Document and Entity Information
Document and Entity Information - USD ($) | 12 Months Ended | |
Dec. 31, 2018 | Feb. 21, 2019 | |
Entity Information [Line Items] | ||
Entity Registrant Name | Northwest Pipeline LLC | |
Entity Central Index Key | 110,019 | |
Document Type | 10-K | |
Document Period End Date | Dec. 31, 2018 | |
Amendment Flag | false | |
Document Fiscal Year Focus | 2,018 | |
Document Fiscal Period Focus | FY | |
Current Fiscal Year End Date | --12-31 | |
Entity Shell Company | false | |
Entity Small Business | false | |
Entity Emerging Growth Company | false | |
Entity Filer Category | Non-accelerated Filer | |
Entity Common Stock, Shares Outstanding | 0 | |
Entity Well-known Seasoned Issuer | No | |
Entity Voluntary Filers | No | |
Entity Current Reporting Status | Yes | |
Entity Public Float | $ 0 |
Statement of Comprehensive Inco
Statement of Comprehensive Income - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Operating Revenue | |||
Natural gas transportation | $ 430,730 | $ 460,934 | $ 460,109 |
Natural gas storage | 12,852 | 12,399 | 13,918 |
Other | 36 | 73 | 2 |
Total operating revenues | 443,618 | 473,406 | 474,029 |
OPERATING EXPENSES: | |||
General and administrative | 50,653 | 54,512 | 52,343 |
Operation and maintenance | 75,237 | 78,085 | 79,514 |
Depreciation and amortization | 106,073 | 102,084 | 101,672 |
Regulatory debits | 2,334 | 4,857 | 3,510 |
Taxes, other than income taxes | 17,507 | 17,889 | 17,835 |
Regulatory charge resulting from tax rate change | 35,680 | 206,547 | 0 |
Other expenses, net | 444 | 195 | 0 |
Total operating expenses | 287,928 | 464,169 | 254,874 |
OPERATING INCOME | 155,690 | 9,237 | 219,155 |
OTHER (INCOME) AND OTHER EXPENSES: | |||
Interest expense | 27,987 | 33,015 | 39,164 |
Allowance for equity and borrowed funds used during construction | (2,183) | (1,444) | (1,371) |
Miscellaneous other (income) expenses, net | (1,575) | 5,500 | 907 |
Total other (income) and other expenses | 24,229 | 37,071 | 38,700 |
NET INCOME (LOSS) | 131,461 | (27,834) | 180,455 |
CASH FLOW HEDGES: | |||
Amortization of cash flow hedges into Interest expense | 0 | 0 | (28) |
COMPREHENSIVE INCOME (LOSS) | $ 131,461 | $ (27,834) | $ 180,427 |
Balance Sheet
Balance Sheet - USD ($) $ in Thousands | Dec. 31, 2018 | Dec. 31, 2017 |
CURRENT ASSETS: | ||
Cash | $ 0 | $ 0 |
Receivables: | ||
Trade | 42,143 | 38,884 |
Affiliated companies | 18 | 1,921 |
Advances to affiliate | 180,400 | 137,666 |
Other | 970 | 2,618 |
Materials and supplies | 10,046 | 10,084 |
Exchange gas due from others | 4,581 | 2,720 |
Prepayments and other | 8,591 | 6,423 |
Total current assets | 246,749 | 200,316 |
PROPERTY, PLANT AND EQUIPMENT, at cost | 3,457,982 | 3,396,776 |
Less-Accumulated depreciation | 1,596,369 | 1,508,245 |
Total property, plant and equipment, net | 1,861,613 | 1,888,531 |
OTHER ASSETS: | ||
Deferred charges | 1,277 | 934 |
Regulatory assets | 23,992 | 22,747 |
Total other assets | 25,269 | 23,681 |
Total assets | 2,133,631 | 2,112,528 |
Payables: | ||
Trade | 12,839 | 11,053 |
Affiliated companies | 26,532 | 11,298 |
Accrued liabilities: | ||
Taxes, other than income taxes | 11,496 | 11,617 |
Interest | 5,505 | 3,677 |
Exchange gas due to others | 11,660 | 4,500 |
Exchange gas offset | 0 | 1,499 |
Customer advances | 788 | 2,092 |
Other | 7,386 | 6,655 |
Long-term debt due within one year | 0 | 249,874 |
Total current liabilities | 76,206 | 302,265 |
LONG-TERM DEBT | 576,168 | 331,748 |
OTHER NONCURRENT LIABILITIES: | ||
Asset retirement obligations | 69,350 | 67,100 |
Regulatory liabilities | 290,430 | 246,504 |
Other | 835 | 1,730 |
Total other noncurrent liabilities | 360,615 | 315,334 |
CONTINGENT LIABILITIES AND COMMITMENTS (Note 4) | ||
MEMBER'S EQUITY: | ||
Member's capital | 1,073,892 | 1,073,892 |
Retained earnings | 46,750 | 89,289 |
Total member's equity | 1,120,642 | 1,163,181 |
Total liabilities and member's equity | $ 2,133,631 | $ 2,112,528 |
Statement of Member's Equity St
Statement of Member's Equity Statement of Member's Equity - USD ($) $ in Thousands | Total | MEMBER'S CAPITAL | RETAINED EARINGS | ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) |
Balance at beginning of period at Dec. 31, 2015 | $ 1,073,892 | $ 296,668 | $ 28 | |
Net income (loss) | $ 180,455 | 180,455 | ||
Cash distributions to parent | (174,000) | (174,000) | ||
Reclassification of unrecognized gain into earnings | (28) | (28) | ||
Balance at end of period at Dec. 31, 2016 | 1,377,015 | 1,073,892 | 303,123 | 0 |
Net income (loss) | (27,834) | (27,834) | ||
Cash distributions to parent | (186,000) | (186,000) | ||
Reclassification of unrecognized gain into earnings | 0 | 0 | ||
Balance at end of period at Dec. 31, 2017 | 1,163,181 | $ 1,073,892 | 89,289 | 0 |
Net income (loss) | 131,461 | 131,461 | ||
Cash distributions to parent | (174,000) | (174,000) | ||
Reclassification of unrecognized gain into earnings | 0 | 0 | ||
Balance at end of period at Dec. 31, 2018 | $ 1,120,642 | $ 46,750 | $ 0 |
Statement of Cash Flows
Statement of Cash Flows - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
OPERATING ACTIVITIES: | |||
Net income (loss) | $ 131,461 | $ (27,834) | $ 180,455 |
Adjustments to reconcile net income to net cash provided by (used in) operating activities: | |||
Depreciation | 106,073 | 102,084 | 101,672 |
Regulatory debits | 2,334 | 4,857 | 3,510 |
Regulatory charge resulting from tax rate change | 35,680 | 206,547 | 0 |
Amortization of deferred charges and credits | 954 | 2,687 | 898 |
Allowance for equity funds used during construction | 1,703 | 1,104 | 953 |
Changes in current assets and liabilities: | |||
Trade and other accounts receivable | (1,611) | 1,798 | 845 |
Affiliated receivables | 1,903 | (600) | 120 |
Materials and supplies | 39 | 22 | 77 |
Other current assets | 4,494 | (687) | 424 |
Trade accounts payable | 1,753 | 271 | (1,560) |
Affiliated payables | 15,234 | 4,005 | (4,666) |
Other accrued liabilities | 881 | 1,856 | (2,089) |
Changes in noncurrent assets and liabilities: | |||
Deferred charges | (8,392) | 4,340 | (7,275) |
Regulatory liabilities | 2,530 | 3,503 | 3,785 |
Noncurrent liabilities | 3,498 | (3,620) | 9,025 |
Net cash provided by operating activities | 295,128 | 298,125 | 284,268 |
FINANCING ACTIVITIES: | |||
Proceeds from long-term debt | 246,395 | 249,102 | 0 |
Retirement of long-term debt | (250,000) | (185,000) | (175,000) |
Payments for debt issuance costs | (2,498) | (2,207) | 0 |
Cash distributions to parent | (174,000) | (186,000) | (174,000) |
Net cash used in financing activities | (180,103) | (124,105) | (349,000) |
Property, plant and equipment: | |||
Capital expenditures, net of equity AFUDC | (73,487) | (81,217) | (80,383) |
Contributions and advances for construction costs | 2,075 | 872 | 1,308 |
Disposal of property, plant and equipment, net | (879) | (1,146) | (1,280) |
Advances to affiliates, net | (42,734) | (92,529) | 126,730 |
Proceeds from insurance | 0 | 0 | 18,188 |
Net cash provided by (used in) investing activities | (115,025) | (174,020) | 64,563 |
NET (DECREASE) INCREASE IN CASH | 0 | 0 | (169) |
CASH AT BEGINNING OF PERIOD | 0 | 0 | 169 |
CASH AT END OF PERIOD | 0 | 0 | 0 |
Supplemental Cash Flow Elements [Abstract] | |||
Increases to property, plant and equipment | (73,105) | (80,355) | (72,432) |
Changes in related accounts receivable, accounts payable, and accrued liabilities | (382) | (862) | (7,951) |
Capital expenditures, net of equity AFUDC | $ (73,487) | $ (81,217) | $ (80,383) |
Summary of Significant Accounti
Summary of Significant Accounting Policies (Notes) | 12 Months Ended |
Dec. 31, 2018 | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
