Document and Entity Information
Document and Entity Information - shares | 9 Months Ended | |
Sep. 30, 2015 | Oct. 28, 2015 | |
Document And Entity Information [Abstract] | ||
Document Type | 10-Q | |
Amendment Flag | false | |
Document Period End Date | Sep. 30, 2015 | |
Document Fiscal Year Focus | 2,015 | |
Document Fiscal Period Focus | Q3 | |
Trading Symbol | SWX | |
Entity Registrant Name | SOUTHWEST GAS CORP | |
Entity Central Index Key | 92,416 | |
Current Fiscal Year End Date | --12-31 | |
Entity Filer Category | Large Accelerated Filer | |
Entity Common Stock, Shares Outstanding | 47,375,398 |
Condensed Consolidated Balance
Condensed Consolidated Balance Sheets - USD ($) $ in Thousands | Sep. 30, 2015 | Dec. 31, 2014 |
Utility plant: | ||
Gas plant | $ 5,734,807 | $ 5,556,599 |
Less: accumulated depreciation | (2,060,402) | (1,973,098) |
Acquisition adjustments, net | 415 | 550 |
Construction work in progress | 118,554 | 74,332 |
Net utility plant | 3,793,374 | 3,658,383 |
Other property and investments | 319,243 | 326,743 |
Restricted cash | 0 | 821 |
Current assets: | ||
Cash and cash equivalents | 32,959 | 39,566 |
Accounts receivable, net of allowances | 269,058 | 281,824 |
Accrued utility revenue | 32,200 | 73,900 |
Income taxes receivable, net | 37,810 | 21,853 |
Deferred income taxes, net | 291 | 2,109 |
Deferred purchased gas costs | 815 | 87,556 |
Prepaids and other current assets | 105,438 | 99,975 |
Total current assets | 478,571 | 606,783 |
Noncurrent assets: | ||
Goodwill | 129,884 | 143,160 |
Deferred income taxes | 1,688 | 0 |
Deferred charges and other assets | 460,906 | 478,625 |
Total noncurrent assets | 592,478 | 621,785 |
Total assets | 5,183,666 | 5,214,515 |
Capitalization: | ||
Common stock, $1 par (authorized-60,000,000 shares; issued and outstanding-47,375,398 and 46,523,184 shares) | 49,005 | 48,153 |
Additional paid-in capital | 894,625 | 851,381 |
Accumulated other comprehensive income (loss), net | (48,013) | (50,175) |
Retained earnings | 654,492 | 639,164 |
Total Southwest Gas Corporation equity | 1,550,109 | 1,488,523 |
Noncontrolling interest | (2,177) | (2,257) |
Total equity | 1,547,932 | 1,486,266 |
Redeemable noncontrolling interest | 13,703 | 20,042 |
Long-term debt, less current maturities | 1,540,364 | 1,637,592 |
Total capitalization | 3,101,999 | 3,143,900 |
Current liabilities: | ||
Current maturities of long-term debt | 19,865 | 19,192 |
Short-term debt | 0 | 5,000 |
Accounts payable | 129,258 | 167,988 |
Customer deposits | 72,268 | 71,546 |
Income taxes payable | 13,643 | 0 |
Accrued general taxes | 42,249 | 44,339 |
Accrued interest | 21,730 | 16,468 |
Deferred income taxes | 7,031 | 0 |
Deferred purchased gas costs | 44,754 | 0 |
Other current liabilities | 143,882 | 145,584 |
Total current liabilities | 494,680 | 470,117 |
Deferred income taxes and other credits: | ||
Deferred income taxes and investment tax credits | 722,718 | 723,688 |
Accumulated removal costs | 301,000 | 304,000 |
Other deferred credits and other long-term liabilities | 563,269 | 572,810 |
Total deferred income taxes and other credits | 1,586,987 | 1,600,498 |
Total capitalization and liabilities | $ 5,183,666 | $ 5,214,515 |
Condensed Consolidated Balance3
Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares | Sep. 30, 2015 | Dec. 31, 2014 |
Statement of Financial Position [Abstract] | ||
Common stock, par | $ 1 | $ 1 |
Common stock, authorized | 60,000,000 | 60,000,000 |
Common stock, issued | 47,375,398 | 46,523,184 |
Common stock, outstanding | 47,375,398 | 46,523,184 |
Condensed Consolidated Statemen
Condensed Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands | 3 Months Ended | 9 Months Ended | 12 Months Ended | |||
Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | |
Operating revenues: | ||||||
Gas operating revenues | $ 219,420 | $ 226,027 | $ 1,059,178 | $ 983,999 | $ 1,457,266 | $ 1,356,653 |
Construction revenues | 285,976 | 206,448 | 719,042 | 510,025 | 948,637 | 675,728 |
Total operating revenues | 505,396 | 432,475 | 1,778,220 | 1,494,024 | 2,405,903 | 2,032,381 |
Operating expenses: | ||||||
Net cost of gas sold | 64,268 | 72,987 | 427,045 | 362,349 | 570,052 | 480,608 |
Operations and maintenance | 100,102 | 93,389 | 294,956 | 293,417 | 385,271 | 390,328 |
Depreciation and amortization | 66,476 | 62,037 | 200,898 | 187,114 | 266,811 | 247,684 |
Taxes other than income taxes | 11,652 | 11,835 | 37,063 | 34,256 | 50,059 | 45,786 |
Construction expenses | 246,755 | 173,937 | 647,512 | 444,778 | 850,591 | 595,093 |
Total operating expenses | 489,253 | 414,185 | 1,607,474 | 1,321,914 | 2,122,784 | 1,759,499 |
Operating income | 16,143 | 18,290 | 170,746 | 172,110 | 283,119 | 272,882 |
Other income and (expenses): | ||||||
Net interest deductions | (18,401) | (17,421) | (54,095) | (52,245) | (73,919) | (69,680) |
Other income (deductions) | (3,660) | 440 | (1,226) | 4,915 | 966 | 9,026 |
Total other income and (expenses) | (22,061) | (16,981) | (55,321) | (47,330) | (72,953) | (60,654) |
Income (loss) before income taxes | (5,918) | 1,309 | 115,425 | 124,780 | 210,166 | 212,228 |
Income tax expense (benefit) | (1,708) | (618) | 42,693 | 42,529 | 78,537 | 72,788 |
Net income (loss) | (4,210) | 1,927 | 72,732 | 82,251 | 131,629 | 139,440 |
Net income (loss) attributable to noncontrolling interests | 524 | (43) | 534 | (129) | 685 | (243) |
Net income (loss) attributable to Southwest Gas Corporation | $ (4,734) | $ 1,970 | $ 72,198 | $ 82,380 | $ 130,944 | $ 139,683 |
Basic earnings (loss) per share | $ (0.10) | $ 0.04 | $ 1.54 | $ 1.77 | $ 2.80 | $ 3.01 |
Diluted earnings (loss) per share | (0.10) | 0.04 | 1.53 | 1.76 | 2.77 | 2.98 |
Dividends declared per share | $ 0.405 | $ 0.365 | $ 1.215 | $ 1.095 | $ 1.580 | $ 1.425 |
Average number of common shares outstanding | 47,102 | 46,513 | 46,863 | 46,485 | 46,777 | 46,451 |
Average shares outstanding (assuming dilution) | 0 | 46,966 | 47,261 | 46,928 | 47,194 | 46,904 |
Condensed Consolidated Stateme5
Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | 12 Months Ended | |||
Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | |
Statement of Comprehensive Income [Abstract] | ||||||
Net income (loss) | $ (4,210) | $ 1,927 | $ 72,732 | $ 82,251 | $ 131,629 | $ 139,440 |
Defined benefit pension plans: | ||||||
Net actuarial gain (loss) | 0 | 0 | 0 | 0 | (107,661) | 62,214 |
Amortization of prior service cost | 207 | 55 | 621 | 165 | 676 | 221 |
Amortization of net actuarial loss | 5,329 | 3,667 | 15,987 | 11,000 | 19,654 | 16,297 |
Prior service cost | 0 | 0 | 0 | 0 | (4,130) | 0 |
Regulatory adjustment | (4,828) | (3,210) | (14,484) | (9,630) | 82,137 | (72,176) |
Net defined benefit pension plans | 708 | 512 | 2,124 | 1,535 | (9,324) | 6,556 |
Forward-starting interest rate swaps: | ||||||
Amounts reclassified into net income | 519 | 518 | 1,556 | 1,555 | 2,074 | 2,074 |
Net forward-starting interest rate swaps | 519 | 518 | 1,556 | 1,555 | 2,074 | 2,074 |
Foreign currency translation adjustments | (510) | 0 | (1,573) | 0 | (2,232) | 0 |
Total other comprehensive income (loss), net of tax | 717 | 1,030 | 2,107 | 3,090 | (9,482) | 8,630 |
Comprehensive income (loss) | (3,493) | 2,957 | 74,839 | 85,341 | 122,147 | 148,070 |
Comprehensive income (loss) attributable to noncontrolling interests | 504 | (43) | 479 | (129) | 608 | (243) |
Comprehensive income (loss) attributable to Southwest Gas Corporation | $ (3,997) | $ 3,000 | $ 74,360 | $ 85,470 | $ 121,539 | $ 148,313 |
Condensed Consolidated Stateme6
Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands | 9 Months Ended | 12 Months Ended | ||
Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | |
CASH FLOW FROM OPERATING ACTIVITIES: | ||||
Net income | $ 72,732 | $ 82,251 | $ 131,629 | $ 139,440 |
Adjustments to reconcile net income to net cash provided by operating activities: | ||||
Depreciation and amortization | 200,898 | 187,114 | 266,811 | 247,684 |
Deferred income taxes | 5,961 | 37,690 | 32,580 | 62,625 |
Changes in current assets and liabilities: | ||||
Accounts receivable, net of allowances | 6,570 | 34,679 | (31,792) | (29,187) |
Accrued utility revenue | 41,700 | 40,700 | (200) | (700) |
Deferred purchased gas costs | 131,495 | (60,101) | 122,257 | (92,535) |
Accounts payable | (38,878) | (85,514) | 5,137 | (3,029) |
Accrued taxes | (4,427) | (16,869) | (1,131) | (14,704) |
Other current assets and liabilities | 8,333 | 43,650 | (11,938) | 20,941 |
Gains on sale | (3,019) | (5,661) | (3,529) | (6,783) |
Changes in undistributed stock compensation | 2,119 | 4,612 | 5,480 | 6,126 |
AFUDC | (2,011) | (1,571) | (2,435) | (2,187) |
Changes in other assets and deferred charges | (14,423) | (17,420) | (18,735) | (16,685) |
Changes in other liabilities and deferred credits | 5,348 | 18,344 | 2,783 | 28,569 |
Net cash provided by operating activities | 412,398 | 261,904 | 496,917 | 339,575 |
CASH FLOW FROM INVESTING ACTIVITIES: | ||||
Construction expenditures and property additions | (336,569) | (293,276) | (440,191) | (403,115) |
Acquisition of businesses, net of cash acquired | (9,261) | 0 | (199,758) | 0 |
Restricted cash | 785 | 0 | 2,018 | 0 |
Changes in customer advances | 14,300 | 13,124 | 21,539 | 15,694 |
Miscellaneous inflows | 11,593 | 9,780 | 13,424 | 11,838 |
Miscellaneous outflows | 0 | 0 | (1,400) | 0 |
Net cash used in investing activities | (319,152) | (270,372) | (604,368) | (375,583) |
CASH FLOW FROM FINANCING ACTIVITIES: | ||||
Issuance of common stock, net | 35,419 | 419 | 35,405 | 608 |
Dividends paid | (55,060) | (49,295) | (72,040) | (64,592) |
Issuance of long-term debt, net | 123,816 | 37,719 | 355,325 | 285,336 |
Retirement of long-term debt | (143,325) | (21,528) | (260,952) | (28,272) |
Change in credit facility and commercial paper | (53,000) | 40,000 | 47,000 | (100,000) |
Change in short-term debt | (5,000) | 0 | 0 | (33,000) |
Principal payments on capital lease obligations | (1,096) | 0 | (1,530) | 0 |
Other | (504) | (759) | (1,002) | 1,240 |
Net cash provided by (used in) financing activities | (98,750) | 6,556 | 102,206 | 61,320 |
Effects of currency translation on cash and cash equivalents | (1,103) | 0 | (961) | 0 |
Change in cash and cash equivalents | (6,607) | (1,912) | (6,206) | 25,312 |
Cash and cash equivalents at beginning of period | 39,566 | 41,077 | 39,165 | 13,853 |
Cash and cash equivalents at end of period | 32,959 | 39,165 | 32,959 | 39,165 |
Supplemental information: | ||||
Interest paid, net of amounts capitalized | 45,312 | 42,695 | 68,169 | 60,264 |
Income taxes paid | $ 39,856 | $ 14,823 | $ 49,280 | $ 16,744 |
Nature of Operations and Basis
Nature of Operations and Basis of Presentation | 9 Months Ended |
Sep. 30, 2015 | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
Nature of Operations and Basis of Presentation | Note 1 – Nature of Operations and Basis of Presentation Nature of Operations. Basis of Presentation. Centuri, through its subsidiaries, holds a 50% interest in W.S. Nicholls Western Construction LTD. (“Western”), a Canadian construction services company that is a variable interest entity. Centuri determined that it is not the primary beneficiary of the entity due to a shared-power structure; therefore, Centuri does not consolidate the entity and has recorded its investment, and results related thereto, using the equity method. The Company’s investment in Western is not significant in relation to its total assets included in the Condensed Consolidated Balance Sheets. Prepaids and other current assets. Cash and Cash Equivalents. Significant non-cash investing and financing activities for the natural gas operations segment included the following: Upon contract expiration, customer advances of approximately $2.8 million and $7 million, during the first nine months of 2015 and 2014, respectively, were applied as contributions toward utility construction activity and represent non-cash investing activity. Goodwill. Therefore, goodwill assigned to Brigadier is expected to be deductible for tax purposes, resulting in an after-tax value of $4.9 million. All other goodwill associated with the acquisition is not deductible for tax purposes. (In thousands of dollars) Natural Gas Construction Consolidated December 31, 2014 $ 10,095 $ 133,065 $ 143,160 Acquisition date adjustment — 1,380 1,380 Foreign currency translation adjustment — (14,656 ) (14,656 ) September 30, 2015 $ 10,095 $ 119,789 $ 129,884 Intercompany Transactions Note 3—Segment Information September 30, December 31, Centuri accounts receivable for services provided to Southwest $ 15,972 $ 9,169 The accounts receivable balance, revenues, and associated profits are included in the condensed consolidated financial statements of the Company and were not eliminated during consolidation in accordance with accounting treatment for rate-regulated entities. Other Property and Investments. September 30, December 31, Centuri property and equipment $ 419 $ 405 Centuri accumulated provision for depreciation and amortization (209 ) (187 ) Net cash surrender value of COLI policies 97 99 Other property 12 10 Total $ 319 $ 327 Other Income (Deductions). Three Months Ended Nine Months Ended Twelve Months Ended September 30 September 30 September 30 2015 2014 2015 2014 2015 2014 Change in COLI policies $ (3,900 ) $ (300 ) $ (2,600 ) $ 2,900 $ (200 ) $ 7,200 Interest income 624 772 1,375 1,881 2,096 1,920 Foreign transaction gain (loss) (302 ) — (874 ) — (1,052 ) — Miscellaneous income and (expense) (82 ) (32 ) 873 134 122 (94 ) Total other income (deductions) $ (3,660 ) $ 440 $ (1,226 ) $ 4,915 $ 966 $ 9,026 Included in the table above is the change in cash surrender values of company-owned life insurance (“COLI”) policies (including net death benefits recognized). These life insurance policies on members of management and other key employees are used by Southwest to indemnify itself against the loss of talent, expertise, and knowledge, as well as to provide indirect funding for certain nonqualified benefit plans. Current tax regulations provide for tax-free treatment of life insurance (death benefit) proceeds. Therefore, changes in the cash surrender values of COLI policies, as they progress towards the ultimate death benefits, are also recorded without tax consequences. Recently Issued Accounting Standards Updates. In August 2014, the FASB issued the update “Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern,” which requires management to assess a company’s ability to continue as a going concern and to provide related footnote disclosures in certain circumstances. Under the update, disclosures are required when conditions give rise to substantial doubt about a company’s ability to continue as a going concern within one year from the financial statement issuance date. The update is effective for the annual period ending after December 15, 2016, and all annual and interim periods thereafter. This update is not expected to have a material impact on the Company’s disclosures. In April 2015, the FASB issued the update “Interest—Imputation of Interest (Subtopic 835-30) Simplifying the Presentation of Debt Issuance Costs.” To simplify presentation of debt issuance costs, the amendments in this update require 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 the amendments in this update. Retrospective application of the update is required. The amendments in this update are effective for financial statements issued for fiscal years beginning after December 15, 2015, and interim periods within fiscal years beginning after December 15, 2016. Early adoption of the amendments in this update is permitted for financial statements that have not been previously issued. This update is not expected to have a material impact on the Company’s consolidated financial statements and disclosures. |
