's investment 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. The 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. The fair value of the Company's decommissioning trust funds and investments in debt securities at June 30, 2016 and December 31, 2015 , and the level within the three levels of the fair value hierarchy defined by the FASB guidance are presented in the table below (in thousands): Description of Securities Fair Value as of June 30, 2016 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Trading Securities: Investments in Debt Securities $ 1,376 $ — $ — $ 1,376 Available for sale: U.S. Government Bonds $ 58,350 $ 58,350 $ — $ — Federal Agency Mortgage Backed Securities 18,933 — 18,933 — Municipal Bonds 22,785 — 22,785 — Corporate Asset Backed Obligations 22,253 — 22,253 — Subtotal Debt Securities 122,321 58,350 63,971 — Common Stock 69,720 69,720 — — Equity Mutual Funds 29,153 29,153 — — Institutional Funds-International Equity (1) 21,360 Cash and Cash Equivalents 5,686 5,686 — — Total Available for Sale $ 248,240 $ 162,909 $ 63,971 $ — Description of Securities Fair Value as of December 31, 2015 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Trading Securities: Investments in Debt Securities $ 1,543 $ — $ — $ 1,543 Available for sale: U.S. Government Bonds $ 50,399 $ 50,399 $ — $ — Federal Agency Mortgage Backed Securities 20,085 — 20,085 — Municipal Bonds 24,345 — 24,345 — Corporate Asset Backed Obligations 18,475 — 18,475 — Subtotal Debt Securities 113,304 50,399 62,905 — Common Stock 76,220 76,220 — — Equity Mutual Funds 18,853 18,853 — — Institutional Funds-International Equity (1) 22,454 Cash and Cash Equivalents 8,204 8,204 — — Total Available for Sale $ 239,035 $ 153,676 $ 62,905 $ — (1) In accordance with ASU 2015-07 Subtopic 820-10, certain investments that are measured at fair value using the NAV per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the statement of financial position. 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 three, six and twelve month periods ended June 30, 2016 and 2015 . There were no purchases, sales, issuances, and settlements related to the assets in the Level 3 fair value measurement category during the three, six and twelve months ended June 30, 2016 and 2015 .

Principles Of Preparation (Poli

Principles Of Preparation (Policy)	6 Months Ended
	Jun. 30, 2016
Accounting Policies [Abstract]
Use of Estimates, Policy	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. The Company evaluates its estimates on an on-going basis, including those related to depreciation, unbilled revenue, income taxes, fuel costs, pension and other post-retirement obligations and asset retirement obligations ("ARO"). Actual results could differ from those estimates.
Revenue Recognition, Policy	Revenues . Revenues related to the sale of electricity are generally recorded when service is provided 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 recorded for estimated amounts of energy delivered in the period following the customer's billing cycle to the end of 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 $36.5 million at June 30, 2016 and $21.7 million at December 31, 2015 . The Company presents revenues net of sales taxes in its statements of operations.
New Accounting Standards, Policy	New Accounting Standards. In April 2015, the Financial Accounting Standards Board ("FASB") issued Accounting Standards Update ("ASU") 2015-03, Interest - Imputation of Interest (Topic 715) to simplify the presentation of debt issuance costs. ASU 2015-03 requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability, consistent with debt discounts. The recognition and measurement guidance for debt issuance costs are not affected by this ASU. ASU 2015-03 is effective for financial statements issued for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. In August 2015, the FASB issued ASU 2015-15, Interest - Imputation of Interest (Subtopic 835-30), to provide further clarification to ASU 2015-03 as it relates to the presentation and subsequent measurement of debt issuance costs associated with line of credit arrangements. The Company implemented ASU 2015-03 and ASU 2015-15 in the first quarter of 2016, retrospectively to all prior periods presented in the Company's financial statements. The implementation of ASU 2015-03 did not have a material impact on the Company's results of operations. See Note J. In May 2015, the FASB issued ASU 2015-07, Fair Value Measurement (Topic 820) to eliminate the requirement to categorize investments in the fair value hierarchy if the fair value is measured at net asset value ("NAV") per share (or its equivalent) using the practical expedient in the FASB’s fair value measurement gui dance . Reporting entities must still provide sufficient information to enable users to reconcile total investments in the fair value hierarchy and total investments measured at fair value in the financial statements. Additionally, the scope of current disclosure requirements for investments eligible to be measured at NAV will be limited to investments to which the practical expedient is applied. This ASU is effective in fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. The ASU requires retrospective application. The Company implemented ASU 2015-07 in the first quarter of 2016, retrospectively to all prior periods presented in the Company's fair value disclosures. This guidance required a revision of the fair value disclosures but did not impact the Company's financial statements. The implementation of ASU 2015-07 did not have a material impact on the Company's results of operations. See Note J. In November 2015, the FASB issued ASU 2015-17, Balance Sheet Classification of Deferred Taxes to simplify the presentation of deferred income taxes. ASU 2015-17 requires that deferred tax liabilities and assets be classified as noncurrent in a classified statement of financial position. ASU 2015-17 can be applied prospectively or retrospectively and is effective for financial statements issued for annual periods beginning after December 15, 2016 and interim periods within those annual periods and early adoption is permitted . The Company elected to early adopt ASU 2015-17 retrospectively in the first quarter of 2016. The implementation of ASU 2015-17 did not have a material impact on the Company's results of operations. See Note F. In May 2014, the FASB issued 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 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 was originally intended to be effective for annual periods and interim periods within that reporting period beginning after December 15, 2016, for public business entities. In August 2015, FASB issued ASU 2015-14 to defer the effective date of ASU 2014-09 for all entities by one year. Public business entities will apply the guidance in ASU 2014-09 to annual reporting periods beginning after December 15, 2017 and interim periods within that reporting period. In March 2016, the FASB issued ASU 2016-08 to clarify the implementation guidance on principal versus agent consideration. In April 2016, the FASB issued ASU 2016-10 to clarify the implementation guidance on identifying performance obligations and licensing. In May 2016, the FASB issued ASU 2016-11, which rescinds certain SEC Staff Observer comments that are codified in FASB ASC Topic 605 (Revenue Recognition), effective upon adoption of Topic 606. In May 2016, the FASB issued ASU 2016-12, which makes narrow-scope amendments to ASU 2014-09, and provides practical expedients to simplify the transition to the new standard and to clarify certain aspects of the standard. Early adoption of ASU 2014-09 is permitted after December 15, 2016. The Company has not selected a transition method and is currently assessing the future impact of this ASU. In January 2016, the FASB issued ASU 2016-01, Financial Instruments-Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Liabilities to enhance the reporting model for financial instruments by addressing certain aspects of recognition, measurement, presentation, and disclosure. ASU 2016-01 generally requires entities to measure equity investments that do not result in consolidation and are not accounted for under the equity method at fair value and recognize any changes in fair value in net income. The guidance for classifying and measuring investments in debt securities and loans is not changed by this ASU, but requires entities to record changes in other comprehensive income. Financial assets and financial liabilities must be separately presented by measurement category on the balance sheet or in the accompanying notes to the financial statements. ASU 2016-01 clarifies the need for a valuation allowance on a deferred tax asset related to available-for-sale securities in combination with the entity's other deferred tax assets. The standard includes a requirement that businesses must report changes in the fair value of their own liabilities in other comprehensive income instead of earnings, and this is the only provision of the update for which the FASB is permitting early adoption. The remaining provisions of this ASU become effective for public companies for fiscal years beginning after December 15, 2017, including interim periods within those fiscal years. The Company is currently assessing the future impact of this ASU. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) to increase transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and requiring qualitative and quantitative disclosures on leasing agreements. ASU 2016-02 maintains a distinction between finance leases and operating leases similar to the distinction under previous leases guidance for capital leases and operating leases. The impact of leases reported in the Company's operating results and statement of cash flows are expected to be similar to previous GAAP. ASU 2016-02 requires the recognition in the statement of financial position, by the lessee, of a liability to make lease payments (the lease liability) and a right-of-use asset representing its right to use the underlying asset for the lease term. How leases are recorded in regard to financial position represents a significant change from previous GAAP. The lessee is permitted to make an accounting policy election to not recognize lease assets and lease liabilities for short-term leases. Implementation of the standard for public companies will be required for annual reporting periods beginning after December 15, 2018 and interim periods within that reporting period. Early adoption of ASU 2016-02 is permitted for all entities. Adoption of the new lease accounting standard will require the Company to apply the new standard to the earliest period using a modified retrospective approach. The Company is currently assessing the future impact of this ASU. In March 2016, the FASB issued ASU 2016-09, Compensation – Stock Compensation (Topic 718) Improvements to Employee Share-Based Payment Accounting to simplify the accounting for share-based payment transactions, including the income tax consequences, classification of awards either as equity or liabilities, and classification on the statements of cash flows. This ASU is effective for annual periods beginning after December 15, 2016, and interim periods within those annual periods. Early adoption is permitted. The Company is currently assessing the future impact of this ASU. In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326). ASU 2016-13 significantly changes how companies measure and recognize credit impairment for many financial assets. The new current expected credit loss model will require companies to immediately recognize an estimate of credit losses expected to occur over the remaining life of the financial assets that are in the scope of the standard. The ASU also makes targeted amendments to the current impairment model for available-for-sale debt securities. For public business entities, the provisions of ASU 2016-13 are effective for fiscal years and interim periods within that reporting period beginning after December 15, 2019. Early implementation is permitted as of the fiscal years beginning after December 15, 2018, including interim periods within those fiscal years. ASU 2016-13 will be applied in a modified-retrospective approach through a cumulative-effect adjustment to retained earnings as of the beginning of the first reporting period in which the guidance is implemented. The Company is currently assessing the future impact of this ASU.
Reclassification, Policy	Reclassification. Certain amounts in the financial statements for 2015 have been reclassified to conform to the 2016 presentation. The Company implemented ASU 2015-03 and ASU 2015-17 in the first quarter of 2016, retrospectively to all periods presented in the Company's financial statements. See Note J and Note F, respectively.