Summary of Significant Accounting Policies | SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Corporate Structure and Control Northwest Pipeline LLC (Northwest) was indirectly owned by Williams Partners L.P. (WPZ), a publicly traded Delaware limited partnership, which was consolidated by The Williams Companies, Inc. (Williams). On August 10, 2018, Williams completed a merger with WPZ, pursuant to which Williams acquired all of the publicly held outstanding common units of WPZ in exchange for shares of Williams’ common stock (WPZ Merger). Williams continued as the surviving entity. Northwest is now indirectly owned by Williams. Northwest has no employees. Services are provided to Northwest by Williams and its affiliates. Northwest reimburses Williams and its affiliates for the costs of the employees including compensation and employee benefit plan costs and all related administrative costs. In this report, Northwest is at times referred to in the first person as “we,” “us” or “our.” Nature of Operations We own and operate an interstate pipeline system for the mainline transmission of natural gas. This system extends from the San Juan Basin in northwestern New Mexico and southwestern Colorado through Colorado, Utah, Wyoming, Idaho, Oregon and Washington to a point on the Canadian border near Sumas, Washington. Regulatory Accounting We are regulated by the Federal Energy Regulatory Commission (FERC). The Accounting Standards Codification (ASC) Regulated Operations (Topic 980) provides that rate-regulated public utilities account for and report regulatory assets and liabilities consistent with the economic effect of the way in which regulators establish rates if the rates established are designed to recover the costs of providing the regulated service and if the competitive environment makes it probable that such rates can be charged and collected. Accounting for businesses that are regulated and apply the provisions of Topic 980 can differ from the accounting requirements for non-regulated businesses. Transactions that are recorded differently as a result of regulatory accounting requirements include the capitalization of an equity return component on regulated capital projects, capitalization of other project costs, retirements of general plant assets, employee related benefits, environmental costs, negative salvage, asset retirement obligations, and other costs and taxes included in, or expected to be included in, future rates. As a rate-regulated entity, our management has determined that it is appropriate to apply the accounting prescribed by Topic 980, and, accordingly, the accompanying financial statements include the effects of the types of transactions described above that result from regulatory accounting requirements. In December 2017, the Tax Cuts and Jobs Act (Tax Reform) was enacted, which, among other things, reduced the federal corporate income tax rate from 35 percent to 21 percent. Rates charged to our customers currently permit the recovery of an income tax allowance that includes a deferred income tax component. As a result of the reduced income tax rate from Tax Reform, the WPZ Merger, as well as the collection of historical rates that reflected historical federal and state income tax rates, we expect we will be required to return amounts to certain customers through future rates and have accordingly established federal and state regulatory liabilities of $206.5 million and $12.1 million, respectively, as of December 2018. The timing and actual amount of such return will be subject to future negotiations regarding this matter and many other elements of cost-of-service rate proceedings, including other costs of providing service. Our regulatory asset associated with the effects of deferred taxes on equity funds used during construction was also impacted by Tax Reform and was reduced by $5.7 million in December 2017 through a charge to Miscellaneous other (income) expenses, net below Operating income. Use of Estimates The preparation of financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. Estimates and assumptions which, in the opinion of management, are significant to the underlying amounts included in the financial statements and for which it would be reasonably possible that future events or information could change those estimates include: 1) litigation-related contingencies; 2) environmental remediation obligations; 3) impairment assessments of long-lived assets; 4) depreciation; 5) asset retirement obligations; and 6) regulatory deferred tax. Revenue Recognition (subsequent to adoption of ASC 606) Our customers are comprised of public utilities, municipalities, direct industrial users, electric power generators, and natural gas marketers and producers. A performance obligation is a promise in a contract to transfer a distinct good or service (or integrated package of goods or services) to the customer. A contract’s transaction price is allocated to each distinct performance obligation and recognized as revenue, when, or as, the performance obligation is satisfied. A performance obligation is distinct if the service is separately identifiable from other items in the integrated package of products or services and if a customer can benefit from it on its own or with other resources that are readily available to the customer. Service revenue contracts contain a series of distinct services, with the majority of our contracts having a single performance obligation that is satisfied over time as the customer simultaneously receives and consumes the benefits provided by our performance. Certain customers reimburse us for costs we incur associated with construction of property, plant, and equipment utilized in our operations. As a rate-regulated entity applying Topic 980, we follow FERC guidelines with respect to reimbursement of construction costs. FERC tariffs only allow for cost reimbursement and are non-negotiable in nature; thus, in our judgment, the construction activities do not represent an ongoing major and central operation of our gas pipelines business and are not within the scope of Accounting Standards Update (ASU) 2014-09, Revenues from Contracts with Customers (ASC 606). Accordingly, cost reimbursements are treated as a reduction to the cost of the constructed assets. Service Revenues We are subject to regulation by certain state and federal authorities, including the FERC, with revenue derived from both firm and interruptible transportation and storage contracts. Firm transportation and storage agreements provide for a fixed reservation charge based on the pipeline or storage capacity reserved, and a commodity charge based on the volume of natural gas scheduled, each at rates specified in our FERC tariffs or as negotiated with our customers, with contract terms that are generally long-term in nature. Most of our long-term contracts contain an evergreen provision, which allows the contracts to be extended beyond the specified contract term and until terminated generally by either us or the customer, but in certain cases unilaterally by the customer, with advance notice of termination ranging from one to five years. Interruptible transportation and storage agreements provide for a volumetric charge based on actual commodity transportation or storage utilized in the period in which those services are provided, and the contracts are generally limited to one month periods or less. Our performance obligations include the following: • Firm transportation or storage under firm transportation and storage contracts - an integrated package of services typically constituting a single performance obligation, which includes standing ready to provide such services and receiving, transporting or storing (as applicable), and redelivering commodities; • Interruptible transportation and storage under interruptible transportation and storage contracts - an integrated package of services typically constituting a single performance obligation once scheduled, which includes receiving, transporting or storing (as applicable), and redelivering commodities. In situations where, in our judgment, we consider the integrated package of services as a single performance obligation, which represents a majority of our contracts with customers, we do not consider there to be multiple performance obligations because the nature of the overall promise in the contract is to stand ready (with regard to firm transportation and storage contracts), receive, transport or store, and redeliver natural gas to the customer; therefore, revenue is recognized over time upon satisfaction of our daily stand ready performance obligation. We recognize revenues for reservation