Components of Net Periodic Bene
Components of Net Periodic Benefit Cost | 9 Months Ended |
Sep. 30, 2015 | |
Text Block [Abstract] | |
Components of Net Periodic Benefit Cost | Note 2 – Components of Net Periodic Benefit Cost Southwest has a noncontributory qualified retirement plan with defined benefits covering substantially all employees and a separate unfunded supplemental retirement plan (“SERP”) which is limited to officers. Southwest also provides postretirement benefits other than pensions (“PBOP”) to its qualified retirees for health care, dental, and life insurance. Net periodic benefit costs included in the table below are components of an overhead loading process associated with the cost of labor. The overhead process ultimately results in allocation of net periodic benefit costs to the same accounts to which productive labor is charged. As a result, net periodic benefit costs become components of various accounts, primarily operations and maintenance expense, net utility plant, and deferred charges and other assets. Qualified Retirement Plan Period Ended September 30, Three Months Nine Months Twelve Months 2015 2014 2015 2014 2015 2014 (Thousands of dollars) Service cost $ 6,281 $ 5,340 $ 18,842 $ 16,020 $ 24,182 $ 21,784 Interest cost 11,057 10,860 33,172 32,581 44,031 41,983 Expected return on plan assets (14,452 ) (13,336 ) (43,356 ) (40,007 ) (56,691 ) (52,467 ) Amortization of net actuarial loss 8,186 5,718 24,557 17,154 30,276 25,219 Net periodic benefit cost $ 11,072 $ 8,582 $ 33,215 $ 25,748 $ 41,798 $ 36,519 SERP Period Ended September 30, Three Months Nine Months Twelve Months 2015 2014 2015 2014 2015 2014 (Thousands of dollars) Service cost $ 80 $ 73 $ 240 $ 219 $ 313 $ 312 Interest cost 424 436 1,271 1,308 1,708 1,692 Amortization of net actuarial loss 323 196 970 588 1,165 830 Net periodic benefit cost $ 827 $ 705 $ 2,481 $ 2,115 $ 3,186 $ 2,834 PBOP Period Ended September 30, Three Months Nine Months Twelve Months 2015 2014 2015 2014 2015 2014 (Thousands of dollars) Service cost $ 410 $ 275 $ 1,231 $ 826 $ 1,506 $ 1,131 Interest cost 750 707 2,249 2,122 2,956 2,743 Expected return on plan assets (866 ) (816 ) (2,598 ) (2,448 ) (3,414 ) (3,154 ) Amortization of prior service costs 334 89 1,001 266 1,090 355 Amortization of net actuarial loss 86 — 259 — 259 236 Net periodic benefit cost $ 714 $ 255 $ 2,142 $ 766 $ 2,397 $ 1,311 |
Segment Information
Segment Information | 9 Months Ended |
Sep. 30, 2015 | |
Segment Reporting [Abstract] | |
Segment Information | Note 3 – Segment Information The following tables present revenues from external customers, intersegment revenues, and segment net income (thousands of dollars): Natural Gas Construction Total Three months ended September 30, 2015 Revenues from external customers $ 219,420 $ 255,088 $ 474,508 Intersegment revenues — 30,888 30,888 Total $ 219,420 $ 285,976 $ 505,396 Segment net income (loss) $ (18,939 ) $ 14,205 $ (4,734 ) Three months ended September 30, 2014 Revenues from external customers $ 226,027 $ 183,290 $ 409,317 Intersegment revenues — 23,158 23,158 Total $ 226,027 $ 206,448 $ 432,475 Segment net income (loss) $ (11,452 ) $ 13,422 $ 1,970 Natural Gas Construction Total Nine months ended September 30, 2015 Revenues from external customers $ 1,059,178 $ 645,289 $ 1,704,467 Intersegment revenues — 73,753 73,753 Total $ 1,059,178 $ 719,042 $ 1,778,220 Segment net income $ 59,325 $ 12,873 $ 72,198 Nine months ended September 30, 2014 Revenues from external customers $ 983,999 $ 438,409 $ 1,422,408 Intersegment revenues — 71,616 71,616 Total $ 983,999 $ 510,025 $ 1,494,024 Segment net income $ 62,945 $ 19,435 $ 82,380 Natural Gas Construction Total Twelve months ended September 30, 2015 Revenues from external customers $ 1,457,266 $ 854,312 $ 2,311,578 Intersegment revenues — 94,325 94,325 Total $ 1,457,266 $ 948,637 $ 2,405,903 Segment net income $ 113,252 $ 17,692 $ 130,944 Twelve months ended September 30, 2014 Revenues from external customers $ 1,356,653 $ 577,384 $ 1,934,037 Intersegment revenues — 98,344 98,344 Total $ 1,356,653 $ 675,728 $ 2,032,381 Segment net income $ 117,797 $ 21,886 $ 139,683 |
Derivatives and Fair Value Meas
Derivatives and Fair Value Measurements | 9 Months Ended |
Sep. 30, 2015 | |
Derivative Instruments and Hedging Activities Disclosure [Abstract] | |
Derivatives and Fair Value Measurements | Note 4 – Derivatives and Fair Value Measurements Derivatives. The fixed-price contracts and Swaps are utilized by Southwest under its volatility mitigation programs to effectively fix the price on a portion (up to 25% in the Arizona and California jurisdictions) of its natural gas supply portfolios. The maturities of the Swaps highly correlate to forecasted purchases of natural gas, during time frames ranging from October 2015 through March 2017. Under such contracts, Southwest pays the counterparty at a fixed rate and receives from the counterparty a floating rate per MMBtu (“dekatherm”) of natural gas. Only the net differential is actually paid or received. The differential is calculated based on the notional amounts under the contracts, which are detailed in the table below (thousands of dekatherms): September 30, December 31, Contract notional amounts 8,192 5,105 In late 2013, the Company suspended further Swaps and fixed-price purchases pursuant to the Volatility Mitigation Program (“VMP”) for its Nevada service territories. The decision did not impact previously executed purchase arrangements. Agreements, under the Nevada VMP, made prior to the suspension, terminated following the March 2015 delivery month. The Company, along with its regulators, will continue to evaluate this strategy in light of prevailing or anticipated changing market conditions. Southwest does not utilize derivative financial instruments for speculative purposes, nor does it have trading operations. The following table sets forth the gains and (losses) recognized on the Company’s Swaps (derivatives) for the three-, nine-, and twelve-month periods ended September 30, 2015 and 2014 and their location in the Condensed Consolidated Statements of Income: Gains (losses) recognized in income for derivatives not designated as hedging instruments: (Thousands of dollars) Location of Gain or (Loss) Three Months Ended Nine Months Ended Twelve Months Ended September 30 September 30 September 30 Instrument 2015 2014 2015 2014 2015 2014 Swaps Net cost of gas sold $ (3,282 ) $ (2,277 ) $ (4,689 ) $ 3,630 $ (10,682 ) $ 7,552 Swaps Net cost of gas sold 3,282 * 2,277 * 4,689 * (3,630 )* 10,682 * (7,552 )* Total $ — $ — $ — $ — $ — $ — * Represents the impact of regulatory deferral accounting treatment under U.S. GAAP for rate-regulated entities. No gains (losses) were recognized in income or other comprehensive income during the periods presented for derivatives designated as cash flow hedging instruments. Previously, Southwest entered into two forward-starting interest rate swaps (“FSIRS”), both of which were designated cash flow hedges, to partially hedge the risk of interest rate variability during the period leading up to the issuance of debt. The first FSIRS terminated in December 2010. The second FSIRS terminated in March 2012. Losses on both FSIRS are being amortized over ten-year periods from Accumulated other comprehensive income (loss) and into interest expense. The following table sets forth the fair values of the Company’s Swaps and their location in the Condensed Consolidated Balance Sheets (thousands of dollars): Fair values of derivatives not designated as hedging instruments: September 30, 2015 Asset Derivatives Liability Derivatives Net Total Instrument Balance Sheet Location Swaps Other current liabilities $ — $ (3,425 ) $ (3,425 ) Swaps Other deferred credits — (1,462 ) (1,462 ) Total $ — $ (4,887 ) $ (4,887 ) December 31, 2014 Asset Derivatives Liability Derivatives Net Total Instrument Balance Sheet Location Swaps Other current liabilities $ — $ (5,062 ) $ (5,062 ) Swaps Other deferred credits — (363 ) (363 ) Total $ — $ (5,425 ) $ (5,425 ) The estimated fair values of the natural gas derivatives were determined using future natural gas index prices (as more fully described below). The Company has master netting arrangements with each counterparty that provide for the net settlement of all contracts through a single payment. As applicable, the Company has elected to reflect the net amounts in its balance sheets. The Company had no outstanding collateral associated with the Swaps during either period shown in the above table. Pursuant to regulatory deferral accounting treatment for rate-regulated entities, Southwest records the unrealized gains and losses in fair value of the Swaps as a regulatory asset and/or liability. When the Swaps mature, Southwest reverses any prior positions held and records the settled position as an increase or decrease in purchased gas under the related purchased gas adjustment (“PGA”) mechanism in determining its deferred PGA balances. Neither changes in fair value, nor settled amounts, of Swaps have a direct effect on earnings or other comprehensive income. The following table shows the amounts Southwest paid to and received from counterparties for settlements of matured Swaps. Three Months Ended Nine Months Ended Twelve Months Ended (Thousands of dollars) September 30, 2015 September 30, 2015 September 30, 2015 Paid to counterparties $ 568 $ 5,228 $ 5,971 Received from counterparties $ — $ — $ 120 The following table details the regulatory assets/(liabilities) offsetting the derivatives at fair value in the Condensed Consolidated Balance Sheets (thousands of dollars). September 30, 2015 Instrument Balance Sheet Location Net Total Swaps Prepaids and other current assets $ 3,425 Swaps Deferred charges and other assets 1,462 December 31, 2014 Instrument Balance Sheet Location Net Total Swaps Prepaids and other current assets $ 5,062 Swaps Deferred charges and other assets 363 Fair Value Measurements. The following table sets forth by level within the three-level fair value hierarchy that ranks the inputs used to measure fair value by their reliability, the Company’s financial assets and liabilities that were accounted for at fair value: Level 2—Significant other observable inputs (Thousands of dollars) September 30, December 31, Liabilities at fair value: Other current liabilities—Swaps $ (3,425 ) $ (5,062 ) Other deferred credits—Swaps (1,462 ) (363 ) Net Assets (Liabilities) $ (4,887 ) $ (5,425 ) No financial assets or liabilities accounted for at fair value fell within Level 1 (quoted prices in active markets for identical financial assets) or Level 3 (significant unobservable inputs) of the fair value hierarchy. With regard to the fair values of assets associated with the Company’s pension and postretirement benefit plans, asset values were last updated as required as of December 2014. Refer to Note 9 – Pension and Other Post Retirement Benefits in the 2014 Annual Report to Shareholders on Form 10-K. |
Common Stock
Common Stock | 9 Months Ended |
Sep. 30, 2015 | |
Text Block [Abstract] | |
Common Stock | Note 5 – Common Stock On March 10, 2015, the Company filed with the Securities Exchange Commission (“SEC”) an automatic shelf registration statement on Form S-3 (File No. 333-202633), which became effective upon filing, for the offer and sale of up to $100,000,000 of the Company’s common stock from time to time in at-the-market offerings under the prospectus included therein and in accordance with the Sales Agency Agreement, dated March 10, 2015, between the Company and BNY Mellon Capital Markets, LLC (the “Equity Shelf Program”). During the three months ending September 30, 2015, the Company sold, through the continuous equity offering program with BNY Mellon Capital Markets, LLC as agent, an aggregate of 272,716 shares of the Company’s common stock in the open market at a weighted average price of $54.12 per share, resulting in proceeds to the Company of $14,610,439, net of $147,579 in agent commissions. For the nine months ended September 30, 2015, the Company sold an aggregate of 645,225 shares of common stock under this program resulting in proceeds to the Company of $35,167,584, net of $355,228 in agent commissions. As of September 30, 2015, the Company had up to $64,477,188 of common stock available for sale under the program. Net proceeds from the sale of shares of common stock under the Equity Shelf Program are intended for general corporate purposes, including the acquisition of property for the construction, completion, extension or improvement of pipeline systems and facilities located in and around the communities Southwest serves. In addition, during the nine months ended September 30, 2015, the Company issued approximately 207,000 shares of common stock through the Stock Incentive Plan, Restricted Stock/Unit Plan, and Management Incentive Plan. |
Long-Term Debt
Long-Term Debt | 9 Months Ended |
Sep. 30, 2015 | |
Debt Disclosure [Abstract] | |