Principles Of Preparation (Tabl

Principles Of Preparation (Tables)	6 Months Ended
	Jun. 30, 2016
Supplemental Cash Flow Information [Abstract]
Cash Flow, Supplemental Disclosures	Supplemental Cash Flow Disclosures (in thousands) Six Months Ended June 30, 2016 2015 Cash paid (received) for: Interest on long-term debt and borrowings under the revolving credit facility $ 35,252 $ 30,922 Income tax paid, net 2,703 1,680 Non-cash investing and financing activities: Changes in accrued plant additions (6,966 ) (1,227 ) Grants of restricted shares of common stock 1,236 1,106

Accumulated Other Comprehensi20

Accumulated Other Comprehensive Income (Tables)	6 Months Ended
	Jun. 30, 2016
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): Three Months Ended June 30, 2016 Three Months Ended June 30, 2015 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) 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 beginning of period $ (30,256 ) $ 28,394 $ (11,770 ) $ (13,632 ) $ (34,628 ) $ 36,782 $ (12,032 ) $ (9,878 ) Other comprehensive income (loss) before reclassifications — 2,224 — 2,224 — (1,191 ) — (1,191 ) Amounts reclassified from accumulated other comprehensive income (loss) (276 ) (1,693 ) 77 (1,892 ) 297 135 73 505 Balance at end of period $ (30,532 ) $ 28,925 $ (11,693 ) $ (13,300 ) $ (34,331 ) $ 35,726 $ (11,959 ) $ (10,564 ) Six Months Ended June 30, 2016 Six Months Ended June 30, 2015 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) 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 beginning of period $ (29,869 ) $ 27,765 $ (11,810 ) $ (13,914 ) $ (34,884 ) $ 38,957 $ (12,074 ) $ (8,001 ) Other comprehensive income (loss) before reclassifications — 3,966 — 3,966 — (369 ) — (369 ) Amounts reclassified from accumulated other comprehensive income (loss) (663 ) (2,806 ) 117 (3,352 ) 553 (2,862 ) 115 (2,194 ) Balance at end of period $ (30,532 ) $ 28,925 $ (11,693 ) $ (13,300 ) $ (34,331 ) $ 35,726 $ (11,959 ) $ (10,564 ) Twelve Months Ended June 30, 2016 Twelve Months Ended June 30, 2015 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) 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 beginning of period $ (34,331 ) $ 35,726 $ (11,959 ) $ (10,564 ) $ (9,539 ) $ 39,483 $ (12,214 ) $ 17,730 Other comprehensive income (loss) before reclassifications 3,777 2,080 — 5,857 (24,775 ) 2,681 — (22,094 ) Amounts reclassified from accumulated other comprehensive income (loss) 22 (8,881 ) 266 (8,593 ) (17 ) (6,438 ) 255 (6,200 ) Balance at end of period $ (30,532 ) $ 28,925 $ (11,693 ) $ (13,300 ) $ (34,331 ) $ 35,726 $ (11,959 ) $ (10,564 )
Reclassification out of Accumulated Other Comprehensive Income	Amounts reclassified from accumulated other comprehensive income (loss) for the three, six and twelve months ended June 30, 2016 and 2015 are as follows (in thousands): Details about Accumulated Other Comprehensive Income (Loss) Components Three Months Ended June 30, Six Months Ended June 30, Twelve Months Ended June 30, Affected Line Item in the Statement of Operations 2016 2015 2016 2015 2016 2015 Amortization of pension and post-retirement benefit costs: Prior service benefit $ 1,664 $ 1,662 $ 3,330 $ 3,325 $ 6,579 $ 7,455 (a) Net loss (1,222 ) (2,250 ) (2,445 ) (4,500 ) (6,567 ) (7,730 ) (a) 442 (588 ) 885 (1,175 ) 12 (275 ) (a) Income tax effect (166 ) 291 (222 ) 622 (34 ) 292 Income tax expense 276 (297 ) 663 (553 ) (22 ) 17 (a) Marketable securities: Net realized gain (loss) on sale of securities 2,110 (182 ) 3,498 3,563 11,049 7,946 Investment and interest income, net 2,110 (182 ) 3,498 3,563 11,049 7,946 Income before income taxes Income tax effect (417 ) 47 (692 ) (701 ) (2,168 ) (1,508 ) Income tax expense 1,693 (135 ) 2,806 2,862 8,881 6,438 Net income Loss on cash flow hedge: Amortization of loss (123 ) (116 ) (245 ) (230 ) (482 ) (452 ) Interest on long-term debt and revolving credit facility (123 ) (116 ) (245 ) (230 ) (482 ) (452 ) Income before income taxes Income tax effect 46 43 128 115 216 197 Income tax expense (77 ) (73 ) (117 ) (115 ) (266 ) (255 ) Net income Total reclassifications $ 1,892 $ (505 ) $ 3,352 $ 2,194 $ 8,593 $ 6,200 (a) These items are included in the computation of net periodic benefit cost. See Note I, Employee Benefits, for additional information.

Common Stock (Tables)

Common Stock (Tables)	6 Months Ended
	Jun. 30, 2016
Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]
Schedule of Earnings Per Share, Basic and Diluted	Basic and Diluted Earnings Per Share . The basic and diluted earnings per share are presented below (in thousands except for share data): Three Months Ended June 30, 2016 2015 Weighted average number of common shares outstanding: Basic number of common shares outstanding 40,345,150 40,269,885 Dilutive effect of unvested performance awards 54,341 32,809 Diluted number of common shares outstanding 40,399,491 40,302,694 Basic net income per common share: Net income $ 22,284 $ 21,072 Income allocated to participating restricted stock (65 ) (65 ) Net income available to common shareholders $ 22,219 $ 21,007 Diluted net income per common share: Net income $ 22,284 $ 21,072 Income reallocated to participating restricted stock (65 ) (65 ) Net income available to common shareholders $ 22,219 $ 21,007 Basic net income per common share: Distributed earnings $ 0.310 $ 0.295 Undistributed earnings 0.240 0.225 Basic net income per common share $ 0.550 $ 0.520 Diluted net income per common share: Distributed earnings $ 0.310 $ 0.295 Undistributed earnings 0.240 0.225 Diluted net income per common share $ 0.550 $ 0.520 Six Months Ended June 30, 2016 2015 Weighted average number of common shares outstanding: Basic number of common shares outstanding 40,335,236 40,256,615 Dilutive effect of unvested performance awards 45,404 28,142 Diluted number of common shares outstanding 40,380,640 40,284,757 Basic net income per common share: Net income $ 16,476 $ 24,530 Income allocated to participating restricted stock (66 ) (71 ) Net income available to common shareholders $ 16,410 $ 24,459 Diluted net income per common share: Net income $ 16,476 $ 24,530 Income reallocated to participating restricted stock (66 ) (71 ) Net income available to common shareholders $ 16,410 $ 24,459 Basic net income per common share: Distributed earnings $ 0.605 $ 0.575 Undistributed earnings (0.195 ) 0.035 Basic net income per common share $ 0.410 $ 0.610 Diluted net income per common share: Distributed earnings $ 0.605 $ 0.575 Undistributed earnings (0.195 ) 0.035 Diluted net income per common share $ 0.410 $ 0.610 Twelve Months Ended June 30, 2016 2015 Weighted average number of common shares outstanding: Basic number of common shares outstanding 40,314,032 40,236,466 Dilutive effect of unvested performance awards 42,207 26,838 Diluted number of common shares outstanding 40,356,239 40,263,304 Basic net income per common share: Net income $ 73,864 $ 81,247 Income allocated to participating restricted stock (210 ) (253 ) Net income available to common shareholders $ 73,654 $ 80,994 Diluted net income per common share: Net income $ 73,864 $ 81,247 Income reallocated to participating restricted stock (210 ) (253 ) Net income available to common shareholders $ 73,654 $ 80,994 Basic net income per common share: Distributed earnings $ 1.195 $ 1.135 Undistributed earnings 0.635 0.875 Basic net income per common share $ 1.830 $ 2.010 Diluted net income per common share: Distributed earnings $ 1.195 $ 1.135 Undistributed earnings 0.635 0.875 Diluted net income per common share $ 1.830 $ 2.010
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: Three Months Ended Six months ended Twelve Months Ended June 30, June 30, June 30, 2016 2015 2016 2015 2016 2015 Restricted stock awards 42,759 48,669 51,111 58,432 52,714 59,380 Performance shares (a) 62,995 59,898 62,995 59,898 56,089 48,136 (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.