charges over the performance obligation period, which is the contract term, regardless of the volume of natural gas that is transported or stored. Revenues for commodity charges from both firm and interruptible transportation services and storage services are recognized based on volumes of natural gas scheduled for delivery at the agreed upon delivery point or based on volumes of natural gas scheduled for injection or withdrawn from the storage facility because they specifically relate to our efforts to provide these distinct services. Generally, reservation charges and commodity charges are recognized as revenue in the same period they are invoiced to our customers. As a result of the ratemaking process, certain amounts collected by us may be subject to refunds upon the issuance of final orders by the FERC in pending rate proceedings. We use judgment to record estimates of rate refund liabilities considering our and other third-party regulatory proceedings, advice of counsel, and other risks. At December 31, 2018 , we had no such rate refund liabilities. In the course of providing transportation services to customers, we may receive different quantities of natural gas from customers than the quantities delivered on behalf of those customers or consumed in fuel to operate our system. The resulting customer imbalances are typically settled through the receipt or delivery of gas in the future based on the timelines outlined in Northwest’s Tariff, whereas the over/under recovery of fuel is cleared up through Northwest’s semi-annual fuel tracker. Customer imbalances to be repaid or recovered in-kind are recorded as Exchange gas due from others or Exchange gas due to others in our Balance Sheet. The under recovery of fuel is recorded as a Regulatory Asset and the over recovery is recorded as a Regulatory Liability. These imbalances are valued at the average of the spot market rates at the Canadian border and the Rocky Mountain market as published in the SNL Financial "Bidweek Index - Spot Rates." Revenue Recognition (prior to the adoption of ASC 606) Our revenues are primarily from services pursuant to long term firm transportation and storage agreements. These agreements provide for a reservation charge based on the volume of contracted capacity and a volumetric charge based on the volume of gas delivered, both at rates specified in our FERC tariffs. We recognize revenues for reservation charges ratably over the contract period regardless of the volume of natural gas that is transported or stored. Revenues for volumetric charges, from both firm and interruptible transportation services and storage injection and withdrawal services, are recognized based on volumes of natural gas scheduled for delivery at the agreed upon delivery point or based on volumes of natural gas scheduled for injection or withdrawal from the storage facility. In the course of providing transportation services to customers, we may receive different quantities of natural gas from customers than the quantities delivered on behalf of those customers or consumed in fuel to operate our system. The resulting customer imbalances are typically settled through the receipt or delivery of gas in the future based on the timelines outlined in Northwest’s Tariff, whereas the over/under recovery of fuel is cleared up through Northwest’s semi-annual fuel tracker. Customer imbalances to be repaid or recovered in-kind are recorded as Exchange gas due from others or Exchange gas due to others in our Balance Sheet. The under recovery of fuel is recorded as a Regulatory Asset and the over recovery is recorded as a Regulatory Liability. These imbalances are valued at the average of the spot market rates at the Canadian border and the Rocky Mountain market as published in the SNL Financial "Bidweek Index - Spot Rates." As a result of the ratemaking process, certain revenues collected by us may be subject to refunds upon the issuance of final orders by the FERC in pending rate proceedings. We record estimates of rate refund liabilities considering our and third-party regulatory proceedings, advice of counsel and other risks. Environmental Matters We are subject to federal, state, and local environmental laws and regulations. Environmental expenditures are expensed or capitalized depending on their economic benefit and potential for rate recovery. We believe that expenditures required to meet applicable environmental laws and regulations are prudently incurred in the ordinary course of business and such expenditures would be permitted to be recovered through rates. Property, Plant, and Equipment Property, plant and equipment (plant), consisting principally of natural gas transmission facilities, is recorded at original cost. The FERC identifies installation, construction and replacement costs that are to be capitalized and included in our asset base for recovery in rates. Routine maintenance, repairs, and renewal costs are charged to income as incurred. Gains or losses from the ordinary sale or retirement of plant are charged or credited to accumulated depreciation; certain other gains or losses are recorded in operating income. We provide for depreciation under the composite (group) method at straight-line FERC prescribed rates that are applied to the cost of the group for transmission and storage facilities. Under this method, assets with similar lives and characteristics are grouped and depreciated as one asset. Included in our depreciation rates is a negative salvage component (net cost of removal) that we currently collect in rates. Our depreciation rates are subject to change each time we file a general rate case with the FERC. Depreciation rates used for major regulated gas plant facilities at December 31, 2018 , 2017 , and 2016 are as follows: Category of Property Storage Facilities 1.60 % — 2.76% Transmission Facilities 2.80 % — 6.97% The incrementally priced Evergreen Expansion Project, which was an expansion of our pipeline system, was placed in service on October 1, 2003. The levelized rate design of this project creates a consistent revenue stream over the related 25-year and 15-year customer contract terms. The related levelized depreciation is lower than book depreciation in the early years and higher than book depreciation in the later years of the contract terms. The depreciation component of the levelized incremental rates will equal the accumulated book depreciation by the end of the primary contract terms. The FERC has approved the accounting for the differences between book depreciation and the Evergreen Expansion Project’s levelized depreciation as a regulatory asset. The levelized period for the 15-year contracts ended September 30, 2018. We recorded regulatory debits totaling $2.3 million in 2018 , $4.9 million in 2017 , and $3.5 million in 2016 in the accompanying Statement of Comprehensive Income (Loss). These debits relate primarily to the levelized depreciation adjustment for the Evergreen Project discussed above. We record a liability and increase the basis in the underlying asset for the present value of each expected future asset retirement obligation (ARO) at the time the liability is initially incurred, typically when the asset is acquired or constructed. Measurement of AROs includes, as a component of future expected costs, an estimate of the price that a third party would demand, and could expect to receive, for bearing the uncertainties inherent in the obligations, sometimes referred to as market-risk premium. We measure changes in the liability due to passage of time by applying an interest method of allocation. This amount is recognized as an increase in the carrying amount of the liability and is offset by a regulatory asset. The gross regulatory asset balances associated with ARO as of December 31, 2018 and 2017 were $86.4 million and $82.2 million, respectively. The regulatory asset is expected to be fully recovered through the net negative salvage component of depreciation included in our rates; as such, the negative salvage component of accumulated depreciation was ($86.4) million and ($82.2) million at December 31, 2018 and 2017 , respectively, and has been reclassified