Long-Term Debt | Note 6 – Long-Term Debt Carrying amounts of the Company’s long-term debt and their related estimated fair values as of September 30, 2015 and December 31, 2014 are disclosed in the following table. The fair values of the revolving credit facility (including commercial paper) and the variable-rate Industrial Development Revenue Bonds (“IDRBs”) approximate their carrying values, as they are repaid quickly (in the case of credit facility borrowings) and have interest rates that reset frequently. They are categorized as Level 1 (quoted prices for identical financial instruments) within the three-level September 30, 2015 December 31, 2014 Carrying Market Carrying Market (Thousands of dollars) Debentures: Notes, 4.45%, due 2020 $ 125,000 $ 132,769 $ 125,000 $ 133,403 Notes, 6.1%, due 2041 125,000 147,451 125,000 157,290 Notes, 3.875%, due 2022 250,000 263,023 250,000 262,030 Notes, 4.875%, due 2043 250,000 266,370 250,000 280,903 8% Series, due 2026 75,000 99,380 75,000 102,296 Medium-term notes, 7.59% series, due 2017 25,000 26,662 25,000 27,573 Medium-term notes, 7.78% series, due 2022 25,000 30,621 25,000 31,144 Medium-term notes, 7.92% series, due 2027 25,000 32,726 25,000 33,695 Medium-term notes, 6.76% series, due 2027 7,500 8,917 7,500 9,156 Unamortized discount (4,957 ) (5,223 ) 902,543 902,277 Revolving credit facility and commercial paper 97,000 97,000 150,000 150,000 Industrial development revenue bonds: Variable-rate bonds: Tax-exempt Series A, due 2028 50,000 50,000 50,000 50,000 2003 Series A, due 2038 50,000 50,000 50,000 50,000 2008 Series A, due 2038 50,000 50,000 50,000 50,000 2009 Series A, due 2039 50,000 50,000 50,000 50,000 Fixed-rate bonds: 5.25% 2003 Series D, due 2038 — — 20,000 20,277 5.00% 2004 Series B, due 2033 — — 31,200 31,223 4.85% 2005 Series A, due 2035 100,000 100,415 100,000 100,071 4.75% 2006 Series A, due 2036 24,855 25,089 24,855 25,399 Unamortized discount (1,539 ) (1,943 ) 323,316 374,112 Centuri secured revolving credit and term loan facility 208,787 209,213 199,267 200,341 Centuri other debt obligations 28,583 28,868 31,128 31,127 1,560,229 1,656,784 Less: current maturities (19,865 ) (19,192 ) Long-term debt, less current maturities $ 1,540,364 $ 1,637,592 In March 2015, the Company amended its $300 million credit facility. The facility was previously scheduled to expire in March 2019 and was extended to March 2020. The Company will continue to use $150 million of the facility as long-term debt and the remaining $150 million for working capital purposes. Interest rates for the credit facility are calculated at either the London Interbank Offered Rate (“LIBOR”) or an “alternate base rate,” plus in each case an applicable margin that is determined based on the Company’s senior unsecured debt rating. At September 30, 2015, the applicable margin is 1% for loans bearing interest with reference to LIBOR and 0% for loans bearing interest with reference to the alternative base rate. At September 30, 2015, $47 million was outstanding on the credit facility and $50 million was outstanding on the commercial paper program. In May 2015, the Company redeemed at par the $31.2 million 5.00% 2004 Series B IDRBs originally due in 2033. The Company facilitated the redemption primarily from cash on hand and borrowings under its $300 million credit facility. In September 2015, the Company redeemed at par the $20 million 5.25% 2003 Series D IDRBs originally due in 2038. The Company facilitated the redemption primarily from cash on hand and borrowings under its $300 million credit facility. Centuri has a $300 million secured revolving credit and term loan facility that is scheduled to expire in October 2019. At September 30, 2015, $209 million in borrowings were outstanding on the Centuri facility. Centuri assets securing the facility at September 30, 2015 totaled $557 million. |
Equity, Other Comprehensive Inc
Equity, Other Comprehensive Income, and Accumulated Other Comprehensive Income | 9 Months Ended |
Sep. 30, 2015 | |
Equity [Abstract] | |
Equity, Other Comprehensive Income, and Accumulated Other Comprehensive Income | Note 7 – Equity, Other Comprehensive Income, and Accumulated Other Comprehensive Income The table below provides details of activity in equity and the redeemable noncontrolling interest during the nine months ended September 30, 2015. Southwest Gas Corporation Equity Additional Paid-in Capital Accumulated Comprehensive Income (Loss) Redeemable Interest (Temporary Common Stock Retained Non-controlling (In thousands except per share amounts) Shares Amount Total DECEMBER 31, 2014 46,523 $ 48,153 $ 851,381 $ (50,175 ) $ 639,164 $ (2,257 ) $ 1,486,266 $ 20,042 Common stock issuances 852 852 37,467 38,319 Net income (loss) 72,198 80 72,278 454 Redemption value adjustments 5,777 961 6,738 (6,738 ) Foreign currency exchange translation adj. (1,518 ) (1,518 ) (55 ) Other comprehensive income (loss): Net actuarial gain (loss) arising during period, less amortization of unamortized benefit plan cost, net of tax 2,124 2,124 Amounts reclassified to net income, net of tax (FSIRS) 1,556 1,556 Dividends declared Common: $1.215 per share (57,831 ) (57,831 ) SEPTEMBER 30, 2015 47,375 $ 49,005 $ 894,625 $ (48,013 ) $ 654,492 $ (2,177 ) $ 1,547,932 $ 13,703 The following information provides insight into amounts impacting Other Comprehensive Income (Loss), both before and after-tax, within the Condensed Consolidated Statements of Comprehensive Income, which also impact Accumulated Other Comprehensive Income in the Company’s Condensed Consolidated Balance Sheets and the associated column in the equity table above. See Note 4 – Derivatives and Fair Value Measurements Related Tax Effects Allocated to Each Component of Other Comprehensive Income (Loss) (Thousands of dollars) Three Months Ended September 30, 2015 Three Months Ended September 30, 2014 Before- Tax Net-of- Before- Tax Net-of- Defined benefit pension plans: Amortization of prior service cost $ 334 $ (127 ) $ 207 $ 89 $ (34 ) $ 55 Amortization of net actuarial (gain)/loss 8,595 (3,266 ) 5,329 5,914 (2,247 ) 3,667 Regulatory adjustment (7,787 ) 2,959 (4,828 ) (5,178 ) 1,968 (3,210 ) Pension plans other comprehensive income (loss) 1,142 (434 ) 708 825 (313 ) 512 FSIRS (designated hedging activities): Amounts reclassified into net income 836 (317 ) 519 836 (318 ) 518 FSIRS other comprehensive income 836 (317 ) 519 836 (318 ) 518 Foreign currency translation adjustments: Translation adjustments (510 ) — (510 ) — — — Foreign currency other comprehensive income (loss) (510 ) — (510 ) — — — Total other comprehensive income (loss) $ 1,468 $ (751 ) $ 717 $ 1,661 $ (631 ) $ 1,030 Nine Months Ended September 30, 2015 Nine Months Ended September 30, 2014 Before- Tax Tax Net-of- Tax Before- Tax Tax Net-of- Defined benefit pension plans: Amortization of prior service cost $ 1,001 $ (380 ) $ 621 $ 266 $ (101 ) $ 165 Amortization of net actuarial (gain)/loss 25,786 (9,799 ) 15,987 17,742 (6,742 ) $ 11,000 Regulatory adjustment (23,361 ) 8,877 (14,484 ) (15,533 ) 5,903 (9,630 ) Pension plans other comprehensive income (loss) 3,426 (1,302 ) 2,124 2,475 (940 ) 1,535 FSIRS (designated hedging activities): Amounts reclassifed into net income 2,508 (952 ) 1,556 2,509 (954 ) 1,555 FSIRS other comprehensive income 2,508 (952 ) 1,556 2,509 (954 ) 1,555 Foreign currency translation adjustments: Translation adjustments (1,573 ) — (1,573 ) — — — Foreign currency other comprehensive income (loss) (1,573 ) — (1,573 ) — — — Total other comprehensive income (loss) $ 4,361 $ (2,254 ) $ 2,107 $ 4,984 $ (1,894 ) $ 3,090 Twelve Months Ended September 30, 2015 Twelve Months Ended September 30, 2014 Before- Tax Tax Net-of- Tax Before- Tax Tax Net-of- Defined benefit pension plans: Net actuarial gain (loss) $ (173,646 ) $ 65,985 $ (107,661 ) $ 100,345 $ (38,131 ) $ 62,214 Amortization of prior service cost 1,090 (414 ) 676 355 (134 ) 221 Amortization of net actuarial (gain)/loss 31,700 (12,046 ) 19,654 26,285 (9,988 ) 16,297 Prior service cost (6,661 ) 2,531 (4,130 ) — — — Regulatory adjustment 132,480 (50,343 ) 82,137 (116,412 ) 44,236 (72,176 ) Pension plans other comprehensive income (loss) (15,037 ) 5,713 (9,324 ) 10,573 (4,017 ) 6,556 FSIRS (designated hedging activities): Amounts reclassified into net income 3,344 (1,270 ) 2,074 3,345 (1,271 ) 2,074 FSIRS other comprehensive income (loss) 3,344 (1,270 ) 2,074 3,345 (1,271 ) 2,074 Foreign currency translation adjustments: Translation adjustments (2,232 ) — (2,232 ) — — — Foreign currency other comprehensive income (loss) (2,232 ) — (2,232 ) — — — Total other comprehensive income (loss) $ (13,925 ) $ 4,443 $ (9,482 ) $ 13,918 $ (5,288 ) $ 8,630 (1) Tax amounts are calculated using a 38% rate. The Company has elected to indefinitely reinvest the earnings of Centuri’s Canadian subsidiaries in Canada, thus preventing deferred taxes on such earnings. As a result of this assertion, the Company is not recognizing any tax effect or presenting a tax expense or benefit for the currency translation adjustment amount reported in Other Comprehensive Income, as repatriation of earnings is not anticipated. Approximately $2.1 million of realized losses (net of tax) related to the FSIRS, reported in Accumulated other comprehensive income (“AOCI”) at September 30, 2015, will be reclassified into interest expense within the next 12 months, as the related interest payments on long-term debt occur. The following table represents a rollforward of AOCI, presented on the Company’s Condensed Consolidated Balance Sheets: AOCI—Rollforward (Thousands of dollars) Defined Benefit Plans FSIRS Foreign Currency Items Before-Tax Tax After-Tax Before-Tax Tax After-Tax Before-Tax Tax After-Tax AOCI Beginning Balance AOCI December 31, 2014 $ (57,211 ) $ 21,740 $ (35,471 ) $ (22,688 ) $ 8,621 $ (14,067 ) $ (637 ) $ — $ (637 ) $ (50,175 ) Translation adjustments — — — — — — (1,573 ) — (1,573 ) (1,573 ) Other comprehensive income before reclassifications — — — — — — (1,573 ) — (1,573 ) (1,573 ) FSIRS amounts reclassified from AOCI (1) — — — 2,508 (952 ) 1,556 — — — 1,556 Amortization of prior service cost (2) 1,001 (380 ) 621 — — — — — — 621 Amortization of net actuarial loss (2) 25,786 (9,799 ) 15,987 — — — — — — 15,987 Regulatory adjustment (3) (23,361 ) 8,877 (14,484 ) — — — — — — (14,484 ) Net current period other comprehensive income (loss) 3,426 (1,302 ) 2,124 2,508 (952 ) 1,556 (1,573 ) — (1,573 ) 2,107 Less: Translation adjustment attributable to redeemable noncontrolling interest — — — — — — (55 ) — (55 ) (55 ) Net current period other comprehensive income (loss) attributable to Southwest Gas Corporation 3,426 (1,302 ) 2,124 2,508 (952 ) 1,556 (1,518 ) — (1,518 ) 2,162 Ending Balance AOCI September 30, 2015 $ (53,785 ) $ 20,438 $ (33,347 ) $ (20,180 ) $ 7,669 $ (12,511 ) $ (2,155 ) $ — $ (2,155 ) $ (48,013 ) (1) The FSIRS reclassification amounts are included in the Net interest deductions line item on the Condensed Consolidated Statements of Income. (2) These AOCI components are included in the computation of net periodic benefit cost (see Note 2 – Components of Net Periodic Benefit Cost (3) The regulatory adjustment represents the portion of the activity above that is expected to be recovered through rates in the future (the related regulatory asset is included in the Deferred charges and other assets line item on the Condensed Consolidated Balance Sheets). The following table represents amounts (before income tax impacts) associated with defined benefit plans, and included in AOCI (in the table above), that have not yet been recognized in net periodic benefit cost: Amounts Recognized in AOCI (Before Tax) (Thousands of dollars) September December Net actuarial (loss) gain $ (413,345 ) $ (439,131 ) Prior service cost (7,372 ) (8,373 ) Less: amount recognized in regulatory assets 366,932 390,293 Recognized in AOCI $ (53,785 ) $ (57,211 ) |
Acquisition of Construction Ser
Acquisition of Construction Services Businesses | 9 Months Ended |
Sep. 30, 2015 | |
Business Combinations [Abstract] | |
Acquisition of Construction Services Businesses | Note 8 – Acquisition of Construction Services Businesses In October 2014, the Company, through its subsidiaries, completed the acquisition of three privately held, affiliated construction businesses. See the Company’s 2014 Form 10-K and the first quarter 2015 Form 10-Q for additional information about this acquisition. While refinements were made to the estimated fair values of assets acquired and liabilities assumed during the first quarter of 2015, no subsequent adjustments were made to acquisition-date values. The final purchase accounting has been completed. |
Construction Services Redeemabl
Construction Services Redeemable Noncontrolling Interest | 9 Months Ended |
Sep. 30, 2015 | |
Noncontrolling Interest [Abstract] | |
Construction Services Redeemable Noncontrolling Interest | Note 9 – Construction Services Redeemable Noncontrolling Interest At the close of the acquisition discussed above, previous owners of the acquired companies retained an approximate 10% equity interest in the Canadian-specific businesses. The agreement, associated with that approximate 10% equity interest, provided special dividend rights which entitled the sellers, as holders, to dividends equal to 3.4% of dividends paid at the level of Centuri, and subject to certain conditions, such interests could become exchangeable for a 3.4% equity interest in Centuri. In consideration of the underlying exchange rights of the original agreement, earnings attribution by Centuri to the previous owners has also occurred in an amount equivalent to 3.4% of Centuri earnings since October 2014. During the third quarter of 2015, the sellers formally exercised their exchange rights under the terms of that original agreement. No new rights were conveyed to the noncontrolling parties as a result of the exchange and no new consideration was involved. The ability of the sellers to redeem their holdings for cash at specified dates remains intact. The previous owners may exit their investment retained by requiring the purchase of a portion of their interest commencing July 2017 and in incremental amounts each anniversary date thereafter. The shares subject to the election cumulate (if earlier elections are not made) such that 100% of their interest retained is subject to the election beginning in July 2022. Due to the continued ability of the noncontrolling parties to redeem their interest for cash, their interest continues to be presented on the Company’s Condensed Consolidated Balance Sheet at September 30, 2015 as a Redeemable noncontrolling interest, a category of mezzanine equity (temporary equity), in accordance with SEC guidance. However, that interest, previously associated with the Canadian businesses, is now formally an interest in Centuri. Significant changes in the value of the redeemable noncontrolling interest are recognized as they occur, and the carrying value is adjusted as necessary at each reporting date. Guidance by the SEC indicates that downward adjustments in the value of redeemable noncontrolling interests are only permitted to the extent that upward adjustments in value were previously recognized. A floor for the noncontrolling interest was originally set at the acquisition date (in October 2014). However, U.S. GAAP generally views changes in ownership interest, where the parent retains its controlling interest, as an equity transaction, whereby the carrying amount of the noncontrolling interest is adjusted to reflect the change in ownership interest in the subsidiary. In connection with the exchange rights being exercised during the third quarter, an updated valuation was conducted. A significant decrease in the value of the redeemable noncontrolling interest was recognized, due in part to the exchange option no longer being subject to probability estimates. In light of the U.S. GAAP requirement to adjust the carrying amount, a new floor has been set for the redeemable noncontrolling interest at the exchange date, with a corresponding adjustment (approximately $6 million) made to additional paid in capital of the Company. Future adjustments to the redemption value are not permitted below the new floor. The following depicts impacts to the balance of the redeemable noncontrolling interest between the indicated periods. Redeemable (Thousands of dollars): Balance, December 31, 2014 $ 20,042 Net income attributable to redeemable noncontrolling interest 454 Foreign currency exchange translation adjustment (55 ) Adjustment to redemption value (6,738 ) Balance, September 30, 2015 $ 13,703 The redemption value of the redeemable noncontrolling interest utilizes a market approach to determine a construction services enterprise value. Potential guideline publicly traded companies have been identified by using a selection criteria, including actively traded equities, their financial solvency, and other factors. Once the guideline companies are determined, enterprise value is calculated using a weighted approach of projected earnings before interest expense and taxes (“EBIT”) and earnings before interest expense, taxes, and depreciation and amortization expense (“EBITDA”). After an estimated fair value is determined, it is multiplied by 3.4%. A discount is then applied due to limitations of the nonpublic noncontrolling interest being valued. Prior to the exchange rights being exercised in the third quarter of 2015, a Monte Carlo simulation methodology was used to assign a value to the redeemable noncontrolling interest. Each quarter, market changes in the guideline companies are considered and the weighted approach to projected EBIT and EBITDA, in relation to the guideline companies, is re-evaluated to determine if value changes are necessary at each quarterly reporting date. |