Employee Benefits (Tables)

Employee Benefits (Tables)	6 Months Ended
	Jun. 30, 2016
Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Schedule of Net Benefit Costs	The net periodic benefit cost recognized for the three, six and twelve months ended June 30, 2016 and 2015 is made up of the components listed below as determined using the projected unit credit actuarial cost method (in thousands): Three Months Ended Six Months Ended Twelve Months Ended June 30, June 30, June 30, 2016 2015 2016 2015 2016 2015 Components of net periodic benefit cost: Service cost $ 1,905 $ 2,100 $ 3,810 $ 4,200 $ 8,402 $ 8,425 Interest cost 3,265 3,625 6,530 7,250 13,775 14,632 Expected return on plan assets (4,713 ) (4,948 ) (9,425 ) (9,895 ) (19,325 ) (19,258 ) Amortization of: Net loss 1,887 2,750 3,775 5,500 8,922 10,065 Prior service benefit (877 ) (887 ) (1,755 ) (1,775 ) (3,486 ) (3,528 ) Net periodic benefit cost $ 1,467 $ 2,640 $ 2,935 $ 5,280 $ 8,288 $ 10,336
Other Postretirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Schedule of Net Benefit Costs	The net periodic benefit cost recognized for the three, six and twelve months ended June 30, 2016 and 2015 is made up of the components listed below (in thousands): Three Months Ended Six Months Ended Twelve Months Ended June 30, June 30, June 30, 2016 2015 2016 2015 2016 2015 Components of net periodic benefit cost: Service cost $ 715 $ 875 $ 1,430 $ 1,750 $ 3,134 $ 3,173 Interest cost 872 1,025 1,745 2,050 3,730 4,281 Expected return on plan assets (460 ) (525 ) (920 ) (1,050 ) (1,940 ) (2,108 ) Amortization of: Prior service benefit (787 ) (775 ) (1,575 ) (1,550 ) (3,093 ) (3,927 ) Net gain (665 ) (500 ) (1,330 ) (1,000 ) (2,355 ) (2,335 ) Net periodic benefit cost (benefit) $ (325 ) $ 100 $ (650 ) $ 200 $ (524 ) $ (916 )

Financial Instruments And Inv23

Financial Instruments And Investments (Tables)	6 Months Ended
	Jun. 30, 2016
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): June 30, 2016 December 31, 2015 Carrying Amount (1) Estimated Fair Value Carrying Amount (1) Estimated Fair Value Pollution Control Bonds $ 190,637 $ 214,132 $ 190,499 $ 212,624 Senior Notes 992,924 1,193,209 837,475 829,864 RGRT Senior Notes (2) 94,740 101,215 94,686 100,345 RCF (2) 101,614 101,614 141,738 141,738 Total $ 1,379,915 $ 1,610,170 $ 1,264,398 $ 1,284,571 _______________ (1) The Company implemented ASU 2015-03, Interest - Imputation of Interest, which requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability. ASU 2015-03 is effective for financial statements issued for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. The impact of ASU 2015-03 on the Company's Balance Sheet was to reclassify $11.6 million of other deferred charges to long-term debt, net of current portion at December 31, 2015. (2) Nuclear fuel financing, as of June 30, 2016 and December 31, 2015 , is funded through the $95 million RGRT Senior Notes and $34.6 million and $33.7 million , respectively under the RCF. As of June 30, 2016 , $67.0 million was outstanding under the RCF for working capital or general corporate purposes. As of December 31, 2015 , $108.0 million 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 quarter reflecting c urrent 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): June 30, 2016 Less than 12 Months 12 Months or Longer Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Description of Securities (1) : Federal Agency Mortgage Backed Securities $ 497 $ (5 ) $ 584 $ (6 ) $ 1,081 $ (11 ) U.S. Government Bonds 6,174 (54 ) 14,844 (461 ) 21,018 (515 ) Municipal Obligations 2,020 (23 ) 9,018 (540 ) 11,038 (563 ) Corporate Obligations 1,498 (30 ) 3,300 (166 ) 4,798 (196 ) Total Debt Securities 10,189 (112 ) 27,746 (1,173 ) 37,935 (1,285 ) Common Stock 2,146 (504 ) — — 2,146 (504 ) Institutional Equity Funds-International Equity 21,360 (1,774 ) — — 21,360 (1,774 ) Total Temporarily Impaired Securities $ 33,695 $ (2,390 ) $ 27,746 $ (1,173 ) $ 61,441 $ (3,563 ) _________________ (1) Includes 93 securities. December 31, 2015 Less than 12 Months 12 Months or Longer Total Fair Value Unrealized Losses Fair Value Unrealized Losses Fair Value Unrealized Losses Description of Securities (2) : Federal Agency Mortgage Backed Securities $ 9,383 $ (97 ) $ 1,113 $ (47 ) $ 10,496 $ (144 ) U.S. Government Bonds 24,094 (310 ) 14,272 (623 ) 38,366 (933 ) Municipal Obligations 8,286 (160 ) 7,388 (446 ) 15,674 (606 ) Corporate Obligations 6,058 (722 ) 2,307 (228 ) 8,365 (950 ) Total Debt Securities 47,821 (1,289 ) 25,080 (1,344 ) 72,901 (2,633 ) Common Stock 3,584 (344 ) — — 3,584 (344 ) Institutional Equity Funds-International Equity 22,454 (768 ) — — 22,454 (768 ) Total Temporarily Impaired Securities $ 73,859 $ (2,401 ) $ 25,080 $ (1,344 ) $ 98,939 $ (3,745 ) _________________ (2) Includes 133 securities.
Unrealized Holding Losses Included In Pre-Tax Income	For the three, six, and twelve months ended June 30, 2016 and 2015, the Company recognized other than temporary impairment losses on its available-for-sale securities as follow (in thousands): Three Months Ended Six Months Ended Twelve Months Ended June 30, June 30, June 30, 2016 2015 2016 2015 2016 2015 Unrealized holding losses included in pre-tax income $ — $ — $ (156 ) $ — $ (494 ) $ —
Available-For-Sale-Securities, Continuous Unrealized Gain Position	The table below presents the unrecognized gross unrealized gains and the fair value of these securities, aggregated by investment category (in thousands): June 30, 2016 December 31, 2015 Fair Value Unrealized Gains Fair Value Unrealized Gains Description of Securities: Federal Agency Mortgage Backed Securities $ 17,852 $ 725 $ 9,589 $ 438 U.S. Government Bonds 37,332 1,670 12,033 136 Municipal Obligations 11,747 539 8,671 332 Corporate Obligations 17,455 1,265 10,110 368 Total Debt Securities 84,386 4,199 40,403 1,274 Common Stock 67,574 34,603 72,636 37,001 Equity Mutual Funds 29,153 863 18,853 91 Cash and Cash Equivalents 5,686 — 8,204 — Total $ 186,799 $ 39,665 $ 140,096 $ 38,366
Contractual Year For Maturity Of Available-For-Sale Securities	The contractual year for maturity of these available-for-sale securities as of June 30, 2016 is as follows (in thousands): Total 2016 2017 2021 through 2025 2026 and Beyond Municipal Debt Obligations $ 22,785 $ 711 $ 8,957 $ 11,727 $ 1,390 Corporate Debt Obligations 22,253 — 4,799 8,920 8,534 U.S. Government Bonds 58,350 3,404 27,172 14,676 13,098
Sale of Securities And The Related Effects On Pre-Tax Income	The proceeds from the sale of these securities during the three, six, and twelve months ended June 30, 2016 and 2015 and the related effects on pre-tax income are as follows (in thousands): Three Months Ended Six Months Ended Twelve Months Ended June 30, June 30, June 30, 2016 2015 2016 2015 2016 2015 Proceeds from sales or maturities of available-for-sale securities $ 16,634 $ 12,516 $ 40,712 $ 37,158 $ 106,121 $ 109,095 Gross realized gains included in pre-tax income $ 2,409 $ 33 $ 4,241 $ 3,815 $ 12,805 $ 8,410 Gross realized losses included in pre-tax income (299 ) (215 ) (587 ) (252 ) (1,262 ) (464 ) Gross unrealized losses included in pre-tax income — — (156 ) — (494 ) — Net gains (losses) included in pre-tax income $ 2,110 $ (182 ) $ 3,498 $ 3,563 $ 11,049 $ 7,946 Net unrealized holding gains (losses) included in accumulated other comprehensive income $ 2,790 $ (1,563 ) $ 4,980 $ (549 ) $ 2,623 $ 3,210 Net (gains) losses reclassified from accumulated other comprehensive income (2,110 ) 182 (3,498 ) (3,563 ) (11,049 ) (7,946 ) Net gains (losses) in other comprehensive income $ 680 $ (1,381 ) $ 1,482 $ (4,112 ) $ (8,426 ) $ (4,736 )
Fair Value, Measurement Inputs, Disclosure	The fair value of the Company's decommissioning trust funds and investments in debt securities at June 30, 2016 and December 31, 2015 , and the level within the three levels of the fair value hierarchy defined by the FASB guidance are presented in the table below (in thousands): Description of Securities Fair Value as of June 30, 2016 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Trading Securities: Investments in Debt Securities $ 1,376 $ — $ — $ 1,376 Available for sale: U.S. Government Bonds $ 58,350 $ 58,350 $ — $ — Federal Agency Mortgage Backed Securities 18,933 — 18,933 — Municipal Bonds 22,785 — 22,785 — Corporate Asset Backed Obligations 22,253 — 22,253 — Subtotal Debt Securities 122,321 58,350 63,971 — Common Stock 69,720 69,720 — — Equity Mutual Funds 29,153 29,153 — — Institutional Funds-International Equity (1) 21,360 Cash and Cash Equivalents 5,686 5,686 — — Total Available for Sale $ 248,240 $ 162,909 $ 63,971 $ — Description of Securities Fair Value as of December 31, 2015 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Trading Securities: Investments in Debt Securities $ 1,543 $ — $ — $ 1,543 Available for sale: U.S. Government Bonds $ 50,399 $ 50,399 $ — $ — Federal Agency Mortgage Backed Securities 20,085 — 20,085 — Municipal Bonds 24,345 — 24,345 — Corporate Asset Backed Obligations 18,475 — 18,475 — Subtotal Debt Securities 113,304 50,399 62,905 — Common Stock 76,220 76,220 — — Equity Mutual Funds 18,853 18,853 — — Institutional Funds-International Equity (1) 22,454 Cash and Cash Equivalents 8,204 8,204 — — Total Available for Sale $ 239,035 $ 153,676 $ 62,905 $ — (1) In accordance with ASU 2015-07 Subtopic 820-10, certain investments that are measured at fair value using the NAV per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the statement of financial position.