and netted against the amount of the ARO regulatory asset. Impairment of Long-Lived Assets We evaluate long-lived assets for impairment when events or changes in circumstances indicate, in our management’s judgment, that the carrying value of such assets may not be recoverable. When such a determination has been made, our management’s estimate of undiscounted future cash flows attributable to the assets is compared to the carrying value of the assets to determine whether an impairment has occurred. If an impairment of the carrying value has occurred, the amount of the impairment recognized in the financial statements is determined by estimating the fair value of the assets and recording a loss for the amount that the carrying value exceeds the estimated fair value. Judgments and assumptions are inherent in our management’s estimate of undiscounted future cash flows used to determine recoverability of an asset and the estimate of an asset’s fair value used to calculate the amount of impairment to recognize. The use of alternate judgments and/or assumptions could result in the recognition of different levels of impairment charges in the financial statements. Allowance for Funds Used During Construction Allowance for funds used during construction (AFUDC) represents the estimated cost of borrowed and equity funds applicable to utility plant in process of construction and is included as a cost of property, plant and equipment because it constitutes an actual cost of construction under established regulatory practices. The FERC has prescribed a formula to be used in computing separate allowances for borrowed and equity AFUDC. The allowance for borrowed funds used during construction was $0.5 million for 2018 , $0.3 million for 2017 , and $0.4 million for 2016 . The allowance for equity funds was $1.7 million, $1.1 million, and $1.0 million for 2018 , 2017 , and 2016 , respectively. Both are reflected in Other (Income) and Other Expenses . Income Taxes We are a natural gas company organized as a pass-through entity and our taxable income or loss is consolidated on the federal income tax return of our parent, Williams. We generally are treated as a pass-through entity for state and local income tax purposes, and those taxes are generally borne on a consolidated basis by Williams. Net income for financial statement purposes may differ significantly from taxable income of Williams as a result of differences between the tax basis and financial reporting basis of assets and liabilities. Accounts Receivable and Allowance for Doubtful Receivables Accounts receivable are stated at the historical carrying amount net of reserves or write-offs. We do not offer extended payment terms and typically receive payment within one month. We consider receivables past due if full payment is not received by the contractual due date. Our credit risk exposure in the event of nonperformance by the other parties is limited to the face value of the receivables. We perform ongoing credit evaluations of our customers’ financial condition and require collateral from our customers, if necessary. Due to our customer base, we have not historically experienced recurring credit losses in connection with our receivables. Receivables determined to be uncollectible are reserved or written off in the period of determination. Materials and Supplies Inventory All inventories are stated at cost. We determine the cost of the inventories using the average cost method. We perform an annual review of materials and supplies inventories, including an analysis of parts that may no longer be useful due to planned replacements of compressor engines and other components on our system. Based on this assessment, we record a reserve for the value of the inventory which can no longer be used for maintenance and repairs on our pipeline. There was a minimal reserve at December 31, 2018 and 2017 . Deferred Charges We amortize deferred charges over varying periods consistent with the FERC approved accounting treatment and recovery for such deferred items. Unamortized debt expense, debt discount and losses on reacquired long-term debt are amortized by the bonds outstanding method over the related debt repayment periods. Contingent Liabilities We record liabilities for estimated loss contingencies, including environmental matters, when we assess that a loss is probable and the amount of the loss can be reasonably estimated. These liabilities are calculated based upon our assumptions and estimates with respect to the likelihood or amount of loss and upon advice of legal counsel, engineers, or other third parties regarding the probable outcomes of the matters. These calculations are made without consideration of any potential recovery from third-parties. We recognize insurance recoveries or reimbursements from others when realizable. Revisions to these liabilities are generally reflected in income when new or different facts or information become known or circumstances change that affect the previous assumptions or estimates. Pension and Other Postretirement Benefits We do not have employees. Certain of the costs charged to us by Williams associated with employees who directly support us include costs related to Williams’ pension and other postretirement benefit plans. (See Note 6 for further discussion.) Although the underlying benefit plans of Williams are single-employer plans, we follow multiemployer plan accounting whereby the amount charged to us, and thus paid by us, is based on our share of net periodic benefit cost. Cash Flows from Operating Activities and Cash Equivalents We use the indirect method to report cash flows from operating activities, which requires adjustments to net income to reconcile to net cash flows provided by operating activities. We include short-term, highly-liquid investments that have an original maturity of three months or less as cash equivalents. Interest Payments Cash payments for interest, net of interest capitalized, were $25.4 million in 2018 , $31.9 million in 2017 , and $38.5 million in 2016 . Accounting Standards Issued and Adopted In May 2014, the Financial Accounting Standards Board (FASB) issued ASU 2014-09 establishing ASC 606. ASC 606 establishes a comprehensive new revenue recognition model designed to depict the transfer of goods or services to a customer in an amount that reflects the consideration the entity expects to be entitled to receive in exchange for those goods or services and requires significantly enhanced revenue disclosures. In August 2015, the FASB issued ASU 2015-14 “Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date” (ASU 2015-14). Per ASU 2015-14, the standard became effective for interim and annual reporting periods beginning after December 15, 2017. We adopted the provisions of ASC 606 effective January 1, 2018, utilizing the modified retrospective transition method for all contracts with customers, which included applying the provisions of ASC 606 beginning January 1, 2018, to all contracts not completed as of that date. There was no cumulative effect adjustment to retained earnings upon initially applying ASC 606 for periods prior to January 1, 2018. For each revenue contract type, we conducted a formal contract review process to evaluate the impact of ASC 606. As a result of the adoption of ASC 606, there are no changes to the timing of our revenue recognition or differences in the presentation in our financial statements from those under the previous revenue standard (See Note 2). Accounting Standards Issued But Not Yet Adopted In June 2016, the FASB issued ASU 2016-13 “Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments” (ASU 2016-13). ASU 2016-13 changes the impairment model for most financial assets and certain other instruments. For trade and other receivables, held-to-maturity debt securities, loans, and other instruments, entities will be required to use a new forward-looking “expected loss” model that generally will result in the earlier recognition of allowances for losses. The guidance also requires increased disclosures. ASU 2016-13 is effective for interim and annual periods beginning after December 15, 2019. Early adoption is