Nature of Operations and Basi16
Nature of Operations and Basis of Presentation (Policies) | 9 Months Ended |
Sep. 30, 2015 | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
Nature of Operations | Nature of Operations. |
Basis of Presentation | Basis of Presentation. Centuri, through its subsidiaries, holds a 50% interest in W.S. Nicholls Western Construction LTD. (“Western”), a Canadian construction services company that is a variable interest entity. Centuri determined that it is not the primary beneficiary of the entity due to a shared-power structure; therefore, Centuri does not consolidate the entity and has recorded its investment, and results related thereto, using the equity method. The Company’s investment in Western is not significant in relation to its total assets included in the Condensed Consolidated Balance Sheets. |
Prepaids and Other Current Assets | Prepaids and other current assets. |
Cash and Cash Equivalents | Cash and Cash Equivalents. Significant non-cash investing and financing activities for the natural gas operations segment included the following: Upon contract expiration, customer advances of approximately $2.8 million and $7 million, during the first nine months of 2015 and 2014, respectively, were applied as contributions toward utility construction activity and represent non-cash investing activity. |
Goodwill | Goodwill. Therefore, goodwill assigned to Brigadier is expected to be deductible for tax purposes, resulting in an after-tax value of $4.9 million. All other goodwill associated with the acquisition is not deductible for tax purposes. (In thousands of dollars) Natural Gas Construction Consolidated December 31, 2014 $ 10,095 $ 133,065 $ 143,160 Acquisition date adjustment — 1,380 1,380 Foreign currency translation adjustment — (14,656 ) (14,656 ) September 30, 2015 $ 10,095 $ 119,789 $ 129,884 |
Intercompany Transactions | Intercompany Transactions Note 3—Segment Information September 30, December 31, Centuri accounts receivable for services provided to Southwest $ 15,972 $ 9,169 The accounts receivable balance, revenues, and associated profits are included in the condensed consolidated financial statements of the Company and were not eliminated during consolidation in accordance with accounting treatment for rate-regulated entities. |
Other Property and Investments | Other Property and Investments. September 30, December 31, Centuri property and equipment $ 419 $ 405 Centuri accumulated provision for depreciation and amortization (209 ) (187 ) Net cash surrender value of COLI policies 97 99 Other property 12 10 Total $ 319 $ 327 |
Other Income (Deductions) | Other Income (Deductions). Three Months Ended Nine Months Ended Twelve Months Ended September 30 September 30 September 30 2015 2014 2015 2014 2015 2014 Change in COLI policies $ (3,900 ) $ (300 ) $ (2,600 ) $ 2,900 $ (200 ) $ 7,200 Interest income 624 772 1,375 1,881 2,096 1,920 Foreign transaction gain (loss) (302 ) — (874 ) — (1,052 ) — Miscellaneous income and (expense) (82 ) (32 ) 873 134 122 (94 ) Total other income (deductions) $ (3,660 ) $ 440 $ (1,226 ) $ 4,915 $ 966 $ 9,026 Included in the table above is the change in cash surrender values of company-owned life insurance (“COLI”) policies (including net death benefits recognized). These life insurance policies on members of management and other key employees are used by Southwest to indemnify itself against the loss of talent, expertise, and knowledge, as well as to provide indirect funding for certain nonqualified benefit plans. Current tax regulations provide for tax-free treatment of life insurance (death benefit) proceeds. Therefore, changes in the cash surrender values of COLI policies, as they progress towards the ultimate death benefits, are also recorded without tax consequences. |
Recently Issued Accounting Standards Updates | Recently Issued Accounting Standards Updates. In August 2014, the FASB issued the update “Disclosure of Uncertainties about an Entity’s Ability to Continue as a Going Concern,” which requires management to assess a company’s ability to continue as a going concern and to provide related footnote disclosures in certain circumstances. Under the update, disclosures are required when conditions give rise to substantial doubt about a company’s ability to continue as a going concern within one year from the financial statement issuance date. The update is effective for the annual period ending after December 15, 2016, and all annual and interim periods thereafter. This update is not expected to have a material impact on the Company’s disclosures. In April 2015, the FASB issued the update “Interest—Imputation of Interest (Subtopic 835-30) Simplifying the Presentation of Debt Issuance Costs.” To simplify presentation of debt issuance costs, the amendments in this update require 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 the amendments in this update. Retrospective application of the update is required. The amendments in this update are effective for financial statements issued for fiscal years beginning after December 15, 2015, and interim periods within fiscal years beginning after December 15, 2016. Early adoption of the amendments in this update is permitted for financial statements that have not been previously issued. This update is not expected to have a material impact on the Company’s consolidated financial statements and disclosures. |
Nature of Operations and Basi17
Nature of Operations and Basis of Presentation (Tables) | 9 Months Ended |
Sep. 30, 2015 | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
Schedule of Goodwill | (In thousands of dollars) Natural Gas Construction Consolidated December 31, 2014 $ 10,095 $ 133,065 $ 143,160 Acquisition date adjustment — 1,380 1,380 Foreign currency translation adjustment — (14,656 ) (14,656 ) September 30, 2015 $ 10,095 $ 119,789 $ 129,884 |
Intercompany Transactions | Centuri’s accounts receivable for these services are presented in the table below (thousands of dollars): September 30, December 31, Centuri accounts receivable for services provided to Southwest $ 15,972 $ 9,169 |
Schedule of Other Property and Investments | Other Property and Investments. September 30, December 31, Centuri property and equipment $ 419 $ 405 Centuri accumulated provision for depreciation and amortization (209 ) (187 ) Net cash surrender value of COLI policies 97 99 Other property 12 10 Total $ 319 $ 327 |
Other Income (Deductions) | The following table provides the composition of significant items included in Other income (deductions) in the condensed consolidated statements of income (thousands of dollars): Three Months Ended Nine Months Ended Twelve Months Ended September 30 September 30 September 30 2015 2014 2015 2014 2015 2014 Change in COLI policies $ (3,900 ) $ (300 ) $ (2,600 ) $ 2,900 $ (200 ) $ 7,200 Interest income 624 772 1,375 1,881 2,096 1,920 Foreign transaction gain (loss) (302 ) — (874 ) — (1,052 ) — Miscellaneous income and (expense) (82 ) (32 ) 873 134 122 (94 ) Total other income (deductions) $ (3,660 ) $ 440 $ (1,226 ) $ 4,915 $ 966 $ 9,026 |
Components of Net Periodic Be18
Components of Net Periodic Benefit Cost (Tables) | 9 Months Ended |
Sep. 30, 2015 | |
Text Block [Abstract] | |
Schedule of Components of Net Periodic Benefit Costs | As a result, net periodic benefit costs become components of various accounts, primarily operations and maintenance expense, net utility plant, and deferred charges and other assets. Qualified Retirement Plan Period Ended September 30, Three Months Nine Months Twelve Months 2015 2014 2015 2014 2015 2014 (Thousands of dollars) Service cost $ 6,281 $ 5,340 $ 18,842 $ 16,020 $ 24,182 $ 21,784 Interest cost 11,057 10,860 33,172 32,581 44,031 41,983 Expected return on plan assets (14,452 ) (13,336 ) (43,356 ) (40,007 ) (56,691 ) (52,467 ) Amortization of net actuarial loss 8,186 5,718 24,557 17,154 30,276 25,219 Net periodic benefit cost $ 11,072 $ 8,582 $ 33,215 $ 25,748 $ 41,798 $ 36,519 SERP Period Ended September 30, Three Months Nine Months Twelve Months 2015 2014 2015 2014 2015 2014 (Thousands of dollars) Service cost $ 80 $ 73 $ 240 $ 219 $ 313 $ 312 Interest cost 424 436 1,271 1,308 1,708 1,692 Amortization of net actuarial loss 323 196 970 588 1,165 830 Net periodic benefit cost $ 827 $ 705 $ 2,481 $ 2,115 $ 3,186 $ 2,834 PBOP Period Ended September 30, Three Months Nine Months Twelve Months 2015 2014 2015 2014 2015 2014 (Thousands of dollars) Service cost $ 410 $ 275 $ 1,231 $ 826 $ 1,506 $ 1,131 Interest cost 750 707 2,249 2,122 2,956 2,743 Expected return on plan assets (866 ) (816 ) (2,598 ) (2,448 ) (3,414 ) (3,154 ) Amortization of prior service costs 334 89 1,001 266 1,090 355 Amortization of net actuarial loss 86 — 259 — 259 236 Net periodic benefit cost $ 714 $ 255 $ 2,142 $ 766 $ 2,397 $ 1,311 |
Segment Information (Tables)
Segment Information (Tables) | 9 Months Ended |
Sep. 30, 2015 | |
Segment Reporting [Abstract] | |
Schedule of Segment Reporting Information | The following tables present revenues from external customers, intersegment revenues, and segment net income (thousands of dollars): Natural Gas Construction Total Three months ended September 30, 2015 Revenues from external customers $ 219,420 $ 255,088 $ 474,508 Intersegment revenues — 30,888 30,888 Total $ 219,420 $ 285,976 $ 505,396 Segment net income (loss) $ (18,939 ) $ 14,205 $ (4,734 ) Three months ended September 30, 2014 Revenues from external customers $ 226,027 $ 183,290 $ 409,317 Intersegment revenues — 23,158 23,158 Total $ 226,027 $ 206,448 $ 432,475 Segment net income (loss) $ (11,452 ) $ 13,422 $ 1,970 Natural Gas Construction Total Nine months ended September 30, 2015 Revenues from external customers $ 1,059,178 $ 645,289 $ 1,704,467 Intersegment revenues — 73,753 73,753 Total $ 1,059,178 $ 719,042 $ 1,778,220 Segment net income $ 59,325 $ 12,873 $ 72,198 Nine months ended September 30, 2014 Revenues from external customers $ 983,999 $ 438,409 $ 1,422,408 Intersegment revenues — 71,616 71,616 Total $ 983,999 $ 510,025 $ 1,494,024 Segment net income $ 62,945 $ 19,435 $ 82,380 Natural Gas Construction Total Twelve months ended September 30, 2015 Revenues from external customers $ 1,457,266 $ 854,312 $ 2,311,578 Intersegment revenues — 94,325 94,325 Total $ 1,457,266 $ 948,637 $ 2,405,903 Segment net income $ 113,252 $ 17,692 $ 130,944 Twelve months ended September 30, 2014 Revenues from external customers $ 1,356,653 $ 577,384 $ 1,934,037 Intersegment revenues — 98,344 98,344 Total $ 1,356,653 $ 675,728 $ 2,032,381 Segment net income $ 117,797 $ 21,886 $ 139,683 |
Derivatives and Fair Value Me20
Derivatives and Fair Value Measurements (Tables) | 9 Months Ended |
Sep. 30, 2015 | |
Derivative Instruments and Hedging Activities Disclosure [Abstract] | |
Notional Amounts under Swaps Contracts | The differential is calculated based on the notional amounts under the contracts, which are detailed in the table below (thousands of dekatherms): September 30, December 31, Contract notional amounts 8,192 5,105 |
Amount of Gain or Losses Recognized in Income on Derivatives | The following table sets forth the gains and (losses) recognized on the Company’s Swaps (derivatives) for the three-, nine-, and twelve-month periods ended September 30, 2015 and 2014 and their location in the Condensed Consolidated Statements of Income: Gains (losses) recognized in income for derivatives not designated as hedging instruments: (Thousands of dollars) Location of Gain or (Loss) Three Months Ended Nine Months Ended Twelve Months Ended September 30 September 30 September 30 Instrument 2015 2014 2015 2014 2015 2014 Swaps Net cost of gas sold $ (3,282 ) $ (2,277 ) $ (4,689 ) $ 3,630 $ (10,682 ) $ 7,552 Swaps Net cost of gas sold 3,282 * 2,277 * 4,689 * (3,630 )* 10,682 * (7,552 )* Total $ — $ — $ — $ — $ — $ — * Represents the impact of regulatory deferral accounting treatment under U.S. GAAP for rate-regulated entities. |
Fair Values of Swaps in Condensed Consolidated Balance Sheets | The following table sets forth the fair values of the Company’s Swaps and their location in the Condensed Consolidated Balance Sheets (thousands of dollars): Fair values of derivatives not designated as hedging instruments: September 30, 2015 Asset Derivatives Liability Derivatives Net Total Instrument Balance Sheet Location Swaps Other current liabilities $ — $ (3,425 ) $ (3,425 ) Swaps Other deferred credits — (1,462 ) (1,462 ) Total $ — $ (4,887 ) $ (4,887 ) December 31, 2014 Asset Derivatives Liability Derivatives Net Total Instrument Balance Sheet Location Swaps Other current liabilities $ — $ (5,062 ) $ (5,062 ) Swaps Other deferred credits — (363 ) (363 ) Total $ — $ (5,425 ) $ (5,425 ) |
Paid to and Received from Counterparties for Settlements of Matured Swaps | The following table shows the amounts Southwest paid to and received from counterparties for settlements of matured Swaps. Three Months Ended Nine Months Ended Twelve Months Ended (Thousands of dollars) September 30, 2015 September 30, 2015 September 30, 2015 Paid to counterparties $ 568 $ 5,228 $ 5,971 Received from counterparties $ — $ — $ 120 |
Regulatory Assets/Liabilities Offsetting Derivatives at Fair Value in Condensed Consolidated Balance Sheets | The following table details the regulatory assets/(liabilities) offsetting the derivatives at fair value in the Condensed Consolidated Balance Sheets (thousands of dollars). September 30, 2015 Instrument Balance Sheet Location Net Total Swaps Prepaids and other current assets $ 3,425 Swaps Deferred charges and other assets 1,462 December 31, 2014 Instrument Balance Sheet Location Net Total Swaps Prepaids and other current assets $ 5,062 Swaps Deferred charges and other assets 363 |
Significant Other Observable Inputs | The following table sets forth by level within the three-level fair value hierarchy that ranks the inputs used to measure fair value by their reliability, the Company’s financial assets and liabilities that were accounted for at fair value: Level 2—Significant other observable inputs (Thousands of dollars) September 30, December 31, Liabilities at fair value: Other current liabilities—Swaps $ (3,425 ) $ (5,062 ) Other deferred credits—Swaps (1,462 ) (363 ) Net Assets (Liabilities) $ (4,887 ) $ (5,425 ) |
Long-Term Debt (Tables)
Long-Term Debt (Tables) | 9 Months Ended |
Sep. 30, 2015 | |
Debt Disclosure [Abstract] | |