Principles Of Preparation (Accr

Principles Of Preparation (Accrued Unbilled Revenues) (Details) - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Accounting Policies [Abstract]
Accrued unbilled revenues	$ 36.5	$ 21.7

Principles Of Preparation (Supp

Principles Of Preparation (Supplemental Cash Flow Disclosures) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Supplemental Cash Flow Information [Abstract]
Interest on long-term debt and borrowing under the revolving credit facility	$ 35,252	$ 30,922
Income tax paid, net	2,703	1,680
Changes in accrued plant additions	(6,966)	(1,227)
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants of restricted shares of common stock	$ 1,236	$ 1,106

Accumulated Other Comprehensi26

Accumulated Other Comprehensive Income by Component (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended		12 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), beginning balance				$ (13,914)
Accumulated Other Comprehensive Income (Loss), ending balance		$ (13,300)		(13,300)		$ (13,300)
Accumulated Defined Benefit Plans Adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), beginning balance		(30,256)	$ (34,628)	(29,869)	$ (34,884)	(34,331)	$ (9,539)
Other Comprehensive Income (Loss) before Reclassifications		0	0	0	0	3,777	(24,775)
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)	[1]	(276)	297	(663)	553	22	(17)
Accumulated Other Comprehensive Income (Loss), ending balance		(30,532)	(34,331)	(30,532)	(34,331)	(30,532)	(34,331)
Accumulated Net Unrealized Investment Gain (Loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), beginning balance		28,394	36,782	27,765	38,957	35,726	39,483
Other Comprehensive Income (Loss) before Reclassifications		2,224	(1,191)	3,966	(369)	2,080	2,681
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)		(1,693)	135	(2,806)	(2,862)	(8,881)	(6,438)
Accumulated Other Comprehensive Income (Loss), ending balance		28,925	35,726	28,925	35,726	28,925	35,726
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), beginning balance		(11,770)	(12,032)	(11,810)	(12,074)	(11,959)	(12,214)
Other Comprehensive Income (Loss) before Reclassifications		0	0	0	0	0	0
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)		77	73	117	115	266	255
Accumulated Other Comprehensive Income (Loss), ending balance		(11,693)	(11,959)	(11,693)	(11,959)	(11,693)	(11,959)
Accumulated Other Comprehensive Income (Loss), Net of Tax
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Accumulated Other Comprehensive Income (Loss), beginning balance		(13,632)	(9,878)	(13,914)	(8,001)	(10,564)	17,730
Other Comprehensive Income (Loss) before Reclassifications		2,224	(1,191)	3,966	(369)	5,857	(22,094)
Amounts Reclassified from Accumulated Other Comprehensive Income (Loss)		(1,892)	505	(3,352)	(2,194)	(8,593)	(6,200)
Accumulated Other Comprehensive Income (Loss), ending balance		$ (13,300)	$ (10,564)	$ (13,300)	$ (10,564)	$ (13,300)	$ (10,564)
[1]	These items are included in the computation of net periodic benefit cost. See Note I, Employee Benefits, for additional information.

Accumulated Other Comprehensi27

Accumulated Other Comprehensive Income Amounts Reclassified (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended		12 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Accumulated Other Comprehensive Income (Loss) [Line Items]
Income (Loss) before income tax		$ 33,734	$ 30,577	$ 24,765	$ 35,019	$ 106,559	$ 116,588
Income tax expense		(11,450)	(9,505)	(8,289)	(10,489)	(32,695)	(35,341)
Net (Income) Loss		22,284	21,072	16,476	24,530	73,864	81,247
Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	[1]	1,664	1,662	3,330	3,325	6,579	7,455
Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	[1]	(1,222)	(2,250)	(2,445)	(4,500)	(6,567)	(7,730)
Accumulated Defined Benefit Plans Adjustment
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	[1]	442	(588)	885	(1,175)	12	(275)
Reclassification from AOCI, Current Period, Tax		(166)	291	(222)	622	(34)	292
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	[1]	276	(297)	663	(553)	(22)	17
Accumulated Net Unrealized Investment Gain (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax		1,693	(135)	2,806	2,862	8,881	6,438
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax		(77)	(73)	(117)	(115)	(266)	(255)
Reclassification out of Accumulated Other Comprehensive Income
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax		1,892	(505)	3,352	2,194	8,593	6,200
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		2,110	(182)	3,498	3,563	11,049	7,946
Income (Loss) before income tax		2,110	(182)	3,498	3,563	11,049	7,946
Income tax expense		(417)	47	(692)	(701)	(2,168)	(1,508)
Net (Income) Loss		1,693	(135)	2,806	2,862	8,881	6,438
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]
Income (Loss) before income tax		(123)	(116)	(245)	(230)	(482)	(452)
Income tax expense		46	43	128	115	216	197
Net (Income) Loss		(77)	(73)	(117)	(115)	(266)	(255)
Interest Rate Contract | 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		$ (123)	$ (116)	$ (245)	$ (230)	$ (482)	$ (452)
[1]	These items are included in the computation of net periodic benefit cost. See Note I, Employee Benefits, for additional information.