permitted. The standard requires varying transition methods for the different categories of amendments. We do not expect ASU 2016-13 to have a significant impact on our financial statements. In February 2016, the FASB issued ASU 2016-02 “Leases (Topic 842)” (ASU 2016-02). ASU 2016-02 establishes a comprehensive new lease accounting model. ASU 2016-02 modifies the definition of a lease, requires a dual approach to lease classification similar to current lease accounting, and causes lessees to recognize operating leases on the balance sheet as a lease liability measured as the present value of the future lease payments with a corresponding right-of-use asset, with an exception for leases with a term of one year or less. Additional disclosures will also be required regarding the amount, timing, and uncertainty of cash flows arising from leases. In January 2018, the FASB issued ASU 2018-01 “Leases (Topic 842): Land Easement Practical Expedient for Transition to Topic 842” (ASU 2018-01). Per ASU 2018-01, land easements and rights-of-way are required to be assessed under ASU 2016-02 to determine whether the arrangements are or contain a lease. ASU 2018-01 permits an entity to elect a transition practical expedient to not apply ASU 2016-02 to land easements that exist or expired before the effective date of ASU 2016-02 and that were not previously assessed under the previous lease guidance in ASC Topic 840 “Leases.” In July 2018, the FASB issued ASU 2018-11 “Leases (Topic 842): Targeted Improvements” (ASU 2018-11). Prior to ASU 2018-11, a modified retrospective transition was required for financing or operating leases existing at or entered into after the beginning of the earliest comparative period presented in the financial statements. ASU 2018-11 allows entities an additional transition method to the existing requirements whereby an entity could adopt the provisions of ASU 2016-02 by recognizing a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption without adjustment to the financial statements for periods prior to adoption. ASU 2018-11 also allows a practical expedient that permits lessors to not separate non-lease components from the associated lease component if certain conditions are present. ASU 2016-02 is effective for interim and annual periods beginning after December 15, 2018. Early adoption is permitted. We adopted ASU 2016-02 effective January 1, 2019. We are substantially complete with our review of contracts to identify leases based on the modified definition of a lease and changes to our internal controls to support management in the accounting for and disclosure of leasing activities upon adoption of ASU 2016-02. We implemented a financial lease accounting system to assist management in the accounting for leases upon adoption. We are substantially complete with the implementation of ASU 2016-02 and believe the most significant changes to our financial statements relate to the recognition of a lease liability and offsetting right-of-use asset in our Balance Sheet for operating leases, which we estimate to be less than 3 percent of total liabilities and total assets. We have also evaluated ASU 2016-02’s available practical expedients on adoption. We generally elected to adopt the practical expedients, which includes the practical expedient to not separate lease and non-lease components by both lessees and lessors by class of underlying assets and the land easements practical expedient. |
Rate and Regulatory Matters (No
Rate and Regulatory Matters (Notes) | 12 Months Ended |
Dec. 31, 2018 | |
Public Utilities, Rate Matters [Abstract] | |
Public Utilities, Disclosure of Rate Matters [Text Block] | RATE AND REGULATORY MATTERS Rate Case Settlement Filing On January 23, 2017, we filed for FERC approval a Stipulation and Settlement Agreement (Settlement) and were assigned Docket No. RP17-346. The Settlement specified an annual cost of service of $440 million and established a new general system firm Rate Schedule TF-1 (Large Customer) demand rate of $0.39294/Dth with a $0.00832 commodity rate (Phase 1) and a demand rate of $0.39033/Dth with a $0.00832 commodity rate (Phase 2). Phase 1 rates became effective January 1, 2018 and Phase 2 rates became effective October 1, 2018. The annual cost of service did not change from Phase 1 to Phase 2, but the Phase 2 rates reflect the termination of fifteen-year levelized contracts which became Rate Schedule TF-1 (Large Customer) contracts. Provisions were included in the Settlement that we can file a general rate case to place new rates into effect after October 1, 2018, and that a general rate case must be filed for new rates to become effective no later than January 1, 2023. Tax Reform Rates charged to our customers are subject to the rate-making policies of the FERC. These policies permit an interstate pipeline to include in its cost-of-service an income tax allowance that includes a deferred income tax component. Tax Reform, among other things, reduced the corporate federal income tax rates. As part of our Settlement discussed above, we agreed with our customers to record a regulatory asset or liability for federal income tax rate increases or decreases due to subsequent legislation, such as Tax Reform. Therefore, we have established a regulatory liability of $23.6 million plus accrued interest of $0.5 million, as of December 31, 2018, included within Regulatory Liabilities in our Balance Sheet. This liability will be amortized over a five-year period, coincidental with the next rate case going into effect. As a result of the WPZ Merger, we also recorded a $12.1 million state tax regulatory liability associated with a decrease in our estimated state income tax rate. FERC Developments On March 15, 2018, the FERC issued a revised policy statement (the March 15 Statement) in Docket No. PL17-1 regarding the recovery of income tax costs in rates of natural gas pipelines. The FERC found that an impermissible double recovery results from granting a Master Limited Partnership (MLP) pipeline both an income tax allowance and a return on equity pursuant to the discounted cash flow methodology. As a result, the FERC will no longer permit an MLP pipeline to recover an income tax allowance in its cost of service. The FERC further stated it will address the application of this policy to non-MLP partnership forms as those issues arise in subsequent proceedings. One of the benefits of the WPZ Merger is to allow us to continue to recover an income tax allowance in our cost of service rates. On July 18, 2018, the FERC issued an order dismissing the requests for rehearing and clarification of the revised policy statement. In addition, the FERC provided guidance that an MLP pipeline (or other pass-through entity) no longer recovering an income tax allowance pursuant to the revised policy may eliminate previously accumulated deferred income taxes (ADIT) from its cost of service instead of flowing these previously accumulated ADIT balances to ratepayers. This guidance, if implemented, would significantly mitigate the impact of the March 15 Statement. However, the FERC stated that the revised policy statement and such guidance do not establish a binding rule, but are instead expressions of general policy intent designed to provide guidance by notifying entities of the course of action the FERC intends to follow in future adjudications. To the extent the FERC addresses these issues in future proceedings, it will consider any arguments regarding not only the application of the revised policy to the facts of the case, but also any arguments regarding the underlying validity of the policy itself. The FERC's guidance on ADIT likely will be challenged by customers and state commissions, which would result in a long period of revenue uncertainty for pipelines eliminating ADIT from their cost of service. The WPZ Merger has the additional benefit of eliminating this uncertainty. On March 15, 2018, the FERC also issued a Notice of Proposed Rulemaking in Docket No. RM18-11 proposing a filing process that will allow it to determine which natural gas pipelines may be collecting unjust and unreasonable rates in light of the reduction in the corporate