Schedule of Carrying Amounts and Estimated Fair Values of Long-Term Debt | Since Centuri’s debt is not publicly traded, fair values for the secured revolving credit and term loan facility and other debt obligations were based on a conventional discounted cash flow methodology and utilized current market pricing yield curves, across Centuri’s debt maturity spectrum, of other industrial bonds with an assumed credit rating comparable to the Company’s. September 30, 2015 December 31, 2014 Carrying Market Carrying Market (Thousands of dollars) Debentures: Notes, 4.45%, due 2020 $ 125,000 $ 132,769 $ 125,000 $ 133,403 Notes, 6.1%, due 2041 125,000 147,451 125,000 157,290 Notes, 3.875%, due 2022 250,000 263,023 250,000 262,030 Notes, 4.875%, due 2043 250,000 266,370 250,000 280,903 8% Series, due 2026 75,000 99,380 75,000 102,296 Medium-term notes, 7.59% series, due 2017 25,000 26,662 25,000 27,573 Medium-term notes, 7.78% series, due 2022 25,000 30,621 25,000 31,144 Medium-term notes, 7.92% series, due 2027 25,000 32,726 25,000 33,695 Medium-term notes, 6.76% series, due 2027 7,500 8,917 7,500 9,156 Unamortized discount (4,957 ) (5,223 ) 902,543 902,277 Revolving credit facility and commercial paper 97,000 97,000 150,000 150,000 Industrial development revenue bonds: Variable-rate bonds: Tax-exempt Series A, due 2028 50,000 50,000 50,000 50,000 2003 Series A, due 2038 50,000 50,000 50,000 50,000 2008 Series A, due 2038 50,000 50,000 50,000 50,000 2009 Series A, due 2039 50,000 50,000 50,000 50,000 Fixed-rate bonds: 5.25% 2003 Series D, due 2038 — — 20,000 20,277 5.00% 2004 Series B, due 2033 — — 31,200 31,223 4.85% 2005 Series A, due 2035 100,000 100,415 100,000 100,071 4.75% 2006 Series A, due 2036 24,855 25,089 24,855 25,399 Unamortized discount (1,539 ) (1,943 ) 323,316 374,112 Centuri secured revolving credit and term loan facility 208,787 209,213 199,267 200,341 Centuri other debt obligations 28,583 28,868 31,128 31,127 1,560,229 1,656,784 Less: current maturities (19,865 ) (19,192 ) Long-term debt, less current maturities $ 1,540,364 $ 1,637,592 |
Equity, Other Comprehensive I22
Equity, Other Comprehensive Income, and Accumulated Other Comprehensive Income (Tables) | 9 Months Ended |
Sep. 30, 2015 | |
Equity [Abstract] | |
Detailed Activities of Equity and Redeemable Noncontrolling Interest | The table below provides details of activity in equity and the redeemable noncontrolling interest during the nine months ended September 30, 2015. Southwest Gas Corporation Equity Additional Paid-in Capital Accumulated Comprehensive Income (Loss) Redeemable Interest (Temporary Common Stock Retained Non-controlling (In thousands except per share amounts) Shares Amount Total DECEMBER 31, 2014 46,523 $ 48,153 $ 851,381 $ (50,175 ) $ 639,164 $ (2,257 ) $ 1,486,266 $ 20,042 Common stock issuances 852 852 37,467 38,319 Net income (loss) 72,198 80 72,278 454 Redemption value adjustments 5,777 961 6,738 (6,738 ) Foreign currency exchange translation adj. (1,518 ) (1,518 ) (55 ) Other comprehensive income (loss): Net actuarial gain (loss) arising during period, less amortization of unamortized benefit plan cost, net of tax 2,124 2,124 Amounts reclassified to net income, net of tax (FSIRS) 1,556 1,556 Dividends declared Common: $1.215 per share (57,831 ) (57,831 ) SEPTEMBER 30, 2015 47,375 $ 49,005 $ 894,625 $ (48,013 ) $ 654,492 $ (2,177 ) $ 1,547,932 $ 13,703 |
Related Tax Effects Allocated to Each Component of Other Comprehensive Income (Loss) | Related Tax Effects Allocated to Each Component of Other Comprehensive Income (Loss) (Thousands of dollars) Three Months Ended September 30, 2015 Three Months Ended September 30, 2014 Before- Tax Net-of- Before- Tax Net-of- Defined benefit pension plans: Amortization of prior service cost $ 334 $ (127 ) $ 207 $ 89 $ (34 ) $ 55 Amortization of net actuarial (gain)/loss 8,595 (3,266 ) 5,329 5,914 (2,247 ) 3,667 Regulatory adjustment (7,787 ) 2,959 (4,828 ) (5,178 ) 1,968 (3,210 ) Pension plans other comprehensive income (loss) 1,142 (434 ) 708 825 (313 ) 512 FSIRS (designated hedging activities): Amounts reclassified into net income 836 (317 ) 519 836 (318 ) 518 FSIRS other comprehensive income 836 (317 ) 519 836 (318 ) 518 Foreign currency translation adjustments: Translation adjustments (510 ) — (510 ) — — — Foreign currency other comprehensive income (loss) (510 ) — (510 ) — — — Total other comprehensive income (loss) $ 1,468 $ (751 ) $ 717 $ 1,661 $ (631 ) $ 1,030 Nine Months Ended September 30, 2015 Nine Months Ended September 30, 2014 Before- Tax Tax Net-of- Tax Before- Tax Tax Net-of- Defined benefit pension plans: Amortization of prior service cost $ 1,001 $ (380 ) $ 621 $ 266 $ (101 ) $ 165 Amortization of net actuarial (gain)/loss 25,786 (9,799 ) 15,987 17,742 (6,742 ) $ 11,000 Regulatory adjustment (23,361 ) 8,877 (14,484 ) (15,533 ) 5,903 (9,630 ) Pension plans other comprehensive income (loss) 3,426 (1,302 ) 2,124 2,475 (940 ) 1,535 FSIRS (designated hedging activities): Amounts reclassifed into net income 2,508 (952 ) 1,556 2,509 (954 ) 1,555 FSIRS other comprehensive income 2,508 (952 ) 1,556 2,509 (954 ) 1,555 Foreign currency translation adjustments: Translation adjustments (1,573 ) — (1,573 ) — — — Foreign currency other comprehensive income (loss) (1,573 ) — (1,573 ) — — — Total other comprehensive income (loss) $ 4,361 $ (2,254 ) $ 2,107 $ 4,984 $ (1,894 ) $ 3,090 Twelve Months Ended September 30, 2015 Twelve Months Ended September 30, 2014 Before- Tax Tax Net-of- Tax Before- Tax Tax Net-of- Defined benefit pension plans: Net actuarial gain (loss) $ (173,646 ) $ 65,985 $ (107,661 ) $ 100,345 $ (38,131 ) $ 62,214 Amortization of prior service cost 1,090 (414 ) 676 355 (134 ) 221 Amortization of net actuarial (gain)/loss 31,700 (12,046 ) 19,654 26,285 (9,988 ) 16,297 Prior service cost (6,661 ) 2,531 (4,130 ) — — — Regulatory adjustment 132,480 (50,343 ) 82,137 (116,412 ) 44,236 (72,176 ) Pension plans other comprehensive income (loss) (15,037 ) 5,713 (9,324 ) 10,573 (4,017 ) 6,556 FSIRS (designated hedging activities): Amounts reclassified into net income 3,344 (1,270 ) 2,074 3,345 (1,271 ) 2,074 FSIRS other comprehensive income (loss) 3,344 (1,270 ) 2,074 3,345 (1,271 ) 2,074 Foreign currency translation adjustments: Translation adjustments (2,232 ) — (2,232 ) — — — Foreign currency other comprehensive income (loss) (2,232 ) — (2,232 ) — — — Total other comprehensive income (loss) $ (13,925 ) $ 4,443 $ (9,482 ) $ 13,918 $ (5,288 ) $ 8,630 (1) Tax amounts are calculated using a 38% rate. The Company has elected to indefinitely reinvest the earnings of Centuri’s Canadian subsidiaries in Canada, thus preventing deferred taxes on such earnings. As a result of this assertion, the Company is not recognizing any tax effect or presenting a tax expense or benefit for the currency translation adjustment amount reported in Other Comprehensive Income, as repatriation of earnings is not anticipated. |
Rollforward of Accumulated Other Comprehensive Income | The following table represents a rollforward of AOCI, presented on the Company’s Condensed Consolidated Balance Sheets: AOCI—Rollforward (Thousands of dollars) Defined Benefit Plans FSIRS Foreign Currency Items Before-Tax Tax After-Tax Before-Tax Tax After-Tax Before-Tax Tax After-Tax AOCI Beginning Balance AOCI December 31, 2014 $ (57,211 ) $ 21,740 $ (35,471 ) $ (22,688 ) $ 8,621 $ (14,067 ) $ (637 ) $ — $ (637 ) $ (50,175 ) Translation adjustments — — — — — — (1,573 ) — (1,573 ) (1,573 ) Other comprehensive income before reclassifications — — — — — — (1,573 ) — (1,573 ) (1,573 ) FSIRS amounts reclassified from AOCI (1) — — — 2,508 (952 ) 1,556 — — — 1,556 Amortization of prior service cost (2) 1,001 (380 ) 621 — — — — — — 621 Amortization of net actuarial loss (2) 25,786 (9,799 ) 15,987 — — — — — — 15,987 Regulatory adjustment (3) (23,361 ) 8,877 (14,484 ) — — — — — — (14,484 ) Net current period other comprehensive income (loss) 3,426 (1,302 ) 2,124 2,508 (952 ) 1,556 (1,573 ) — (1,573 ) 2,107 Less: Translation adjustment attributable to redeemable noncontrolling interest — — — — — — (55 ) — (55 ) (55 ) Net current period other comprehensive income (loss) attributable to Southwest Gas Corporation 3,426 (1,302 ) 2,124 2,508 (952 ) 1,556 (1,518 ) — (1,518 ) 2,162 Ending Balance AOCI September 30, 2015 $ (53,785 ) $ 20,438 $ (33,347 ) $ (20,180 ) $ 7,669 $ (12,511 ) $ (2,155 ) $ — $ (2,155 ) $ (48,013 ) (1) The FSIRS reclassification amounts are included in the Net interest deductions line item on the Condensed Consolidated Statements of Income. (2) These AOCI components are included in the computation of net periodic benefit cost (see Note 2 – Components of Net Periodic Benefit Cost (3) The regulatory adjustment represents the portion of the activity above that is expected to be recovered through rates in the future (the related regulatory asset is included in the Deferred charges and other assets line item on the Condensed Consolidated Balance Sheets). |
Amount Recognized Before Income Tax Associated with Defined Benefit Plans in Accumulated Other Comprehensive Income | The following table represents amounts (before income tax impacts) associated with defined benefit plans, and included in AOCI (in the table above), that have not yet been recognized in net periodic benefit cost: Amounts Recognized in AOCI (Before Tax) (Thousands of dollars) September December Net actuarial (loss) gain $ (413,345 ) $ (439,131 ) Prior service cost (7,372 ) (8,373 ) Less: amount recognized in regulatory assets 366,932 390,293 Recognized in AOCI $ (53,785 ) $ (57,211 ) |
Construction Services Redeema23
Construction Services Redeemable Noncontrolling Interest (Tables) | 9 Months Ended |
Sep. 30, 2015 | |
Noncontrolling Interest [Abstract] | |
Summary of Redeemable Noncontrolling Interest | The following depicts impacts to the balance of the redeemable noncontrolling interest between the indicated periods. Redeemable (Thousands of dollars): Balance, December 31, 2014 $ 20,042 Net income attributable to redeemable noncontrolling interest 454 Foreign currency exchange translation adjustment (55 ) Adjustment to redemption value (6,738 ) Balance, September 30, 2015 $ 13,703 |
Nature of Operations and Basi24
Nature of Operations and Basis of Presentation - Additional Information (Detail) | 6 Months Ended | 9 Months Ended | ||
Sep. 30, 2015USD ($) | Sep. 30, 2015USD ($)Segment | Sep. 30, 2014USD ($) | Dec. 31, 2014USD ($) | |
Significant Accounting Policies [Line Items] | ||||
Number of segments | Segment | 2 | |||
Non-cash construction advances - non-cash investing item | $ 2,800,000 | $ 7,000,000 | ||
Goodwill impairment charges | 0 | |||
Acquisition date adjustments to goodwill | $ 0 | 1,380,000 | ||
Brigadier Pipelines Inc. [Member] | ||||
Significant Accounting Policies [Line Items] | ||||
Goodwill assigned for deductible tax purpose | 4,900,000 | $ 4,900,000 | ||
Centuri Construction Group Inc [Member] | ||||
Significant Accounting Policies [Line Items] | ||||
Ownership percentage in subsidiary | 96.60% | |||
Centuri Construction Group Inc [Member] | W.S. Nicholls Western Construction LTD. [Member] | ||||
Significant Accounting Policies [Line Items] | ||||
Subsidiaries holding interest percentage | 50.00% | |||
Pooled funds and mutual funds [Member] | Level 2 - Significant other observable inputs [Member] | ||||
Significant Accounting Policies [Line Items] | ||||
Money market fund investments | 250,000 | $ 250,000 | $ 250,000 | |
Gas Pipe Materials and Supplies [Member] | ||||
Significant Accounting Policies [Line Items] | ||||
Gas pipe materials and supplies | $ 25,000,000 | $ 25,000,000 | $ 23,000,000 |
Nature of Operations and Basi25
Nature of Operations and Basis of Presentation - Schedule of Goodwill (Detail) - USD ($) | 6 Months Ended | 9 Months Ended |
Sep. 30, 2015 | Sep. 30, 2015 | |
Goodwill [Line Items] | ||
Goodwill, Beginning balance | $ 143,160,000 | |
Acquisition date adjustment | $ 0 | 1,380,000 |
Foreign currency translation adjustment | (14,656,000) | |
Goodwill, Ending balance | 129,884,000 | 129,884,000 |
Natural Gas Operations [Member] | ||
Goodwill [Line Items] | ||
Goodwill, Beginning balance | 10,095,000 | |
Acquisition date adjustment | 0 | |
Foreign currency translation adjustment | 0 | |
Goodwill, Ending balance | 10,095,000 | 10,095,000 |
Construction Services [Member] | ||
Goodwill [Line Items] | ||
Goodwill, Beginning balance | 133,065,000 | |
Acquisition date adjustment | 1,380,000 | |
Foreign currency translation adjustment | (14,656,000) | |
Goodwill, Ending balance | $ 119,789,000 | $ 119,789,000 |
Nature of Operations and Basi26
Nature of Operations and Basis of Presentation - Intercompany Transactions (Detail) - USD ($) $ in Thousands | Sep. 30, 2015 | Dec. 31, 2014 |
Centuri Construction Group Inc [Member] | ||
Accounts, Notes, Loans and Financing Receivable [Line Items] | ||
Centuri accounts receivable for services provided to Southwest | $ 15,972 | $ 9,169 |
Nature of Operations and Basi27
Nature of Operations and Basis of Presentation - Schedule of Other Property and Investments (Detail) - USD ($) $ in Thousands | Sep. 30, 2015 | Dec. 31, 2014 |
Investment [Line Items] | ||
Net cash surrender value of COLI policies | $ 97,000 | $ 99,000 |
Other property | 12,000 | 10,000 |
Total | 319,243 | 326,743 |
Centuri Construction Group Inc [Member] | ||
Investment [Line Items] | ||
Centuri property and equipment | 419,000 | 405,000 |
Centuri accumulated provision for depreciation and amortization | $ (209,000) | $ (187,000) |
Nature of Operations and Basi28
Nature of Operations and Basis of Presentation - Other Income (Deductions) (Detail) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | 12 Months Ended | |||
Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | |
Other Income and Expenses [Abstract] | ||||||
Change in COLI policies | $ (3,900) | $ (300) | $ (2,600) | $ 2,900 | $ (200) | $ 7,200 |
Interest income | 624 | 772 | 1,375 | 1,881 | 2,096 | 1,920 |
Foreign transaction gain (loss) | (302) | 0 | (874) | 0 | (1,052) | 0 |
Miscellaneous income and (expense) | (82) | (32) | 873 | 134 | 122 | (94) |
Total other income (deductions) | $ (3,660) | $ 440 | $ (1,226) | $ 4,915 | $ 966 | $ 9,026 |
Components of Net Periodic Be29
Components of Net Periodic Benefit Cost - Schedule of Components of Net Periodic Benefit Costs (Detail) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | 12 Months Ended | |||
Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | |
Qualified Retirement Plan [Member] | ||||||
Defined Benefit Plan Disclosure [Line Items] | ||||||
Service cost | $ 6,281 | $ 5,340 | $ 18,842 | $ 16,020 | $ 24,182 | $ 21,784 |
Interest cost | 11,057 | 10,860 | 33,172 | 32,581 | 44,031 | 41,983 |
Expected return on plan assets | (14,452) | (13,336) | (43,356) | (40,007) | (56,691) | (52,467) |
Amortization of net actuarial loss | 8,186 | 5,718 | 24,557 | 17,154 | 30,276 | 25,219 |
Net periodic benefit cost | 11,072 | 8,582 | 33,215 | 25,748 | 41,798 | 36,519 |
SERP [Member] | ||||||
Defined Benefit Plan Disclosure [Line Items] | ||||||
Service cost | 80 | 73 | 240 | 219 | 313 | 312 |
Interest cost | 424 | 436 | 1,271 | 1,308 | 1,708 | 1,692 |
Amortization of net actuarial loss | 323 | 196 | 970 | 588 | 1,165 | 830 |
Net periodic benefit cost | 827 | 705 | 2,481 | 2,115 | 3,186 | 2,834 |
PBOP [Member] | ||||||
Defined Benefit Plan Disclosure [Line Items] | ||||||