Regulation (Narrative) (Details

Regulation (Narrative) (Details) $ in Thousands

Jul. 21, 2016USD ($)

Jul. 06, 2016USD ($)

Jun. 08, 2016USD ($)

Apr. 29, 2016USD ($)

Mar. 30, 2016USD ($)

Mar. 24, 2016USD ($)

Nov. 05, 2015USD ($)

Oct. 28, 2015USD ($)

Aug. 10, 2015USD ($)

May 20, 2015

May 11, 2015USD ($)

May 01, 2015USD ($)

Feb. 17, 2015

Dec. 01, 2014USD ($)

Nov. 14, 2014USD ($)

Jul. 11, 2014USD ($)

May 01, 2014USD ($)

Jun. 30, 2016USD ($)MW

Jun. 30, 2015USD ($)

Dec. 31, 2015USD ($)

Oct. 19, 2015USD ($)

Oct. 07, 2015USD ($)

Over-collection of fuel revenues

$ 2,063

$ 4,023

Jointly Owned Utility Plant, Proportionate Ownership Share

7.00%

Proceeds from issuance of senior notes

$ 157,052

$ 0

Interest Payable, Current

13,267

$ 12,649

PUCT Docket No. 41852

Reconcilable Fuel Expense

$ 545,300

Fuel Reconciliation Period

45 months

Fixed Fuel Factor | PUCT Docket No. 44633

Decrease In Fixed Fuel Factor, Percentage

24.00%

Four Corners Generating Station

Purchase and Sale Agreement, Execution Date

Feb. 17, 2015

Mine Reclamation Liability, Noncurrent

$ 19,500

Subsequent Event | Four Corners Generating Station

Closing Date of Sale

Jul. 6, 2016

Mine Reclamation Liability, Noncurrent

$ 19,500

PUCT

Period To Relate Back New Rates

155 days

Number Of Parties Opposing Regulatory Matter Settlement

4

Public Utilities Requested Performance Incentive Bonus Related To Energy Efficiency Program

$ 668

$ 1,000

$ 2,000

Public Utilities Approved Performance Incentive Bonus Related To Energy Efficiency Program

$ 1,000

$ 2,000

Over-collection of fuel revenues

$ 1,000

Fuel Reconciliation Period

36 months

Fuel Over And Under Materiality Threshold Percentage

4.00%

PUCT | Non-Fuel Base Rate

Public Utilities, Requested Rate Increase (Decrease), Amount

$ 71,500

Public Utilities, Requested Rate Increase, Amended, Amount

$ 63,300

Public Utilities, Interim Rate Increase, Amount

$ 37,000

PUCT | Four Corners Generating Station

Purchase and Sale Agreement, Execution Date

Feb. 17, 2015

PUCT | Montana Power Station

Number of power generation units authorized to be constructed

4

PUCT | Montana Power Station Units 1 and 2

Property, Plant and Equipment, Operational Date

Mar. 20, 2015

PUCT | Montana Power Station Unit 3

Property, Plant and Equipment, Operational Date

May 3, 2016

PUCT | Community Solar At Montana Power Station

Electric Capacity | MW

3

PUCT | Minimum

Fixed Fuel Factor Revision Period, in Months

4 months

PUCT | Maximum

Surcharge Or Refund Period

18 months

PUCT | Subsequent Event

Public Utilities, Annual Depreciation Expense Decrease

$ 8,500

Public Utilities, Interim Return On Equity, Percentage

9.70%

PUCT | Subsequent Event | Non-Fuel Base Rate

Public Utilities, Interim Rate Increase, Amount

$ 37,000

PUCT | Subsequent Event | Four Corners Generating Station

Closing Date of Sale

Jul. 6, 2016

PUCT | Subsequent Event | Four Corners Generating Station | Non-Fuel Base Rate

Public Utilities, Requested Rate Increase (Decrease), Amount

$ 3,700

NMPRC

Over-collection of fuel revenues

$ 1,100

Public Utilities, Approved Return on Equity, Percentage

9.48%

Debt Instrument, Face Amount

$ 310,000

NMPRC | Non-Fuel Base Rate

Public Utilities, Requested Rate Increase (Decrease), Amount

$ 8,600

Public Utilities, Requested Rate Increase, Amended, Amount

$ 6,400

Public Utilities, Requested Rate Increase (Decrease), Percentage

7.10%

Public Utilities, Approved Rate Increase, Amount

$ 1,100

NMPRC | Fuel In Base Rate

Public Utilities, Requested Rate Increase (Decrease), Amount

$ (15,400)

Public Utilities, Requested Rate Increase (Decrease), Percentage

(21.50%)

NMPRC | Four Corners Generating Station

Purchase and Sale Agreement, Execution Date

Feb. 17, 2015

NMPRC | Montana Power Station

Number of power generation units authorized to be constructed

4

NMPRC | Montana Power Station Units 1 and 2

Property, Plant and Equipment, Operational Date

Mar. 20, 2015

NMPRC | Montana Power Station Unit 3

Property, Plant and Equipment, Operational Date

May 3, 2016

NMPRC | Holloman

Electric Capacity | MW

5

NMPRC | Four Corners Generating Station

Jointly Owned Utility Plant, Proportionate Ownership Share

7.00%

FERC

Debt Instrument, Face Amount

$ 310,000

Line of Credit Facility, Maximum Borrowing Capacity

400,000

Debt Issuance Authorization Date Range Start

Nov. 15, 2015

Debt Issuance Authorization Date Range End

Nov. 15, 2017

FERC | Four Corners Generating Station

Jointly Owned Utility Plant Entire Ownership Of Proportionate Interest, Percentage

100.00%

FERC | Subsequent Event | Four Corners Generating Station

Closing Date of Sale

Jul. 6, 2016

RGRT | NMPRC

Debt Instrument, Face Amount

$ 65,000

RGRT | FERC

Debt Instrument, Face Amount

$ 65,000

Scenario, Forecast | PUCT | Four Corners Generating Station

Mine Reclamation Liability, Noncurrent

$ 7,700

5.00% Senior Notes, Plus Premium, Due 2044 | NMPRC

Debt Instrument, Face Amount

$ 150,000

Debt Instrument, Issuance Date

Mar. 24, 2016

Debt Instrument, Interest Rate, Stated Percentage

5.00%

Debt Instrument, Maturity Date

Dec. 1, 2044

Proceeds from issuance of senior notes

$ 158,100

Interest Payable, Current

2,400

Debt Instrument, Unamortized Premium

7,100

5.00% Senior Notes, Plus Premium, Due 2044 | FERC

Debt Instrument, Face Amount

$ 150,000

Debt Instrument, Issuance Date

Mar. 24, 2016

Debt Instrument, Interest Rate, Stated Percentage

5.00%

Debt Instrument, Maturity Date

Dec. 1, 2044

Proceeds from issuance of senior notes

$ 158,100

Interest Payable, Current

2,400

Debt Instrument, Unamortized Premium

$ 7,100

5.00% Senior Notes, Net of Discount, Due 2044 | NMPRC

Debt Instrument, Face Amount

$ 150,000

Debt Instrument, Issuance Date

Dec. 1, 2014

Debt Instrument, Interest Rate, Stated Percentage

5.00%

Debt Instrument, Maturity Date

Dec. 1, 2044

5.00% Senior Notes, Net of Discount, Due 2044 | FERC

Debt Instrument, Face Amount

$ 150,000

Debt Instrument, Issuance Date

Dec. 1, 2014

Debt Instrument, Interest Rate, Stated Percentage

5.00%

Debt Instrument, Maturity Date

Dec. 1, 2044

5.00% Senior Notes, Combined, Due 2044 | NMPRC

Debt Instrument, Face Amount

$ 300,000

5.00% Senior Notes, Combined, Due 2044 | FERC

Debt Instrument, Face Amount

300,000

Revenue Subject to Refund | PUCT

Public Utilities, Revenue Subject to Refund Liability

$ 10,800

Palo Verde and Four Corners (N

Palo Verde and Four Corners (Narrative) (Details) - USD ($) $ in Thousands

Jul. 06, 2016

Mar. 31, 2016

Nov. 02, 2015

Jun. 01, 2015

Feb. 17, 2015

Oct. 31, 2014

Oct. 08, 2014

Aug. 18, 2014

Dec. 19, 2012

Jun. 30, 2016

Jun. 30, 2015

Dec. 31, 2015

Jointly Owned Utility Plant Interests [Line Items]