income tax rate in Tax Reform and the revised policy statement. On July 18, 2018, the FERC issued a Final Rule in the docket, retaining the filing requirement and reaffirming the options that pipelines have to either reflect the reduced tax rate or explain why no rate change is necessary. The FERC also clarified that a natural gas company organized as a pass-through entity all of whose income or losses are consolidated on the federal income tax return of its corporate parent is considered to be subject to the federal corporate income tax, and is thus eligible for a tax allowance. We believe this Final Rule and the previously discussed WPZ Merger allow for the continued recovery of income tax allowances in Northwest Pipeline’s rates. On October 19, 2018, we filed in Docket No. RP19-106, a petition requesting that the Commission waive our FERC Form No. 501-G filing requirement under this Final Rule because the reduction in the corporate income tax in Tax Reform is already addressed in our Settlement. On November 19, 2018 FERC granted our waiver request, obviating the need to make a FERC Form No. 501-G filing. On March 15, 2018, the FERC also issued a Notice of Inquiry in Docket No. RM18-12 seeking comments on the additional impacts of Tax Reform on jurisdictional rates, particularly whether, and if so how, the FERC should address changes relating to ADIT amounts after the corporate income tax rate reduction and bonus depreciation rules, as well as whether other features of Tax Reform require FERC action. We are evaluating the impact of these developments and currently expect any associated impacts would be prospective and determined through subsequent rate proceedings. We also continue to monitor developments that may impact our regulatory liabilities resulting from Tax Reform. It is reasonably possible that our future tariff-based rates collected may be adversely impacted. |
Contingent Liabilities and Comm
Contingent Liabilities and Commitments (Notes) | 12 Months Ended |
Dec. 31, 2018 | |
Commitments and Contingencies Disclosure [Abstract] | |
Contingent Liabilities and Commitments | CONTINGENT LIABILITIES AND COMMITMENTS Environmental Matters We are subject to the National Environmental Policy Act and other federal and state legislation regulating the environmental aspects of our business. Except as discussed below, our management believes that we are in substantial compliance with existing environmental requirements. Environmental expenditures are expensed or capitalized depending on their future economic benefit and potential for rate recovery. We believe that, with respect to any expenditures required to meet applicable standards and regulations, the FERC would grant the requisite rate relief so that substantially all of such expenditures would be permitted to be recovered through rates. Beginning in the mid-1980s, we evaluated many of our facilities for the presence of toxic and hazardous substances to determine to what extent, if any, remediation might be necessary. We identified polychlorinated biphenyl (PCB) contamination in air compressor systems, soils, and related properties at certain compressor station sites. Similarly, we identified hydrocarbon impacts at these facilities due to the former use of earthen pits, lubricating oil leaks or spills, and excess pipe coating released to the environment. In addition, heavy metals have been identified at these sites due to the former use of mercury containing meters and paint and welding rods containing lead, cadmium, and arsenic. The PCBs were remediated pursuant to a Consent Decree with the U.S. Environmental Protection Agency (EPA) in the late 1980s, and we conducted a voluntary clean-up of the hydrocarbon and mercury impacts in the early 1990s. In 2005, the Washington Department of Ecology required us to re-evaluate our previous clean-ups in Washington. During 2006 to 2015, 129 meter stations were evaluated, of which 82 required remediation. As of December 31, 2018 , all of the meter stations have been remediated. During 2006 to 2018, 14 compressor stations were evaluated, of which 11 required remediation. As of December 31, 2018, 10 compressor stations have been remediated. On the basis of the findings to date, we estimate that environmental assessment and remediation costs will total approximately $2.0 million, measured on an undiscounted basis, and are expected to be incurred through 2026. At December 31, 2018 we had accrued liabilities totaling approximately $2.0 million, $1.3 million in current liabilities and $0.7 million in other noncurrent liabilities and at December 31, 2017 approximately $3.0 million, $1.3 million in current liabilities and $1.7 million in other noncurrent liabilities for these costs. We are conducting environmental assessments and implementing a variety of remedial measures that may result in increases or decreases in the total estimated costs. The EPA and various state regulatory agencies routinely promulgate and propose new rules, and issue updated guidance to existing rules. These rulemakings include, but are not limited to, rules for reciprocating internal combustion engine maximum achievable control technology, air quality standards for one-hour nitrogen dioxide emissions, and volatile organic compound and methane new source performance standards impacting design and operation of storage vessels, pressure valves, and compressors. The EPA previously issued its rule regarding National Ambient Air Quality Standards for ground-level ozone. We are monitoring the rule’s implementation as it will trigger additional federal and state regulatory actions that may impact our operations. Implementation of the regulations is expected to result in impacts to our operations and increase the cost of additions to Property, plant, and equipment - net in the Balance Sheet for both new and existing facilities in affected areas. We are unable to reasonably estimate the cost of additions that may be required to meet the regulations at this time due to uncertainty created by various legal challenges to these regulations and the need for further specific regulatory guidance. Other Matters Various other proceedings are pending against us and are considered incidental to our operations. Summary We estimate that for all matters for which we are able to reasonably estimate a range of loss, including those noted above and others that are not individually significant, our aggregate reasonably possible losses beyond amounts accrued for all of our contingent liabilities are immaterial to our expected future annual results of operations, liquidity and financial position. These calculations have been made without consideration of any potential recovery from third-parties. We have disclosed all significant matters for which we are unable to reasonably estimate a range of possible loss. |
Debt, Financing Arrangements, a
Debt, Financing Arrangements, and Leases (Notes) | 12 Months Ended |
Dec. 31, 2018 | |
Debt Disclosure [Abstract] | |