Service cost | 410 | 275 | 1,231 | 826 | 1,506 | 1,131 |
Interest cost | 750 | 707 | 2,249 | 2,122 | 2,956 | 2,743 |
Expected return on plan assets | (866) | (816) | (2,598) | (2,448) | (3,414) | (3,154) |
Amortization of prior service costs | 334 | 89 | 1,001 | 266 | 1,090 | 355 |
Amortization of net actuarial loss | 86 | 0 | 259 | 0 | 259 | 236 |
Net periodic benefit cost | $ 714 | $ 255 | $ 2,142 | $ 766 | $ 2,397 | $ 1,311 |
Segment Information - Schedule
Segment Information - Schedule of Segment Reporting Information (Detail) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | 12 Months Ended | |||
Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | |
Segment Reporting Information [Line Items] | ||||||
Total operating revenues | $ 505,396 | $ 432,475 | $ 1,778,220 | $ 1,494,024 | $ 2,405,903 | $ 2,032,381 |
Segment net income (loss) | (4,734) | 1,970 | 72,198 | 82,380 | 130,944 | 139,683 |
Revenues from external customers [Member] | ||||||
Segment Reporting Information [Line Items] | ||||||
Revenues | 474,508 | 409,317 | 1,704,467 | 1,422,408 | 2,311,578 | 1,934,037 |
Intersegment revenues [Member] | ||||||
Segment Reporting Information [Line Items] | ||||||
Revenues | 30,888 | 23,158 | 73,753 | 71,616 | 94,325 | 98,344 |
Natural Gas Operations [Member] | ||||||
Segment Reporting Information [Line Items] | ||||||
Total operating revenues | 219,420 | 226,027 | 1,059,178 | 983,999 | 1,457,266 | 1,356,653 |
Segment net income (loss) | (18,939) | (11,452) | 59,325 | 62,945 | 113,252 | 117,797 |
Natural Gas Operations [Member] | Revenues from external customers [Member] | ||||||
Segment Reporting Information [Line Items] | ||||||
Revenues | 219,420 | 226,027 | 1,059,178 | 983,999 | 1,457,266 | 1,356,653 |
Natural Gas Operations [Member] | Intersegment revenues [Member] | ||||||
Segment Reporting Information [Line Items] | ||||||
Revenues | 0 | 0 | 0 | 0 | 0 | 0 |
Construction Services [Member] | ||||||
Segment Reporting Information [Line Items] | ||||||
Total operating revenues | 285,976 | 206,448 | 719,042 | 510,025 | 948,637 | 675,728 |
Segment net income (loss) | 14,205 | 13,422 | 12,873 | 19,435 | 17,692 | 21,886 |
Construction Services [Member] | Revenues from external customers [Member] | ||||||
Segment Reporting Information [Line Items] | ||||||
Revenues | 255,088 | 183,290 | 645,289 | 438,409 | 854,312 | 577,384 |
Construction Services [Member] | Intersegment revenues [Member] | ||||||
Segment Reporting Information [Line Items] | ||||||
Revenues | $ 30,888 | $ 23,158 | $ 73,753 | $ 71,616 | $ 94,325 | $ 98,344 |
Derivatives and Fair Value Me31
Derivatives and Fair Value Measurements - Additional Information (Detail) - USD ($) | 3 Months Ended | 9 Months Ended | 12 Months Ended | |||
Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | |
Derivative [Line Items] | ||||||
Gains (losses) recognized in income or other comprehensive income for derivative designated cash flow hedges | $ 519,000 | $ 518,000 | $ 1,556,000 | $ 1,555,000 | $ 2,074,000 | $ 2,074,000 |
Derivative instrument loss at settlement amortization period | 10 years | |||||
Cash flow hedging [Member] | ||||||
Derivative [Line Items] | ||||||
Gains (losses) recognized in income or other comprehensive income for derivative designated cash flow hedges | $ 0 | |||||
Minimum [Member] | ||||||
Derivative [Line Items] | ||||||
Maturities of natural gas swaps | Oct. 31, 2015 | |||||
Maximum [Member] | ||||||
Derivative [Line Items] | ||||||
Maturities of natural gas swaps | Mar. 31, 2017 | |||||
Arizona [Member] | ||||||
Derivative [Line Items] | ||||||
Natural gas portfolios, maximum % rate | 25.00% | |||||
California [Member] | ||||||
Derivative [Line Items] | ||||||
Natural gas portfolios, maximum % rate | 25.00% |
Derivatives and Fair Value Me32
Derivatives and Fair Value Measurements - Notional Amounts under Swaps Contracts (Detail) - MMBTU | Sep. 30, 2015 | Dec. 31, 2014 |
Offsetting [Abstract] | ||
Contract notional amounts | 8,192,000 | 5,105,000 |
Derivatives and Fair Value Me33
Derivatives and Fair Value Measurements - Amount of Gain or Losses Recognized in Income on Derivatives (Detail) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | 12 Months Ended | |||
Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | |
Derivative Instruments, Gain (Loss) [Line Items] | ||||||
Amount of gain or (loss) recognized in income on derivative | $ 0 | $ 0 | $ 0 | $ 0 | $ 0 | $ 0 |
Cash flow hedging [Member] | Net cost of gas sold [Member] | ||||||
Derivative Instruments, Gain (Loss) [Line Items] | ||||||
Amount of gain or (loss) recognized in income on derivative | (3,282) | (2,277) | (4,689) | 3,630 | (10,682) | 7,552 |
Regulatory deferral accounting treatment [Member] | Cash flow hedging [Member] | Net cost of gas sold [Member] | ||||||
Derivative Instruments, Gain (Loss) [Line Items] | ||||||
Amount of gain or (loss) recognized in income on derivative | $ 3,282 | $ 2,277 | $ 4,689 | $ (3,630) | $ 10,682 | $ (7,552) |
Derivatives and Fair Value Me34
Derivatives and Fair Value Measurements - Fair Values of Swaps in Condensed Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands | Sep. 30, 2015 | Dec. 31, 2014 |
Derivatives, Fair Value [Line Items] | ||
Asset derivatives not designated as hedging instruments | $ 0 | $ 0 |
Liability derivatives not designated as hedging instruments | (4,887) | (5,425) |
Net total not designated as hedging instruments | (4,887) | (5,425) |
Swaps [Member] | Other current liabilities [Member] | ||
Derivatives, Fair Value [Line Items] | ||
Asset derivatives not designated as hedging instruments | 0 | 0 |
Liability derivatives not designated as hedging instruments | (3,425) | (5,062) |
Net total not designated as hedging instruments | (3,425) | (5,062) |
Swaps [Member] | Other deferred credits [Member] | ||
Derivatives, Fair Value [Line Items] | ||
Asset derivatives not designated as hedging instruments | 0 | 0 |
Liability derivatives not designated as hedging instruments | (1,462) | (363) |
Net total not designated as hedging instruments | $ (1,462) | $ (363) |
Derivatives and Fair Value Me35
Derivatives and Fair Value Measurements - Paid to and Received from Counterparties for Settlements of Matured Swaps (Detail) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | 12 Months Ended |
Sep. 30, 2015 | Sep. 30, 2015 | Sep. 30, 2015 | |
Derivative Instruments And Hedging Activities Disclosure [Abstract] | |||
Paid to counterparties | $ 568 | $ 5,228 | $ 5,971 |
Received from counterparties | $ 0 | $ 0 | $ 120 |
Derivatives and Fair Value Me36
Derivatives and Fair Value Measurements - Regulatory Assets/Liabilities Offsetting Derivatives at Fair Value in Condensed Consolidated Balance Sheets (Detail) - Swaps [Member] - USD ($) $ in Thousands | Sep. 30, 2015 | Dec. 31, 2014 |
Prepaids and other current assets [Member] | ||
Derivatives, Fair Value [Line Items] | ||
Net Total | $ 3,425 | $ 5,062 |
Deferred charges and other assets [Member] | ||
Derivatives, Fair Value [Line Items] | ||
Net Total | $ 1,462 | $ 363 |
Derivatives and Fair Value Me37
Derivatives and Fair Value Measurements - Significant Other Observable Inputs (Detail) - Level 2 - Significant other observable inputs [Member] - USD ($) $ in Thousands | Sep. 30, 2015 | Dec. 31, 2014 |
Derivatives, Fair Value [Line Items] | ||
Net Assets (Liabilities) | $ (4,887) | $ (5,425) |
Swaps [Member] | Other current liabilities [Member] | ||
Derivatives, Fair Value [Line Items] | ||
Derivative Liabilities | (3,425) | (5,062) |
Swaps [Member] | Other deferred credits [Member] | ||
Derivatives, Fair Value [Line Items] | ||
Derivative Liabilities | $ (1,462) | $ (363) |
Common Stock - Additional Infor
Common Stock - Additional Information (Detail) - USD ($) | Mar. 10, 2015 | Sep. 30, 2015 | Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 |
Net proceeds to Company | $ 35,419,000 | $ 419,000 | $ 35,405,000 | $ 608,000 | ||
Common stock issued through Stock Incentive Plan, Restricted Stock/Unit Plan, and Management Incentive Plan | 207,000 | |||||
BNY Mellon Capital Markets, LLC [Member] | ||||||
Common stock sold through agent | 272,716 | 645,225 | ||||
Common stock weighted average price | $ 54.12 | |||||
Net proceeds to Company | $ 14,610,439 | $ 35,167,584 | ||||
Agent commissions | 147,579 | 355,228 | ||||
Common stock available for sale under the program | $ 64,477,188 | $ 64,477,188 | $ 64,477,188 | |||
Maximum [Member] | ||||||
Value of common stock | $ 100,000,000 |
Long-Term Debt - Schedule of Ca
Long-Term Debt - Schedule of Carrying Amounts and Estimated Fair Values of Long-Term Debt (Detail) - USD ($) $ in Thousands | Sep. 30, 2015 | Dec. 31, 2014 |
Long-term Debt, Current and Noncurrent Abstract | ||
Less: current maturities | $ (19,865) | $ (19,192) |
Long-term debt, less current maturities | 1,540,364 | 1,637,592 |
Carrying Amount [Member] | ||
Debt Instrument [Line Items] | ||
Total long-term debt | 1,560,229 | 1,656,784 |
Long-term Debt, Current and Noncurrent Abstract | ||
Less: current maturities | (19,865) | (19,192) |
Long-term debt, less current maturities | 1,540,364 | 1,637,592 |
Total long-term debt | 1,560,229 | 1,656,784 |
Carrying Amount [Member] | IDRBs [Member] | ||
Debt Instrument [Line Items] | ||
Unsecured debt | 323,316 | 374,112 |
Carrying Amount [Member] | Centuri secured revolving credit and term loan facility [Member] | ||
Debt Instrument [Line Items] | ||
Centuri secured revolving credit and term loan facility | 208,787 | 199,267 |
Carrying Amount [Member] | Centuri other debt obligations [Member] | ||
Debt Instrument [Line Items] | ||
Centuri other debt obligations | 28,583 | 31,128 |
Carrying Amount [Member] | Debentures [Member] | ||
Debt Instrument [Line Items] | ||
Unamortized discount | (4,957) | (5,223) |
Notes payable | 902,543 | 902,277 |
Carrying Amount [Member] | Debentures [Member] | Notes, 4.45%, due 2020 [Member] | ||
Debt Instrument [Line Items] | ||
Notes payable | 125,000 | 125,000 |
Carrying Amount [Member] | Debentures [Member] | Notes, 6.1%, due 2041 [Member] | ||
Debt Instrument [Line Items] | ||
Notes payable | 125,000 | 125,000 |
Carrying Amount [Member] | Debentures [Member] | Notes, 3.875%, due 2022 [Member] | ||
Debt Instrument [Line Items] | ||
Notes payable | 250,000 | 250,000 |
Carrying Amount [Member] | Debentures [Member] | Notes, 4.875%, due 2043 [Member] | ||
Debt Instrument [Line Items] | ||
Notes payable | 250,000 | 250,000 |
Carrying Amount [Member] | Debentures [Member] | 8% Series, due 2026 [Member] | ||
Debt Instrument [Line Items] | ||
Notes payable | 75,000 | 75,000 |
Carrying Amount [Member] | Debentures [Member] | Medium-term notes, 7.59% series, due 2017 [Member] | ||
Debt Instrument [Line Items] | ||
Notes payable | 25,000 | 25,000 |
Carrying Amount [Member] | Debentures [Member] | Medium-term notes, 7.78% series, due 2022 [Member] | ||
Debt Instrument [Line Items] | ||
Notes payable | 25,000 | 25,000 |
Carrying Amount [Member] | Debentures [Member] | Medium-term notes, 7.92% series, due 2027 [Member] | ||
Debt Instrument [Line Items] | ||
Notes payable | 25,000 | 25,000 |
Carrying Amount [Member] | Debentures [Member] | Medium-term notes, 6.76% series, due 2027 [Member] | ||
Debt Instrument [Line Items] | ||
Notes payable | 7,500 | 7,500 |
Carrying Amount [Member] | Debentures [Member] | Revolving credit facility and commercial paper [Member] | ||
Debt Instrument [Line Items] | ||
Line of credit facility | 97,000 | 150,000 |
Carrying Amount [Member] | Variable-rate bonds [Member] | Tax-exempt Series A, due 2028 [Member] | ||
Debt Instrument [Line Items] | ||
Unsecured debt | 50,000 | 50,000 |
Carrying Amount [Member] | Variable-rate bonds [Member] | 2003 Series A, due 2038 [Member] | ||
Debt Instrument [Line Items] | ||
Unsecured debt | 50,000 | 50,000 |
Carrying Amount [Member] | Variable-rate bonds [Member] | 2008 Series A, due 2038 [Member] | ||
Debt Instrument [Line Items] | ||
Unsecured debt | 50,000 | 50,000 |
Carrying Amount [Member] | Variable-rate bonds [Member] | 2009 Series A, due 2039 [Member] | ||
Debt Instrument [Line Items] | ||
Unsecured debt | 50,000 | 50,000 |
Carrying Amount [Member] | Fixed-rate bonds [Member] | ||
Debt Instrument [Line Items] | ||
Unamortized discount | (1,539) | (1,943) |
Carrying Amount [Member] | Fixed-rate bonds [Member] | 5.25% 2003 Series D, due 2038 [Member] | ||
Debt Instrument [Line Items] | ||
Unsecured debt | 20,000 | |
Carrying Amount [Member] | Fixed-rate bonds [Member] | 5.00% 2004 Series B, due 2033 [Member] | ||
Debt Instrument [Line Items] | ||
Unsecured debt | 31,200 | |
Carrying Amount [Member] | Fixed-rate bonds [Member] | 4.85% 2005 Series A, due 2035 [Member] | ||
Debt Instrument [Line Items] | ||
Unsecured debt | 100,000 | 100,000 |
Carrying Amount [Member] | Fixed-rate bonds [Member] | 4.75% 2006 Series A, due 2036 [Member] | ||
Debt Instrument [Line Items] | ||
Unsecured debt | 24,855 | 24,855 |
Market Value [Member] | Centuri secured revolving credit and term loan facility [Member] | ||
Debt Instrument [Line Items] | ||
Centuri secured revolving credit and term loan facility | 209,213 | 200,341 |
Market Value [Member] | Centuri other debt obligations [Member] | ||
Debt Instrument [Line Items] | ||
Centuri other debt obligations | 28,868 | 31,127 |
Market Value [Member] | Debentures [Member] | Notes, 4.45%, due 2020 [Member] | ||
Debt Instrument [Line Items] | ||
Notes payable, fair value disclosure | 132,769 | 133,403 |
Market Value [Member] | Debentures [Member] | Notes, 6.1%, due 2041 [Member] | ||
Debt Instrument [Line Items] | ||
Notes payable, fair value disclosure | 147,451 | 157,290 |
Market Value [Member] | Debentures [Member] | Notes, 3.875%, due 2022 [Member] | ||
Debt Instrument [Line Items] | ||
Notes payable, fair value disclosure | 263,023 | 262,030 |
Market Value [Member] | Debentures [Member] | Notes, 4.875%, due 2043 [Member] | ||
Debt Instrument [Line Items] | ||
Notes payable, fair value disclosure | 266,370 | 280,903 |
Market Value [Member] | Debentures [Member] | 8% Series, due 2026 [Member] | ||
Debt Instrument [Line Items] | ||
Notes payable, fair value disclosure | 99,380 | 102,296 |
Market Value [Member] | Debentures [Member] | Medium-term notes, 7.59% series, due 2017 [Member] | ||
Debt Instrument [Line Items] | ||
Notes payable, fair value disclosure | 26,662 | 27,573 |
Market Value [Member] | Debentures [Member] | Medium-term notes, 7.78% series, due 2022 [Member] | ||
Debt Instrument [Line Items] | ||
Notes payable, fair value disclosure | 30,621 | 31,144 |
Market Value [Member] | Debentures [Member] | Medium-term notes, 7.92% series, due 2027 [Member] | ||
Debt Instrument [Line Items] | ||
Notes payable, fair value disclosure | 32,726 | 33,695 |
Market Value [Member] | Debentures [Member] | Medium-term notes, 6.76% series, due 2027 [Member] | ||
Debt Instrument [Line Items] | ||
Notes payable, fair value disclosure | 8,917 | 9,156 |
Market Value [Member] | Debentures [Member] | Revolving credit facility and commercial paper [Member] | ||
Debt Instrument [Line Items] | ||
Line of credit facility, fair value | 97,000 | 150,000 |
Market Value [Member] | Variable-rate bonds [Member] | Tax-exempt Series A, due 2028 [Member] | ||
Debt Instrument [Line Items] | ||
Line of credit facility, fair value | 50,000 | 50,000 |