Proceeds from Sale of Property, Plant, and Equipment

$ 596

$ 0

Property, Plant and Equipment, Net

2,414,261

$ 2,286,458

Four Corners Generating Station

Jointly Owned Utility Plant Interests [Line Items]

Mine Reclamation Liability, Noncurrent

19,500

Asset Retirement Obligation

7,000

Purchase and Sale Agreement, Execution Date

Feb. 17, 2015

Property, Plant and Equipment, Net

$ 31,900

Suit Against Department of Energy for Spent Fuel

Jointly Owned Utility Plant Interests [Line Items]

Settlement Agreement, Counterparty's Name

U.S. Department of Energy

Lawsuit Filing Date

November 2, 2015

October 31, 2014

December 19, 2012

Settlement Agreement, Date

August 18, 2014

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

Jointly Owned Utility Plant Interests [Line Items]

Settlement, Amount

$ 1,900

$ 6,600

$ 9,100

Settlement Agreement Award Received, Date

Mar. 31, 2016

Jun. 1, 2015

Oct. 8, 2014

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

Jointly Owned Utility Plant Interests [Line Items]

Settlement, Amount

$ 12,000

$ 42,000

$ 57,400

Minimum | Suit Against Department of Energy for Spent Fuel

Jointly Owned Utility Plant Interests [Line Items]

Litigation, Period Covered

July 1, 2014

July 1, 2011

January 1, 2007

Maximum | Suit Against Department of Energy for Spent Fuel

Jointly Owned Utility Plant Interests [Line Items]

Litigation, Period Covered

June 30, 2015

June 30, 2014

June 30, 2011

Subsequent Event | Four Corners Generating Station

Jointly Owned Utility Plant Interests [Line Items]

Mine Reclamation Liability, Noncurrent

$ 19,500

Disposal Date

Jul. 6, 2016

Property, Plant and Equipment, Disposals

$ 32,000

Asset Retirement Obligation

7,000

Proceeds from Sale of Property, Plant, and Equipment

4,200

Public Utilities, Property, Plant and Equipment, Sales Price Adjustments

$ 1,300

Common Stock (Narrative) (Detai

Common Stock (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	Sep. 30, 2016	Sep. 14, 2016	Jul. 21, 2016	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Dividends, Common Stock, Cash				$ 12,500	$ 11,900	$ 24,474	$ 23,220	$ 48,400	$ 45,800
Common Stock, Dividends, Per Share, Declared				$ 0.310	$ 0.295	$ 0.605	$ 0.575	$ 1.195	$ 1.135
Scenario, Forecast
Dividends Payable, Date to be Paid	Sep. 30, 2016
Dividends Payable, Date of Record		Sep. 14, 2016
Subsequent Event
Dividends Payable, Date Declared			Jul. 21, 2016
Common Stock, Dividends, Per Share, Declared			$ 0.310

Common Stock (Basic And Diluted

Common Stock (Basic And Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Earnings Per Share [Abstract]
Basic number of common shares outstanding	40,345,150	40,269,885	40,335,236	40,256,615	40,314,032	40,236,466
Dilutive effect of unvested performance awards	54,341	32,809	45,404	28,142	42,207	26,838
Diluted number of common shares outstanding	40,399,491	40,302,694	40,380,640	40,284,757	40,356,239	40,263,304
Net income	$ 22,284	$ 21,072	$ 16,476	$ 24,530	$ 73,864	$ 81,247
Income allocated to participating restricted stock	(65)	(65)	(66)	(71)	(210)	(253)
Net income available to common shareholders, basic	22,219	21,007	16,410	24,459	73,654	80,994
Income reallocated to participating restricted stock	(65)	(65)	(66)	(71)	(210)	(253)
Net income available to common shareholders, diluted	$ 22,219	$ 21,007	$ 16,410	$ 24,459	$ 73,654	$ 80,994
Earnings Per Share, Basic, Distributed	$ 0.310	$ 0.295	$ 0.605	$ 0.575	$ 1.195	$ 1.135
Earnings Per Share, Basic, Undistributed	0.240	0.225	(0.195)	0.035	0.635	0.875
Basic net income per common share	0.550	0.520	0.410	0.610	1.830	2.010
Earnings Per Share, Diluted, Distributed	0.310	0.295	0.605	0.575	1.195	1.135
Earnings Per Share, Diluted, Undistributed	0.240	0.225	(0.195)	0.035	0.635	0.875
Diluted net income per common share	$ 0.550	$ 0.520	$ 0.410	$ 0.610	$ 1.830	$ 2.010

Common Stock (Antidilutive Secu

Common Stock (Antidilutive Securities Excluded From Computation Of Earnings Per Share) (Details) - shares		3 Months Ended		6 Months Ended		12 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Performance shares payout based upon performance		0	0	0	0	0	0
Performance shares payout level		100.00%	100.00%	100.00%	100.00%	100.00%	100.00%
Restricted Stock
Antidilutive Securities Excluded from the Computation of Diluted Earnings Per Share, Amount		42,759	48,669	51,111	58,432	52,714	59,380
Performance Shares
Antidilutive Securities Excluded from the Computation of Diluted Earnings Per Share, Amount	[1]	62,995	59,898	62,995	59,898	56,089	48,136
[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.

Income Taxes (Income Tax Rates)

Income Taxes (Income Tax Rates) (Details)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Income Tax [Line Items]
Consolidated effective tax rate	33.90%	31.10%	33.50%	30.00%	30.70%	30.30%
Federal statutory tax rate	35.00%	35.00%	35.00%	35.00%	35.00%	35.00%
Income Tax Rate Capital Gains	20.00%	20.00%	20.00%	20.00%	20.00%	20.00%

Income Taxes (Details)

Income Taxes (Details) - USD ($)	Jun. 30, 2016	Jun. 30, 2016
Accounting Standards Update 2015-17
Income Tax [Line Items]
Amounts previously reported, reclassified		$ 21.6
Internal Revenue Service (IRS) | Maximum
Income Tax [Line Items]
Tax Year Closed		2,011
NEW MEXICO | Maximum
Income Tax [Line Items]
Tax Year Closed		2,011
TEXAS | Earliest Tax Year
Income Tax [Line Items]
Income Tax Examination, Year under Examination		2,007
TEXAS | Latest Tax Year
Income Tax [Line Items]
Income Tax Examination, Year under Examination		2,011
ARIZONA | Earliest Tax Year
Income Tax [Line Items]
Tax Year Closed	2,009
ARIZONA | Latest Tax Year
Income Tax [Line Items]
Tax Year Closed	2,012

Commitments, Contingencies An35

Commitments, Contingencies And Uncertainties (Narrative) (Details)	Jul. 06, 2016	Apr. 22, 2016Countries	Jun. 30, 2016Decimals	Jul. 28, 2015States
Loss Contingencies [Line Items]
Number of States Affected by EPA's Emissions Budgets | States				13
Number of criteria emissions established under the Clear Air Act			6
Frequency of Review by Environmental Protection Agency			5 years
Jointly Owned Utility Plant, Proportionate Ownership Share			7.00%
Number of countries that signed the Paris Agreement | Countries		175
Frequency of Review by Countries Participating in the Paris Agreement		5 years
Minimum
Loss Contingencies [Line Items]
Public Utilities, Government Standard Emission Limit			70
Maximum
Loss Contingencies [Line Items]
Public Utilities, Government Standard Emission Limit			75
Subsequent Event | Four Corners Generating Station
Loss Contingencies [Line Items]
Date participation is ceased	Jul. 6, 2016