Debt, Financing Arrangements, and Leases | DEBT, FINANCING ARRANGEMENTS, AND LEASES Long-Term Debt Long-term debt, presented net of unamortized discount and unamortized debt issuance costs, consists of the following: December 31, 2018 2017 (Thousands of Dollars) 6.05% senior unsecured notes due 2018 $ — $ 250,000 7.125% unsecured debentures due 2025 85,000 85,000 4.0% unsecured debentures due 2027 500,000 250,000 Debt issuance costs (4,507 ) (2,415 ) Unamortized debt discount (4,325 ) (963 ) Total long-term debt, including current portion 576,168 581,622 Long-term debt due within one year — 249,874 Total long-term debt less current portion $ 576,168 $ 331,748 There are no maturities applicable to long-term debt outstanding through 2023. No property is pledged as collateral under any of our long-term debt. Restrictive Debt Covenants At December 31, 2018 , none of our debt instruments restrict the amount of distributions to our parent, provided, however, that under the credit facility described below, we are restricted from making distributions to our parent during an event of default if we have directly incurred indebtedness under the credit facility. Our debt agreements contain restrictions on our ability to incur secured debt beyond certain levels. Issuance and Retirement of Long-Term Debt On August 24, 2018, we issued $250 million of 4.0 percent senior unsecured notes due 2027 to investors in a private debt placement. We used the net proceeds to repay the intercompany debt owed to Williams in connection with the repayment of our 6.05 percent senior notes at their maturity on June 15, 2018 and for general corporate purposes. The notes, which are an additional issuance of the 4.0 percent senior unsecured notes due 2027 we originally issued on April 3, 2017 and subsequently exchanged for substantially identical registered notes, were issued under the Indenture, dated as of April 3, 2017, between us and The Bank of New York Mellon Trust Company, N.A., as trustee. As part of the issuance we entered into a registration rights agreement with the initial purchasers of the notes. Under the terms of the agreement, we were obligated to file and consummate a registration statement for an offer to exchange the notes for a new issue of substantially identical notes registered under the Securities Act within 365 days after closing and to use commercially reasonable efforts to complete the exchange offer. We filed a registration statement, which was subsequently declared effective by the SEC, and consummated the exchange offer in the fourth quarter of 2018. On April 3, 2017, we issued $250 million of 4.0 percent senior unsecured notes due 2027 to investors in a private debt placement. We used the net proceeds to retire $185 million of 5.95 percent senior unsecured notes that matured on April 15, 2017, and for general corporate purposes. We filed a registration statement, which the SEC declared effective in January 2018, and consummated the exchange offer in the first quarter of 2018. Credit Facility On July 13, 2018, we, along with Williams and Transco (the “borrowers”), the lenders named therein, and an administrative agent entered into a Credit Agreement with aggregate commitments available of $4.5 billion, with up to an additional $500 million increase in aggregate commitments available under certain circumstances. We and Transco are each subject to a $500 million borrowing sublimit. The facility made available under the Credit Agreement is initially available for five years from the Credit Agreement Effective Date (the “Maturity Date”). The borrowers may request an extension of the Maturity Date for an additional one-year period up to two times, to allow a Maturity Date as late as the seventh anniversary of the Credit Agreement Effective Date, subject to certain conditions. The Credit Agreement allows for same day swingline borrowings up to an aggregate amount of $200 million, subject to other utilization of the aggregate commitments under the Credit Agreement. Letter of credit commitments of $1.0 billion are, subject to the $500 million borrowing sublimit applicable to us and Transco, available to the borrowers. At December 31, 2018, no letters of credit have been issued and loans to Williams of $160 million were outstanding under the credit facility. Measured as of December 31, 2018, we are in compliance with our financial covenant under the credit facility. Various covenants may limit, among other things, a borrower’s and its material subsidiaries’ ability to grant certain liens supporting indebtedness, merge or consolidate, sell all or substantially all of its assets, enter into certain affiliate transactions, make certain distributions during an event of default, enter into certain restrictive agreements, and allow any material change in the nature of its business. If an event of default with respect to a borrower occurs under the credit facility, the lenders will be able to terminate the commitments for the respective borrowers and accelerate the maturity of any loans of the defaulting borrower under the credit facility agreement and exercise other rights and remedies. Other than swing line loans, each time funds are borrowed, the applicable borrower may choose from two methods of calculating interest: a fluctuating base rate equal to Citibank N.A.'s alternate base rate plus an applicable margin or a periodic fixed rate equal to the London Interbank Offered Rate plus an applicable margin. We are required to pay a commitment fee based on the unused portion of the credit facility. The applicable margin and the commitment fee are determined by reference to a pricing schedule based on the applicable borrower's senior unsecured long-term debt ratings. Williams participates in a commercial paper program, and Williams management considers amounts outstanding under this program to be a reduction of available capacity under the credit facility. The program allows a maximum outstanding amount at anytime of $4 billion of unsecured commercial paper notes. At December 31, 2018 , Williams had no outstanding commercial paper. Lease Obligations Our leasing arrangements include mostly premise and equipment leases that are classified as operating leases. Effective October 1, 2009, we entered into an agreement to lease office space from a third party. The agreement had an initial term of approximately 10 years, and in May 2018 was renewed for an additional 10 years, expiring December 31, 2029. Following are the estimated future minimum annual rental payments required under operating leases, which have initial or remaining noncancelable lease terms in excess of one year: (Thousands of Dollars) 2019 $ 1,942 2020 1,968 2021 1,920 2022 1,909 2023 1,832 Thereafter 11,508 Total $ 21,079 Operating lease rental expense, net of sublease revenues, amounted to $2.8 million, $3.5 million, and $2.7 million for 2018 , 2017 , and 2016 , respectively. |
Employee Benefit Plans (Notes)
Employee Benefit Plans (Notes) | 12 Months Ended |
Dec. 31, 2018 | |
Retirement Benefits [Abstract] | |
Employee Benefit Plans [Text Block] | BENEFIT PLANS Certain of the benefit costs charged to us by Williams associated with employees who directly support us are described below. Additionally, allocated corporate expenses from Williams to us also include amounts related to these same employee benefits, which are not included in the amounts presented below. (See Note 8 for further discussion.) Pension and Other Postretirement Benefit Plans Williams has noncontributory defined benefit pension plans (Williams Pension Plan, Williams Inactive Employees Pension Plan, and The Williams Companies Retirement Restoration Plan) that provide pension benefits for its eligible employees. Pension costs charged to us by Williams was $3.9 million in 2018 , $5.2 million in 2017 , and $2.3 million in 2016 . Included in our pension costs are settlement charges of $1.3 million and $3.0 million for 2018 and 2017, respectively. This amount reflects the portion of Williams’ settlement charge directly charged to us which was required as a result of lump-sum benefit payments made under Williams’ program to pay out certain deferred vested pension benefits, as well as lump-sum benefit payments made throughout 2018 and 2017. In addition, we were charged $0.7 million and $1.1 million for 2018 and 2017, respectively, of allocated corporate expenses associated with the settlement charge. Williams provides subsidized retiree health care and life insurance benefits to certain eligible participants. Generally, participants that were employed by Williams on or before December 31, 1991 are eligible for subsidized retiree health care benefits. During 2018 , 2017 , and 2016 , we received credits from Williams related to retiree health care and life insurance benefits of $2.1 million , $3.5 million and $3.8 million , respectively. These credits were recorded as regulatory liabilities. We have been allowed by rate case settlements to collect or refund in future rates any differences between the actuarially determined costs and amounts currently being recovered in rates related to other postretirement benefits. Any difference between the annual actuarially determined cost and amounts currently being recovered in rates are recorded as regulatory assets or liabilities and collected or refunded through future rate adjustments. The