Market Value [Member] | Variable-rate bonds [Member] | 2003 Series A, due 2038 [Member] | ||
Debt Instrument [Line Items] | ||
Line of credit facility, fair value | 50,000 | 50,000 |
Market Value [Member] | Variable-rate bonds [Member] | 2008 Series A, due 2038 [Member] | ||
Debt Instrument [Line Items] | ||
Line of credit facility, fair value | 50,000 | 50,000 |
Market Value [Member] | Variable-rate bonds [Member] | 2009 Series A, due 2039 [Member] | ||
Debt Instrument [Line Items] | ||
Line of credit facility, fair value | 50,000 | 50,000 |
Market Value [Member] | Fixed-rate bonds [Member] | 5.25% 2003 Series D, due 2038 [Member] | ||
Debt Instrument [Line Items] | ||
Line of credit facility, fair value | 0 | 20,277 |
Market Value [Member] | Fixed-rate bonds [Member] | 5.00% 2004 Series B, due 2033 [Member] | ||
Debt Instrument [Line Items] | ||
Line of credit facility, fair value | 0 | 31,223 |
Market Value [Member] | Fixed-rate bonds [Member] | 4.85% 2005 Series A, due 2035 [Member] | ||
Debt Instrument [Line Items] | ||
Line of credit facility, fair value | 100,415 | 100,071 |
Market Value [Member] | Fixed-rate bonds [Member] | 4.75% 2006 Series A, due 2036 [Member] | ||
Debt Instrument [Line Items] | ||
Line of credit facility, fair value | $ 25,089 | $ 25,399 |
Long-Term Debt - Schedule of 40
Long-Term Debt - Schedule of Carrying Amounts and Estimated Fair Values of Long-Term Debt (Parenthetical) (Detail) | 9 Months Ended | 12 Months Ended | |
Sep. 30, 2015 | Dec. 31, 2014 | May. 31, 2015 | |
5.25% 2003 Series D, due 2038 [Member] | |||
Debt Instrument [Line Items] | |||
Debt instrument interest rate | 5.25% | ||
Debt instrument due date | Dec. 1, 2038 | ||
5.00% 2004 Series B, due 2033 [Member] | |||
Debt Instrument [Line Items] | |||
Debt instrument interest rate | 5.00% | ||
Debt instrument due date | Dec. 1, 2033 | ||
Debentures [Member] | Notes, 4.45%, due 2020 [Member] | |||
Debt Instrument [Line Items] | |||
Debt instrument interest rate | 4.45% | 4.45% | |
Debt instrument due date | Dec. 1, 2020 | Dec. 1, 2020 | |
Debentures [Member] | Notes, 6.1%, due 2041 [Member] | |||
Debt Instrument [Line Items] | |||
Debt instrument interest rate | 6.10% | 6.10% | |
Debt instrument due date | Feb. 15, 2041 | Feb. 15, 2041 | |
Debentures [Member] | Notes, 3.875%, due 2022 [Member] | |||
Debt Instrument [Line Items] | |||
Debt instrument interest rate | 3.875% | 3.875% | |
Debt instrument due date | Apr. 1, 2022 | Apr. 1, 2022 | |
Debentures [Member] | Notes, 4.875%, due 2043 [Member] | |||
Debt Instrument [Line Items] | |||
Debt instrument interest rate | 4.875% | 4.875% | |
Debt instrument due date | Oct. 1, 2043 | Oct. 1, 2043 | |
Debentures [Member] | 8% Series, due 2026 [Member] | |||
Debt Instrument [Line Items] | |||
Debt instrument interest rate | 8.00% | 8.00% | |
Debt instrument due date | Aug. 1, 2026 | Aug. 1, 2026 | |
Debentures [Member] | Medium-term notes, 7.59% series, due 2017 [Member] | |||
Debt Instrument [Line Items] | |||
Debt instrument interest rate | 7.59% | 7.59% | |
Debt instrument due date | Jan. 17, 2017 | Jan. 17, 2017 | |
Debentures [Member] | Medium-term notes, 7.78% series, due 2022 [Member] | |||
Debt Instrument [Line Items] | |||
Debt instrument interest rate | 7.78% | 7.78% | |
Debt instrument due date | Feb. 3, 2022 | Feb. 3, 2022 | |
Debentures [Member] | Medium-term notes, 7.92% series, due 2027 [Member] | |||
Debt Instrument [Line Items] | |||
Debt instrument interest rate | 7.92% | 7.92% | |
Debt instrument due date | Jun. 4, 2027 | Jun. 4, 2027 | |
Debentures [Member] | Medium-term notes, 6.76% series, due 2027 [Member] | |||
Debt Instrument [Line Items] | |||
Debt instrument interest rate | 6.76% | 6.76% | |
Debt instrument due date | Sep. 24, 2027 | Sep. 24, 2027 | |
Variable-rate bonds [Member] | Tax-exempt Series A, due 2028 [Member] | |||
Debt Instrument [Line Items] | |||
Debt instrument due date | Dec. 1, 2028 | Dec. 1, 2028 | |
Variable-rate bonds [Member] | 2003 Series A, due 2038 [Member] | |||
Debt Instrument [Line Items] | |||
Debt instrument due date | Mar. 1, 2038 | Mar. 1, 2038 | |
Variable-rate bonds [Member] | 2008 Series A, due 2038 [Member] | |||
Debt Instrument [Line Items] | |||
Debt instrument due date | Mar. 1, 2038 | Mar. 1, 2038 | |
Variable-rate bonds [Member] | 2009 Series A, due 2039 [Member] | |||
Debt Instrument [Line Items] | |||
Debt instrument due date | Dec. 1, 2039 | Dec. 1, 2039 | |
Fixed-rate bonds [Member] | 5.25% 2003 Series D, due 2038 [Member] | |||
Debt Instrument [Line Items] | |||
Debt instrument interest rate | 5.25% | 5.25% | |
Debt instrument due date | Mar. 1, 2038 | Mar. 1, 2038 | |
Fixed-rate bonds [Member] | 5.00% 2004 Series B, due 2033 [Member] | |||
Debt Instrument [Line Items] | |||
Debt instrument interest rate | 5.00% | 5.00% | |
Debt instrument due date | Dec. 1, 2033 | Dec. 1, 2033 | |
Fixed-rate bonds [Member] | 4.85% 2005 Series A, due 2035 [Member] | |||
Debt Instrument [Line Items] | |||
Debt instrument interest rate | 4.85% | 4.85% | |
Debt instrument due date | Oct. 1, 2035 | Oct. 1, 2035 | |
Fixed-rate bonds [Member] | 4.75% 2006 Series A, due 2036 [Member] | |||
Debt Instrument [Line Items] | |||
Debt instrument interest rate | 4.75% | 4.75% | |
Debt instrument due date | Sep. 1, 2036 | Sep. 1, 2036 |
Long-Term Debt - Additional Inf
Long-Term Debt - Additional Information (Detail) - USD ($) | 1 Months Ended | 9 Months Ended | 12 Months Ended | |||
Sep. 30, 2015 | May. 31, 2015 | Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | |
Debt Instrument [Line Items] | ||||||
Redemption of long term debt | $ 143,325,000 | $ 21,528,000 | $ 260,952,000 | $ 28,272,000 | ||
Southwest Gas Credit Facility [Member] | ||||||
Debt Instrument [Line Items] | ||||||
Credit facility maximum borrowing capacity | $ 300,000,000 | 300,000,000 | 300,000,000 | |||
Line of credit designated as long term debt | 150,000,000 | 150,000,000 | 150,000,000 | |||
Line of credit designated for working capital purposes | 150,000,000 | $ 150,000,000 | 150,000,000 | |||
Credit facility expiration date | Mar. 1, 2020 | |||||
Borrowings outstanding under facility | 47,000,000 | $ 47,000,000 | 47,000,000 | |||
Southwest Gas Credit Facility [Member] | LIBOR [Member] | ||||||
Debt Instrument [Line Items] | ||||||
Applicable margin | 1.00% | |||||
Southwest Gas Credit Facility [Member] | Alternative base rate [Member] | ||||||
Debt Instrument [Line Items] | ||||||
Applicable margin | 0.00% | |||||
Southwest Gas Credit Facility [Member] | Before Amendment [Member] | ||||||
Debt Instrument [Line Items] | ||||||
Credit facility expiration date | Mar. 1, 2019 | |||||
Centuri Construction Group Inc [Member] | Secured Revolving Credit and Term Loan Facility [Member] | ||||||
Debt Instrument [Line Items] | ||||||
Credit facility maximum borrowing capacity | 300,000,000 | $ 300,000,000 | 300,000,000 | |||
Credit facility expiration date | Oct. 31, 2019 | |||||
Borrowings outstanding under facility | 209,000,000 | $ 209,000,000 | 209,000,000 | |||
Debt secured by assets | 557,000,000 | $ 557,000,000 | 557,000,000 | |||
5.00% 2004 Series B, due 2033 [Member] | ||||||
Debt Instrument [Line Items] | ||||||
Redemption of long term debt | $ 31,200,000 | |||||
Debt instrument interest rate | 5.00% | |||||
Debt instrument original due date | Dec. 1, 2033 | |||||
Commercial Paper Program [Member] | ||||||
Debt Instrument [Line Items] | ||||||
Borrowings outstanding under facility | 50,000,000 | $ 50,000,000 | $ 50,000,000 | |||
5.25% 2003 Series D, due 2038 [Member] | ||||||
Debt Instrument [Line Items] | ||||||
Redemption of long term debt | $ 20,000,000 | |||||
Debt instrument interest rate | 5.25% | 5.25% | 5.25% | |||
Debt instrument original due date | Dec. 1, 2038 |
Equity, Other Comprehensive I42
Equity, Other Comprehensive Income, and Accumulated Other Comprehensive Income - Detailed Activities of Equity and Redeemable Noncontrolling Interest (Detail) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | 12 Months Ended | |||
Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | |
Schedule Of Stockholders Equity [Line Items] | ||||||
Balance | $ 1,486,266 | |||||
Balance | $ 20,042 | |||||
Balance, shares | 46,523,184 | |||||
Common stock issuances | $ 38,319 | |||||
Net income (loss) | $ (4,734) | $ 1,970 | 72,198 | $ 82,380 | $ 130,944 | $ 139,683 |
Net income (loss) | 72,278 | |||||
Redemption value adjustments | 6,738 | |||||
Balance | 13,703 | 13,703 | 13,703 | |||
Foreign currency exchange translation adj. | (1,518) | |||||
Other comprehensive income (loss): | ||||||
Net actuarial gain (loss) arising during period, less amortization of unamortized benefit plan cost, net of tax | 708 | 512 | 2,124 | 1,535 | (9,324) | 6,556 |
Amounts reclassified into net income | 519 | $ 518 | 1,556 | $ 1,555 | 2,074 | $ 2,074 |
Dividends declared Common: $1.215 per share | (57,831) | |||||
Balance | $ 1,547,932 | $ 1,547,932 | $ 1,547,932 | |||
Balance, shares | 47,375,398 | 47,375,398 | 47,375,398 | |||
Common Stock [Member] | ||||||
Schedule Of Stockholders Equity [Line Items] | ||||||
Balance | $ 48,153 | |||||
Balance, shares | 46,523,000 | |||||
Common stock issuances | $ 852 | |||||
Common stock issuance, shares | 852,000 | |||||
Other comprehensive income (loss): | ||||||
Balance | $ 49,005 | $ 49,005 | $ 49,005 | |||
Balance, shares | 47,375,000 | 47,375,000 | 47,375,000 | |||
Additional Paid-in Capital [Member] | ||||||
Schedule Of Stockholders Equity [Line Items] | ||||||
Balance | $ 851,381 | |||||
Common stock issuances | 37,467 | |||||
Redemption value adjustments | 5,777 | |||||
Other comprehensive income (loss): | ||||||
Balance | $ 894,625 | 894,625 | $ 894,625 | |||
Accumulated Other Comprehensive Income (Loss) [Member] | ||||||
Schedule Of Stockholders Equity [Line Items] | ||||||
Balance | (50,175) | |||||
Foreign currency exchange translation adj. | (1,518) | |||||
Other comprehensive income (loss): | ||||||
Net actuarial gain (loss) arising during period, less amortization of unamortized benefit plan cost, net of tax | 2,124 | |||||
Amounts reclassified into net income | 1,556 | |||||
Balance | (48,013) | (48,013) | (48,013) | |||
Retained Earnings [Member] | ||||||
Schedule Of Stockholders Equity [Line Items] | ||||||
Balance | 639,164 | |||||
Net income (loss) | 72,198 | |||||
Redemption value adjustments | 961 | |||||
Other comprehensive income (loss): | ||||||
Dividends declared Common: $1.215 per share | (57,831) | |||||
Balance | 654,492 | 654,492 | 654,492 | |||
Non-controlling Interest [Member] | ||||||
Schedule Of Stockholders Equity [Line Items] | ||||||
Balance | (2,257) | |||||
Net income (loss) | 80 | |||||
Other comprehensive income (loss): | ||||||
Balance | (2,177) | (2,177) | (2,177) | |||
Redeemable Noncontrolling Interest (Temporary Equity) [Member] | ||||||
Schedule Of Stockholders Equity [Line Items] | ||||||
Balance | 20,042 | |||||
Net income (loss) | 454 | |||||
Redemption value adjustments | (6,738) | |||||
Foreign currency exchange translation adj. | (55) | |||||
Balance | $ 13,703 | $ 13,703 | $ 13,703 |
Equity, Other Comprehensive I43
Equity, Other Comprehensive Income, and Accumulated Other Comprehensive Income - Detailed Activities of Equity and Redeemable Noncontrolling Interest (Parenthetical) (Detail) - $ / shares | 3 Months Ended | 9 Months Ended | 12 Months Ended | |||
Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | |
Statement of Stockholders' Equity [Abstract] | ||||||
Dividends declared Common, per share | $ 0.405 | $ 0.365 | $ 1.215 | $ 1.095 | $ 1.580 | $ 1.425 |
Equity, Other Comprehensive I44
Equity, Other Comprehensive Income, and Accumulated Other Comprehensive Income - Related Tax Effects Allocated to Each Component of Other Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | 12 Months Ended | |||
Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | |
Equity [Abstract] | ||||||
Net actuarial gain/(loss), Before-Tax Amount | $ (173,646) | $ 100,345 | ||||
Amortization of prior service cost, Before-Tax Amount | $ 334 | $ 89 | $ 1,001 | $ 266 | 1,090 | 355 |
Amortization of net actuarial (gain)/loss, Before-Tax Amount | 8,595 | 5,914 | 25,786 | 17,742 | 31,700 | 26,285 |
Prior service cost, Before-Tax Amount | (6,661) | 0 | ||||
Regulatory adjustment, Before-Tax Amount | (7,787) | (5,178) | (23,361) | (15,533) | 132,480 | (116,412) |
Net current period other comprehensive income (loss), Defined Benefit Plans Before-Tax | 1,142 | 825 | 3,426 | 2,475 | (15,037) | 10,573 |
Amounts reclassified into net income, Before-Tax Amount | 836 | 836 | 2,508 | 2,509 | 3,344 | 3,345 |
FSIRS other comprehensive income (loss), Before-Tax Amount | 836 | 836 | 2,508 | 2,509 | 3,344 | 3,345 |
Translation adjustments, Before-Tax Amount | (510) | 0 | (1,573) | 0 | (2,232) | 0 |
Foreign currency other comprehensive income (loss), Before-Tax Amount | (510) | 0 | (1,573) | 0 | (2,232) | 0 |
Total other comprehensive income (loss), Before-Tax Amount | 1,468 | 1,661 | 4,361 | 4,984 | (13,925) | 13,918 |
Net actuarial gain/(loss), Tax (Expense) or Benefit | 65,985 | (38,131) | ||||
Amortization of prior service cost, Tax (Expense) or Benefit | (127) | (34) | (380) | (101) | (414) | (134) |
Amortization of net actuarial (gain)/loss, Tax (Expense) or Benefit | (3,266) | (2,247) | (9,799) | (6,742) | (12,046) | (9,988) |
Prior service cost, Tax (Expense) or Benefit | 2,531 | 0 | ||||
Regulatory adjustment, Tax (Expense) or Benefit | 2,959 | 1,968 | 8,877 | 5,903 | (50,343) | 44,236 |
Pension plans other comprehensive income (loss), Tax (Expense) or Benefit | (434) | (313) | (1,302) | (940) | 5,713 | (4,017) |
Amounts reclassified into net income, Tax (Expense) or Benefit | (317) | (318) | (952) | (954) | (1,270) | (1,271) |
FSIRS other comprehensive income (loss), Tax (Expense) or Benefit | (317) | (318) | (952) | (954) | (1,270) | (1,271) |
Translation adjustments, Tax (Expense) or Benefit | 0 | 0 | 0 | 0 | 0 | 0 |
Foreign currency other comprehensive income (loss), Tax (Expense) or Benefit | 0 | 0 | 0 | 0 | 0 | 0 |
Total other comprehensive income (loss), Tax (Expense) or Benefit | (751) | (631) | (2,254) | (1,894) | 4,443 | (5,288) |
Net actuarial gain/(loss), Net-of-Tax Amount | 0 | 0 | 0 | 0 | (107,661) | 62,214 |
Amortization of prior service cost, Net-of-Tax Amount | 207 | 55 | 621 | 165 | 676 | 221 |
Amortization of net actuarial (gain)/loss, Defined Benefit Plans After-Tax | 5,329 | 3,667 | 15,987 | 11,000 | 19,654 | 16,297 |
Prior service cost, Net-of-Tax Amount | 0 | 0 | 0 | 0 | (4,130) | 0 |
Regulatory adjustment, Net-of-Tax Amount | (4,828) | (3,210) | (14,484) | (9,630) | 82,137 | (72,176) |
Pension plans other comprehensive income (loss), Net-of-Tax Amount | 708 | 512 | 2,124 | 1,535 | (9,324) | 6,556 |
Amounts reclassified into net income | 519 | 518 | 1,556 | 1,555 | 2,074 | 2,074 |
FSIRS other comprehensive income (loss), Net-of-Tax Amount | 519 | 518 | 1,556 | 1,555 | 2,074 | 2,074 |
Translation adjustments, Net-of-Tax Amount | (510) | 0 | (1,573) | 0 | (2,232) | 0 |
Foreign currency other comprehensive income (loss), Net-of-Tax Amount | (510) | 0 | (1,573) | 0 | (2,232) | 0 |
Total other comprehensive income (loss), net of tax | $ 717 | $ 1,030 | $ 2,107 | $ 3,090 | $ (9,482) | $ 8,630 |
Equity, Other Comprehensive I45