Employee Benefits (Retirement P

Employee Benefits (Retirement Plans And Other Postretirement Benefits) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1,905	$ 2,100	$ 3,810	$ 4,200	$ 8,402	$ 8,425
Interest cost	3,265	3,625	6,530	7,250	13,775	14,632
Expected return on plan assets	(4,713)	(4,948)	(9,425)	(9,895)	(19,325)	(19,258)
Amortization of prior service benefit	(877)	(887)	(1,755)	(1,775)	(3,486)	(3,528)
Amortization of net (gain) loss	1,887	2,750	3,775	5,500	8,922	10,065
Net periodic benefit cost (benefit)	1,467	2,640	2,935	5,280	8,288	10,336
Other Postretirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Service cost	715	875	1,430	1,750	3,134	3,173
Interest cost	872	1,025	1,745	2,050	3,730	4,281
Expected return on plan assets	(460)	(525)	(920)	(1,050)	(1,940)	(2,108)
Amortization of prior service benefit	(787)	(775)	(1,575)	(1,550)	(3,093)	(3,927)
Amortization of net (gain) loss	(665)	(500)	(1,330)	(1,000)	(2,355)	(2,335)
Net periodic benefit cost (benefit)	$ (325)	$ 100	$ (650)	$ 200	$ (524)	$ (916)

Employee Benefits (Narrative) (

Employee Benefits (Narrative) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2016USD ($)
Retirement Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Employer Contribution	$ 2.8
Defined Benefit Plan, Expected Contributions in Current Fiscal Year	6.2
Other Postretirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Employer Contribution	1.1
Defined Benefit Plan, Expected Contributions in Current Fiscal Year	$ 1.7

Financial Instruments And Inv38

Financial Instruments And Investments (Carrying Amount and Fair Value Amounts) (Details) - USD ($) $ in Thousands		Jun. 30, 2016	Dec. 31, 2015
Carrying (Reported) Amount, Fair Value Disclosure
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure	[1]	$ 1,379,915	$ 1,264,398
Carrying (Reported) Amount, Fair Value Disclosure | Pollution Control Bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure	[1]	190,637	190,499
Carrying (Reported) Amount, Fair Value Disclosure | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure	[1]	992,924	837,475
Carrying (Reported) Amount, Fair Value Disclosure | RGRT Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure	[1],[2]	94,740	94,686
Carrying (Reported) Amount, Fair Value Disclosure | Revolving Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure	[1],[2]	101,614	141,738
Estimate of Fair Value Measurement
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure		1,610,170	1,284,571
Estimate of Fair Value Measurement | Pollution Control Bonds
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure		214,132	212,624
Estimate of Fair Value Measurement | Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure		1,193,209	829,864
Estimate of Fair Value Measurement | RGRT Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure	[2]	101,215	100,345
Estimate of Fair Value Measurement | Revolving Credit Facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument, Fair Value Disclosure	[2]	$ 101,614	$ 141,738
[1]	The Company implemented ASU 2015-03, Interest - Imputation of Interest, which requires that debt issuance costs related to a recognized debt liability be presented in the balance sheet as a direct deduction from the carrying amount of that debt liability. ASU 2015-03 is effective for financial statements issued for fiscal years beginning after December 15, 2015, and interim periods within those fiscal years. The impact of ASU 2015-03 on the Company's Balance Sheet was to reclassify $11.6 million of other deferred charges to long-term debt, net of current portion at December 31, 2015.
[2]	Nuclear fuel financing, as of June 30, 2016 and December 31, 2015, is funded through the $95 million RGRT Senior Notes and $34.6 million and $33.7 million, respectively under the RCF. As of June 30, 2016, $67.0 million was outstanding under the RCF for working capital or general corporate purposes. As of December 31, 2015, $108.0 million 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 quarter reflecting current market rates. Consequently, the carrying value approximates fair value.

Financial Instruments And Inv39

Financial Instruments And Investments (Long-Term Debt and Short-Term Borrowings - Narratives) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Financial Instruments and Investments [Line Items]
Decommissioning Fund Investments	$ 248,240	$ 239,035
Accounting Standards Update 2015-03
Financial Instruments and Investments [Line Items]
Amounts previously reported, reclassified	11,600
Nuclear Fuel Financing
Financial Instruments and Investments [Line Items]
Line of Credit Facility, Amount Outstanding	34,600	33,700
Working Capital and General Purpose
Financial Instruments and Investments [Line Items]
Line of Credit Facility, Amount Outstanding	67,000	108,000
RGRT Senior Notes
Financial Instruments and Investments [Line Items]
Long-term Debt, Gross	$ 95,000	$ 95,000

Financial Instruments And Inv40

Financial Instruments And Investments (Marketable Securities Fair Value And Unrealized Losses) (Details) $ in Thousands	6 Months Ended		12 Months Ended
	Jun. 30, 2016USD ($)securities		Dec. 31, 2015USD ($)securities
Financial Instruments and Investments [Line Items]
Marketable Securities Fair Value Less than 12 Months	$ 33,695	[1]	$ 73,859	[2]
Marketable Securities Unrealized Losses Less Than 12 Months	(2,390)	[1]	(2,401)	[2]
Marketable Securities Fair Value 12 Months or Longer	27,746	[1]	25,080	[2]
Marketable Securities Unrealized Losses 12 Months or Longer	(1,173)	[1]	(1,344)	[2]
Marketable Securities Fair Value Total	61,441	[1]	98,939	[2]
Marketable Securities Unrealized Losses Total	$ (3,563)	[1]	$ (3,745)	[2]
Number of securities | securities	93		133
Debt Securities
Financial Instruments and Investments [Line Items]
Marketable Securities Fair Value Less than 12 Months	$ 10,189	[1]	$ 47,821	[2]
Marketable Securities Unrealized Losses Less Than 12 Months	(112)	[1]	(1,289)	[2]
Marketable Securities Fair Value 12 Months or Longer	27,746	[1]	25,080	[2]
Marketable Securities Unrealized Losses 12 Months or Longer	(1,173)	[1]	(1,344)	[2]
Marketable Securities Fair Value Total	37,935	[1]	72,901	[2]
Marketable Securities Unrealized Losses Total	(1,285)	[1]	(2,633)	[2]
Collateralized Mortgage Backed Securities
Financial Instruments and Investments [Line Items]
Marketable Securities Fair Value Less than 12 Months	497	[1]	9,383	[2]
Marketable Securities Unrealized Losses Less Than 12 Months	(5)	[1]	(97)	[2]
Marketable Securities Fair Value 12 Months or Longer	584	[1]	1,113	[2]
Marketable Securities Unrealized Losses 12 Months or Longer	(6)	[1]	(47)	[2]
Marketable Securities Fair Value Total	1,081	[1]	10,496	[2]
Marketable Securities Unrealized Losses Total	(11)	[1]	(144)	[2]
U.S. Government Bonds
Financial Instruments and Investments [Line Items]
Marketable Securities Fair Value Less than 12 Months	6,174	[1]	24,094	[2]
Marketable Securities Unrealized Losses Less Than 12 Months	(54)	[1]	(310)	[2]
Marketable Securities Fair Value 12 Months or Longer	14,844	[1]	14,272	[2]
Marketable Securities Unrealized Losses 12 Months or Longer	(461)	[1]	(623)	[2]
Marketable Securities Fair Value Total	21,018	[1]	38,366	[2]
Marketable Securities Unrealized Losses Total	(515)	[1]	(933)	[2]
Municipal Bonds
Financial Instruments and Investments [Line Items]
Marketable Securities Fair Value Less than 12 Months	2,020	[1]	8,286	[2]
Marketable Securities Unrealized Losses Less Than 12 Months	(23)	[1]	(160)	[2]
Marketable Securities Fair Value 12 Months or Longer	9,018	[1]	7,388	[2]
Marketable Securities Unrealized Losses 12 Months or Longer	(540)	[1]	(446)	[2]
Marketable Securities Fair Value Total	11,038	[1]	15,674	[2]
Marketable Securities Unrealized Losses Total	(563)	[1]	(606)	[2]
Corporate Debt Securities
Financial Instruments and Investments [Line Items]
Marketable Securities Fair Value Less than 12 Months	1,498	[1]	6,058	[2]
Marketable Securities Unrealized Losses Less Than 12 Months	(30)	[1]	(722)	[2]
Marketable Securities Fair Value 12 Months or Longer	3,300	[1]	2,307	[2]
Marketable Securities Unrealized Losses 12 Months or Longer	(166)	[1]	(228)	[2]
Marketable Securities Fair Value Total	4,798	[1]	8,365	[2]
Marketable Securities Unrealized Losses Total	(196)	[1]	(950)	[2]
Equity Securities
Financial Instruments and Investments [Line Items]
Marketable Securities Fair Value Less than 12 Months	2,146	[1]	3,584	[2]
Marketable Securities Unrealized Losses Less Than 12 Months	(504)	[1]	(344)	[2]
Marketable Securities Fair Value 12 Months or Longer	0	[1]	0	[2]
Marketable Securities Unrealized Losses 12 Months or Longer	0	[1]	0	[2]
Marketable Securities Fair Value Total	2,146	[1]	3,584	[2]
Marketable Securities Unrealized Losses Total	(504)	[1]	(344)	[2]
Institutional Funds-International Equity
Financial Instruments and Investments [Line Items]
Marketable Securities Fair Value Less than 12 Months	21,360	[1]	22,454	[2]
Marketable Securities Unrealized Losses Less Than 12 Months	(1,774)	[1]	(768)	[2]
Marketable Securities Fair Value 12 Months or Longer	0	[1]	0	[2]
Marketable Securities Unrealized Losses 12 Months or Longer	0	[1]	0	[2]
Marketable Securities Fair Value Total	21,360	[1]	22,454	[2]
Marketable Securities Unrealized Losses Total	$ (1,774)	[1]	$ (768)	[2]
[1]	Includes 93 securities.
[2]	Includes 133 securities.

Financial Instruments And Inv41

Financial Instruments And Investments (Unrecognized Gross Unrealized Gains And The Fair Value) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	$ 186,799	$ 140,096
Available-for-sale Securities, Gross Unrealized Gain	39,665	38,366
Debt Securities
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	84,386	40,403
Available-for-sale Securities, Gross Unrealized Gain	4,199	1,274
Collateralized Mortgage Backed Securities
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	17,852	9,589
Available-for-sale Securities, Gross Unrealized Gain	725	438
U.S. Government Bonds
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	37,332	12,033
Available-for-sale Securities, Gross Unrealized Gain	1,670	136
Municipal Bonds
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	11,747	8,671
Available-for-sale Securities, Gross Unrealized Gain	539	332
Corporate Debt Securities
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	17,455	10,110
Available-for-sale Securities, Gross Unrealized Gain	1,265	368
Equity Securities
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	67,574	72,636
Available-for-sale Securities, Gross Unrealized Gain	34,603	37,001
Mutual Funds - Equity
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	29,153	18,853
Available-for-sale Securities, Gross Unrealized Gain	863	91
Cash and Cash Equivalents
Financial Instruments and Investments [Line Items]
Available-for-sale Securities, Unrealized Gain Position, Fair Value	5,686	8,204
Available-for-sale Securities, Gross Unrealized Gain	$ 0	$ 0

Financial Instruments And Inv42

Financial Instruments And Investments (Contractual Year For Maturity Of Available-For-Sale Securities ) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2016USD ($)
Collateralized Mortgage Backed Securities
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	$ 22,785
2,016	711
2017 through 2020	8,957
2021 through 2025	11,727
2026 and Beyond	1,390
Corporate Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Total	22,253
2,016	0
2017 through 2020	4,799
2021 through 2025	8,920
2026 and Beyond	8,534
U.S. Government Bonds
Schedule of Available-for-sale Securities [Line Items]
Total	58,350
2,016	3,404
2017 through 2020	27,172
2021 through 2025	14,676
2026 and Beyond	$ 13,098
Minimum | Collateralized Mortgage Backed Securities
Schedule of Available-for-sale Securities [Line Items]
Debt Instrument, Expected Weighted Average Maturity Year	2 years
Maximum | Collateralized Mortgage Backed Securities
Schedule of Available-for-sale Securities [Line Items]
Debt Instrument, Expected Weighted Average Maturity Year	6 years

Financial Instruments And Inv43

Financial Instruments And Investments (Unrealized Holding Losses Included In Pre-Tax Income) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Financial Instruments And Investments [Abstract]
Unrealized losses included in pre-tax income	$ 0	$ 0	$ (156)	$ 0	$ (494)	$ 0

Financial Instruments And Inv44

Financial Instruments And Investments (Sale Of Securities And The Related Effects On Pre-Tax Income ) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Investment [Line Items]
Proceeds from sales of available-for-sale securities	$ 16,634	$ 12,516	$ 40,712	$ 37,158	$ 106,121	$ 109,095
Gross realized gains included in pre-tax income	2,409	33	4,241	3,815	12,805	8,410
Gross realized losses included in pre-tax income	(299)	(215)	(587)	(252)	(1,262)	(464)
Gross unrealized losses included in pre-tax income	0	0	(156)	0	(494)	0
Net gains (losses) in pre-tax income	2,110	(182)	3,498	3,563	11,049	7,946
Net unrealized holding gains (losses) included in accumulated other comprehensive income	2,790	(1,563)	4,980	(549)	2,623	3,210
Net (gains) losses reclassified out of accumulated other comprehensive income	(2,110)	182	(3,498)	(3,563)	(11,049)	(7,946)
Net gains (losses) in other comprehensive income	$ 680	$ (1,381)	$ 1,482	$ (4,112)	$ (8,426)	$ (4,736)

Financial Instruments And Inv45

Financial Instruments And Investments (Company's Decommissioning Trust Funds And Investments In Debt Securities) (Details) - USD ($) $ in Thousands		Jun. 30, 2016	Dec. 31, 2015
Decommisioning Fund Investments
Financial Instruments and Investments [Line Items]
Available-for-sale Securities		$ 248,240	$ 239,035
Decommisioning Fund Investments | Quoted Prices In Active Markets For Identical Assets (Level 1)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities		162,909	153,676
Decommisioning Fund Investments | Significant Other Observable Inputs (Level 2)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities		63,971	62,905
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]
Trading Securities		1,376	1,543
Debt Securities | Quoted Prices In Active Markets For Identical Assets (Level 1)
Financial Instruments and Investments [Line Items]
Trading Securities		0	0
Debt Securities | Significant Other Observable Inputs (Level 2)
Financial Instruments and Investments [Line Items]
Trading Securities		0	0
Debt Securities | Significant Unobservable Inputs (Level 3)
Financial Instruments and Investments [Line Items]
Trading Securities		1,376	1,543
Debt Securities | Decommisioning Fund Investments
Financial Instruments and Investments [Line Items]
Available-for-sale Securities		122,321	113,304
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		58,350	50,399
Debt Securities | Decommisioning Fund Investments | Significant Other Observable Inputs (Level 2)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities		63,971	62,905
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		58,350	50,399
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		58,350	50,399
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		18,933	20,085
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		18,933	20,085
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		22,785	24,345
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		22,785	24,345
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		22,253	18,475
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		22,253	18,475
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		69,720	76,220
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		69,720	76,220
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
Equity Funds | Decommisioning Fund Investments
Financial Instruments and Investments [Line Items]
Available-for-sale Securities		29,153	18,853
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		29,153	18,853
Equity Funds | Decommisioning Fund Investments | Significant Other Observable Inputs (Level 2)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities		0	0
Equity Funds | Decommisioning Fund Investments | Significant Unobservable Inputs (Level 3)
Financial Instruments and Investments [Line Items]
Available-for-sale Securities		0	0
Institutional Funds-International Equity | Decommisioning Fund Investments
Financial Instruments and Investments [Line Items]
Available-for-sale Securities	[1]	21,360	22,454
Cash and Cash Equivalents | Decommisioning Fund Investments
Financial Instruments and Investments [Line Items]
Available-for-sale Securities		5,686	8,204
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		5,686	8,204
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
[1]	In accordance with ASU 2015-07 Subtopic 820-10, certain investments that are measured at fair value using the NAV per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair value amounts presented in the table are intended to permit reconciliation of the fair value hierarchy to the amounts presented in the statement of financial position.

Financial Instruments And Inv46

Financial Instruments And Investments Transfers Between Levels (Details) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Fair Value Disclosures [Abstract]
Fair Value, Assets, Level 1 to Level 2 Transfers, Description	no	no	no	no	no	no
Fair Value, Assets, Level 2 to Level 1 Transfers, Description	no	no	no	no	no	no
Fair Value, Asset, Level 3 Purchases, (Sales), Issuances, (Settlements)	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0