Equity, Other Comprehensive Income, and Accumulated Other Comprehensive Income - Related Tax Effects Allocated to Each Component of Other Comprehensive Income (Loss) (Parenthetical) (Detail) | 9 Months Ended |
Sep. 30, 2015USD ($) | |
Equity [Abstract] | |
Other comprehensive income loss, effective income tax rate | 38.00% |
Tax expense or benefit for currency translation adjustment | $ 0 |
Equity, Other Comprehensive I46
Equity, Other Comprehensive Income, and Accumulated Other Comprehensive Income - Additional Information (Detail) $ in Millions | Sep. 30, 2015USD ($) |
Equity [Abstract] | |
Amount of FSIRS existing AOCI losses expected to reclassified income in next twelve months | $ 2.1 |
Equity, Other Comprehensive I47
Equity, Other Comprehensive Income, and Accumulated Other Comprehensive Income - Rollforward of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended | 12 Months Ended | |||
Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | Sep. 30, 2015 | Sep. 30, 2014 | |
Equity [Abstract] | ||||||
Beginning Balance AOCI December 31, 2014, Defined Benefit Plans Before-Tax | $ (57,211) | |||||
Translation adjustments, Defined Benefit Plans Before-Tax | 0 | |||||
Other comprehensive income before reclassifications, Defined Benefit Plans Before-Tax | 0 | |||||
Amortization of prior service cost, Defined Benefit Plans Before-Tax | $ 334 | $ 89 | 1,001 | $ 266 | $ 1,090 | $ 355 |
Amortization of net actuarial loss, Defined Benefit Plans Before-Tax | 8,595 | 5,914 | 25,786 | 17,742 | 31,700 | 26,285 |
Regulatory adjustment, Defined Benefit Plans Before-Tax | (7,787) | (5,178) | (23,361) | (15,533) | 132,480 | (116,412) |
Net current period other comprehensive income (loss), Defined Benefit Plans Before-Tax | 1,142 | 825 | 3,426 | 2,475 | (15,037) | 10,573 |
Less: Translation adjustment attributable to redeemable noncontrolling interest, Defined Benefit Plans Before-Tax | 0 | |||||
Net current period other comprehensive income (loss) attributable to Southwest Gas Corporation, Defined Benefit Plans Before-Tax | 3,426 | |||||
Ending Balance AOCI September 30, 2015, Defined Benefit Plans Before-Tax | (53,785) | (53,785) | (53,785) | |||
Beginning Balance AOCI December 31, 2014, Defined Benefit Plans Tax (Expense) Benefit | 21,740 | |||||
Translation adjustments, Defined Benefit Plans Tax (Expense) Benefit | 0 | |||||
Other comprehensive income before reclassifications, Defined Benefit Plans Tax (Expense) Benefit | 0 | |||||
Amortization of prior service cost, Defined Benefit Plans Tax (Expense) Benefit | (127) | (34) | (380) | (101) | (414) | (134) |
Amortization of net actuarial loss, Defined Benefit Plans Tax (Expense) Benefit | (3,266) | (2,247) | (9,799) | (6,742) | (12,046) | (9,988) |
Regulatory adjustment, Defined Benefit Plans Tax (Expense) Benefit | 2,959 | 1,968 | 8,877 | 5,903 | (50,343) | 44,236 |
Pension plans other comprehensive income (loss), Tax (Expense) or Benefit | (434) | (313) | (1,302) | (940) | 5,713 | (4,017) |
Less: Translation adjustment attributable to redeemable noncontrolling interest, Defined Benefit Plans Tax (Expense) Benefit | 0 | |||||
Net current period other comprehensive income (loss) attributable to Southwest Gas Corporation, Defined Benefit Plans Tax (Expense) Benefit | (1,302) | |||||
Ending Balance AOCI September 30, 2015, Defined Benefit Plans Tax (Expense) Benefit | 20,438 | 20,438 | 20,438 | |||
Beginning Balance AOCI December 31, 2014, Defined Benefit Plans After-Tax | (35,471) | |||||
Translation adjustments, Defined Benefit Plans After-Tax | 0 | |||||
Other comprehensive income before reclassifications, Defined Benefit Plans After-Tax | 0 | |||||
Amortization of prior service cost, Defined Benefit Plans After-Tax | 207 | 55 | 621 | 165 | 676 | 221 |
Amortization of net actuarial (gain)/loss, Defined Benefit Plans After-Tax | 5,329 | 3,667 | 15,987 | 11,000 | 19,654 | 16,297 |
Regulatory adjustment, Defined Benefit Plans After-Tax | (14,484) | |||||
Net defined benefit pension plans | 708 | 512 | 2,124 | 1,535 | (9,324) | 6,556 |
Less: Translation adjustment attributable to redeemable noncontrolling interest, Defined Benefit Plans After-Tax | 0 | |||||
Net current period other comprehensive income (loss) attributable to Southwest Gas Corporation, Defined Benefit Plans After-Tax | 2,124 | |||||
Ending Balance AOCI September 30, 2015, Defined Benefit Plans After-Tax | (33,347) | (33,347) | (33,347) | |||
Beginning Balance AOCI December 31, 2014, FSIRS - Before-Tax | (22,688) | |||||
Translation adjustments, FSIRS - Before-Tax | 0 | |||||
Other comprehensive income before reclassifications, FSIRS - Before-Tax | 0 | |||||
FSIRS amounts reclassified from AOCI, FSIRS - Before-Tax | 836 | 836 | 2,508 | 2,509 | 3,344 | 3,345 |
Net current period other comprehensive income (loss), FSIRS - Before-Tax | 836 | 836 | 2,508 | 2,509 | 3,344 | 3,345 |
Less: Translation adjustment attributable to redeemable noncontrolling interest, FSIRS - Before-Tax | 0 | |||||
Net current period other comprehensive income (loss) attributable to Southwest Gas Corporation, FSIRS - Before-Tax | 2,508 | |||||
Ending Balance AOCI September 30, 2015, FSIRS - Before-Tax | (20,180) | (20,180) | (20,180) | |||
Beginning Balance AOCI December 31, 2014, FSIRS - Tax (Expense) Benefit | 8,621 | |||||
Translation adjustments, FSIRS - Tax (Expense) Benefit | 0 | |||||
Other comprehensive income before reclassifications, FSIRS - Tax (Expense) Benefit | 0 | |||||
FSIRS amounts reclassified from AOCI, FSIRS - Tax (Expense) Benefit | (317) | (318) | (952) | (954) | (1,270) | (1,271) |
Net current period other comprehensive income (loss), FSIRS - Tax (Expense) Benefit | (317) | (318) | (952) | (954) | (1,270) | (1,271) |
Less: Translation adjustment attributable to redeemable noncontrolling interest, FSIRS - Tax (Expense) Benefit | 0 | |||||
Net current period other comprehensive income (loss) attributable to Southwest Gas Corporation, FSIRS - Tax (Expense) Benefit | (952) | |||||
Ending Balance AOCI September 30, 2015, FSIRS - Tax (Expense) Benefit | 7,669 | 7,669 | 7,669 | |||
Beginning Balance AOCI December 31, 2014, FSIRS - After-Tax | (14,067) | |||||
Translation adjustments, FSIRS - After-Tax | 0 | |||||
Other comprehensive income before reclassifications, FSIRS - After-Tax | 0 | |||||
FSIRS amounts reclassified from AOCI, FSIRS - After-Tax | 519 | 518 | 1,556 | 1,555 | 2,074 | 2,074 |
Net forward-starting interest rate swaps | 519 | 518 | 1,556 | 1,555 | 2,074 | 2,074 |
Less: Translation adjustment attributable to redeemable noncontrolling interest, FSIRS - After-Tax | 0 | |||||
Net current period other comprehensive income (loss) attributable to Southwest Gas Corporation, FSIRS - After-Tax | 1,556 | |||||
Ending Balance AOCI September 30, 2015, FSIRS - After-Tax | (12,511) | (12,511) | (12,511) | |||
Beginning Balance AOCI December 31, 2014, Foreign Currency Items Before-Tax | (637) | |||||
Translation adjustments, Foreign Currency Items Before-Tax | (510) | 0 | (1,573) | 0 | (2,232) | 0 |
Other comprehensive income before reclassifications, Foreign Currency Items Before-Tax | (510) | 0 | (1,573) | 0 | (2,232) | 0 |
FSIRS amounts reclassified from AOCI, Foreign Currency Items Before-Tax | 0 | |||||
Amortization of prior service cost, Foreign Currency Items Before-Tax | 0 | |||||
Amortization of net actuarial loss, Foreign Currency Items Before-Tax | 0 | |||||
Regulatory adjustment, Foreign Currency Items Before-Tax | 0 | |||||
Net current period other comprehensive income (loss), Foreign Currency Items Before-Tax | (1,573) | |||||
Less: Translation adjustment attributable to redeemable noncontrolling interest, Foreign Currency Items Before-Tax | (55) | |||||
Net current period other comprehensive income (loss) attributable to Southwest Gas Corporation, Foreign Currency Items Before-Tax | (1,518) | |||||
Ending Balance AOCI September 30, 2015, Foreign Currency Items Before-Tax | (2,155) | (2,155) | (2,155) | |||
Beginning Balance AOCI December 31, 2014, Foreign Currency items - Tax (Expense) Benefit | 0 | |||||
Translation adjustments, Foreign Currency items - Tax (Expense) Benefit | 0 | 0 | 0 | 0 | 0 | 0 |
Other comprehensive income before reclassifications, Foreign Currency items - Tax (Expense) Benefit | 0 | |||||
FSIRS amounts reclassified from AOCI, Foreign Currency items - Tax (Expense) Benefit | 0 | |||||
Amortization of prior service cost ,Foreign Currency items - Tax (Expense) Benefit | 0 | |||||
Amortization of net actuarial loss, Foreign Currency items - Tax (Expense) Benefit | 0 | |||||
Regulatory adjustment, Foreign Currency items - Tax (Expense) Benefit | 0 | |||||
Net current period other comprehensive income (loss), Foreign Currency items - Tax (Expense) Benefit | 0 | |||||
Less: Translation adjustment attributable to redeemable noncontrolling interest, Foreign Currency items - Tax (Expense) Benefit | 0 | |||||
Net current period other comprehensive income (loss) attributable to Southwest Gas Corporation, Foreign Currency items - Tax (Expense) Benefit | 0 | 0 | 0 | 0 | 0 | 0 |
Ending Balance AOCI September 30, 2015, Foreign Currency items - Tax (Expense) Benefit | 0 | 0 | 0 | |||
Beginning Balance AOCI December 31, 2014, Foreign Currency items - After-Tax | (637) | |||||
Translation adjustments, Foreign Currency items - After-Tax | (510) | 0 | (1,573) | 0 | (2,232) | 0 |
Other comprehensive income before reclassifications, Foreign Currency items - After-Tax | (510) | 0 | (1,573) | 0 | (2,232) | 0 |
FSIRS amounts reclassified from AOCI, Foreign Currency items - After-Tax | 0 | |||||
Amortization of prior service cost, Foreign Currency items - After-Tax | 0 | |||||
Amortization of net actuarial loss, Foreign Currency items - After-Tax | 0 | |||||
Regulatory adjustment, Foreign Currency items - After-Tax | 0 | |||||
Net current period other comprehensive income (loss), Foreign Currency items - After-Tax | (1,573) | |||||
Less: Translation adjustment attributable to redeemable noncontrolling interest, Foreign Currency items - After-Tax | (55) | |||||
Net current period other comprehensive income (loss) attributable to Southwest Gas Corporation, Foreign Currency Items - After-Tax | (1,518) | |||||
Ending Balance AOCI September 30, 2015, Foreign Currency items - After-Tax | (2,155) | (2,155) | (2,155) | |||
Beginning Balance AOCI December 31, 2014, AOCI | (50,175) | |||||
Translation adjustments, AOCI | (1,573) | (1,573) | (1,573) | |||
Other comprehensive income before reclassifications, AOCI | (1,573) | |||||
Amounts reclassified into net income | 519 | 518 | 1,556 | 1,555 | 2,074 | 2,074 |
Amortization of prior service cost, AOCI | 207 | 55 | 621 | 165 | 676 | 221 |
Amortization of net actuarial loss | 5,329 | 3,667 | 15,987 | 11,000 | 19,654 | 16,297 |
Regulatory adjustment, AOCI | (14,484) | |||||
Total other comprehensive income (loss), net of tax | 717 | $ 1,030 | 2,107 | $ 3,090 | (9,482) | $ 8,630 |
Less: Translation adjustment attributable to redeemable noncontrolling interest, AOCI | (55) | (55) | (55) | |||
Net current period other comprehensive income (loss) attributable to Southwest Gas Corporation, AOCI | 2,162 | 2,162 | 2,162 | |||
Ending Balance AOCI September 30, 2015, AOCI | $ (48,013) | $ (48,013) | $ (48,013) |
Equity, Other Comprehensive I48
Equity, Other Comprehensive Income, and Accumulated Other Comprehensive Income - Amount Recognized Before Income Tax Associated with Defined Benefit Plans in Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands | Sep. 30, 2015 | Dec. 31, 2014 |
Accumulated Other Comprehensive Income (Loss) [Line Items] | ||
Recognized in AOCI | $ 53,785 | $ 57,211 |
Defined Benefit Plans [Member] | ||
Accumulated Other Comprehensive Income (Loss) [Line Items] | ||
Net actuarial (loss) gain | (413,345) | (439,131) |
Prior service cost | (7,372) | (8,373) |
Less: amount recognized in regulatory assets | 366,932 | 390,293 |
Recognized in AOCI | $ (53,785) | $ (57,211) |
Acquisition of Construction S49
Acquisition of Construction Services Businesses - Additional Information (Detail) - USD ($) | 6 Months Ended | 9 Months Ended |
Sep. 30, 2015 | Sep. 30, 2015 | |
Business Combinations [Abstract] | ||
Acquisition date adjustment | $ 0 | $ 1,380,000 |
Construction Services Redeema50
Construction Services Redeemable Noncontrolling Interests - Additional Information (Detail) - USD ($) $ in Thousands | 1 Months Ended | 9 Months Ended |
Oct. 31, 2014 | Sep. 30, 2015 | |
Additional Paid-in Capital [Member] | ||
Noncontrolling Interest [Line Items] | ||
Adjustment to redemption value | $ 5,777 | |
Principal Previous Owners [Member] | Link-Line and WS Nicholls [Member] | ||
Noncontrolling Interest [Line Items] | ||
Equity interest percentage | 10.00% | |
Description of equity interest | The agreement, associated with that approximate 10% equity interest, provided special dividend rights which entitled the sellers, as holders, to dividends equal to 3.4% of dividends paid at the level of Centuri, and subject to certain conditions, such interests could become exchangeable for a 3.4% equity interest in Centuri. In consideration of the underlying exchange rights of the original agreement, earnings attribution by Centuri to the previous owners has also occurred in an amount equivalent to 3.4% of Centuri earnings since October 2014. During the third quarter of 2015, the sellers formally exercised their exchange rights under the terms of that original agreement. No new rights were conveyed to the noncontrolling parties as a result of the exchange and no new consideration was involved. The ability of the sellers to redeem their holdings for cash at specified dates remains intact. The previous owners may exit their investment retained by requiring the purchase of a portion of their interest commencing July 2017 and in incremental amounts each anniversary date thereafter. The shares subject to the election cumulate (if earlier elections are not made) such that 100% of their interest retained is subject to the election beginning in July 2022. | |
Equity interest dividend rights, percentage of dividends paid by Centuri | 3.40% | |
First redemption date to exchange holdings for cash | 2017-07 | |
Principal Previous Owners [Member] | Link-Line and WS Nicholls [Member] | Construction Services [Member] | ||
Noncontrolling Interest [Line Items] | ||
Equity interest exchangeable percentage in Centuri | 3.40% | |
Percentage of earnings attribution by Centuri to previous owners | 3.40% | |
Principal Previous Owners [Member] | Link-Line and WS Nicholls [Member] | Construction Services [Member] | Maximum [Member] | ||
Noncontrolling Interest [Line Items] | ||
Percentage of retained interest may elect to sell to centuri | 100.00% |
Construction Services Redeema51
Construction Services Redeemable Noncontrolling Interests - Summary of Redeemable Noncontrolling Interest (Detail) $ in Thousands | 9 Months Ended |
Sep. 30, 2015USD ($) | |
Redeemable Noncontrolling Interest [Line Items] | |
Balance | $ 20,042 |
Adjustment to redemption value | 6,738 |
Balance | 13,703 |
Redeemable Noncontrolling Interest (Temporary Equity) [Member] | |
Redeemable Noncontrolling Interest [Line Items] | |
Balance | 20,042 |
Net income attributable to redeemable noncontrolling interest | 454 |
Foreign currency exchange translation adjustment | (55) |
Adjustment to redemption value | (6,738) |
Balance | $ 13,703 |