amount of other postretirement benefits costs deferred as a regulatory liability at December 31, 2018 and 2017 are $36.2 million and $34.1 million , respectively. Defined Contribution Plan Williams maintains a defined contribution plan for substantially all of its employees. Williams charged us compensation expense of $1.9 million in 2018 , $2.1 million in 2017 , and $2.2 million in 2016 for Williams’ company matching contributions to this plan. Employee Stock-Based Compensation Plan Information The Williams Companies, Inc. 2007 Incentive Plan, as subsequently amended and restated (Plan), provides for Williams’ common stock-based awards to both employees and nonmanagement directors. The Plan permits the granting of various types of awards including, but not limited to, restricted stock units and stock options. Awards may be granted for no consideration other than prior and future services or based on certain financial performance targets achieved. Williams currently bills us directly for compensation expense related to stock-based compensation awards based on the fair value of the awards. We are also billed for our proportionate share of Williams’ and other affiliates’ stock-based compensation expense through various allocation processes. Total stock-based compensation expense for the years ended December 31, 2018 , 2017 and 2016 was $1.8 million , $1.9 million and $1.4 million , respectively, excluding amounts allocated from WPZ and Williams. |
Financial Instruments (Notes)
Financial Instruments (Notes) | 12 Months Ended |
Dec. 31, 2018 | |
Fair Value Disclosures [Abstract] | |
Financial Instruments | FINANCIAL INSTRUMENTS Fair Value of Financial Instruments The following methods and assumptions were used to estimate the fair value of each class of financial instruments for which it is practicable to estimate that value: Cash and advances to affiliate —The carrying amounts approximate fair value, because of the short-term nature of these instruments. Long-term debt – The disclosed fair value of our long-term debt, which we consider as a level 2 measurement, is determined by a market approach using broker quoted indicative period-end bond prices. The quoted prices are based on observable transactions in less active markets for our debt or similar instruments. The carrying amount and estimated fair value of our long-term debt, including current maturities, were $576.2 million and $577.1 million , respectively, at December 31, 2018 , and $581.6 million and $606.8 million , respectively, at December 31, 2017 . |
Transactions with Major Custome
Transactions with Major Customers and Affiliates (Notes) | 12 Months Ended |
Dec. 31, 2018 | |
Transactions with Major Customers and Affiliates [Abstract] | |
Transactions with Major Customers and Affiliates | TRANSACTIONS WITH MAJOR CUSTOMERS AND AFFILIATES Major Customers During the periods presented, more than 10 percent of our operating revenues were generated from each of the following customers: Years Ended December 31, 2018 2017 2016 (Thousands of Dollars) Puget Sound Energy, Inc. $ 115,238 $ 120,226 $ 120,351 Northwest Natural Gas Company 49,126 51,743 49,895 Cascade Natural Gas Corporation 46,164 48,071 47,951 Our major customers are located in the Pacific Northwest. As a general policy, collateral is not required for receivables, but customers’ financial condition and credit worthiness are regularly evaluated and historical collection losses have been minimal. Related Party Transactions We are a participant in Williams’ cash management program. At December 31, 2018 and 2017 , the advances due to us by Williams totaled approximately $180.4 million and $137.7 million, respectively. These advances are represented by demand notes and are classified as Receivables - Advances to Affiliate in the accompanying Balance Sheet. The interest rate on these intercompany demand notes is based upon the daily overnight investment rate paid on Williams’ excess cash at the end of each month, which was approximately 2.24 percent at December 31, 2018 . The interest income from these advances was $2.0 million for the year ended December 31, 2018 , and minimal for the years ended December 31, 2017 , and 2016 . Such interest income is included in Other (Income) and Other Expenses: Miscellaneous other (income) expenses, net on the accompanying Statement of Comprehensive Income. We have no employees. Services necessary to operate our business are provided to us by Williams and certain affiliates of Williams. We reimburse Williams and its affiliates for all direct and indirect expenses incurred or payments made (including salary, bonus, incentive compensation, and benefits) in connection with these services. Employees of Williams also provide general administrative and management services to us, and we are charged for certain administrative expenses incurred by Williams. These charges are either directly identifiable or allocated to our assets. Direct charges are for goods and services provided by Williams at our request. Allocated charges are based on a three factor formula, which considers revenues; property, plant, and equipment; and payroll. In management’s estimation, the allocation methodologies used are reasonable and result in a reasonable allocation to us of our costs of doing business incurred by Williams. We were billed $92.7 million , $96.5 million , and $92.8 million in the years ended December 31, 2018 , 2017 , and 2016 , respectively, for these services. Such expenses are primarily included in General and administrative and Operation and maintenance expenses on the accompanying Statement of Comprehensive Income (Loss). The amount billed to us during 2016 includes $2.4 million for severance and other related costs associated with a reduction in workforce primarily recognized in the first quarter. During 2018 , 2017 , and 2016 , we declared and paid cash distributions to our parent of $174.0 million , $186.0 million , and $174.0 million , respectively. During January 2019, we declared and paid cash distributions of $21.0 million to our parent. |
Asset Retirement Obligations (N
Asset Retirement Obligations (Notes) | 12 Months Ended |
Dec. 31, 2018 | |
Asset Retirement Obligation Disclosure [Abstract] | |
Asset Retirement Obligations | ASSET RETIREMENT OBLIGATIONS Our accrued asset retirement obligations relate to our gas storage and transmission facilities. At the end of the useful life of our facilities, we are legally obligated to remove or plug and abandon certain transmission facilities including underground pipelines, major river spans, compressor stations and meter station facilities. These obligations also include restoration of the property sites after removal of the facilities from above and below the ground. During 2018 and 2017 , our overall asset retirement obligation changed as follows (in thousands): 2018 2017 Beginning balance $ 67,100 $ 60,762 Accretion 4,359 3,968 New obligations — 149 Changes in estimates of existing obligations (1) (2,095 ) 2,510 Property dispositions/obligations settled (14 ) (289 ) Ending balance $ 69,350 $ 67,100 (1) Changes in estimates of existing obligations are primarily due to the annual review process, which considers various factors including inflation rates, current estimates for removal costs, the estimated remaining life of assets, and discount rates. |
Regulatory Assets and Liabiliti
Regulatory Assets and Liabilities (Notes) | 12 Months Ended |
Dec. 31, 2018 | |
Regulatory Assets and Liabilities Disclosure [Abstract] | |
Regulatory Assets and Liabilities | REGULATORY ASSETS AND LIABILITIES Our regulatory assets and liabilities result from our application of the provisions of ASC Topic 980 and are reflected on our Balance Sheet. Current regulatory assets are included in Prepayments and other . Current regulatory liabilities are included in Exchange gas offset . These balances are presented on our Balance Sheet on a gross basis and are recoverable or refundable over various periods. Below are the details of our regulatory assets and liabilities as of December 31, 2018 and 2017 : 2018 2017 (Thousands of Dollars) Current regulatory assets: Levelized depreciation $ 414 $ 4,707 Fuel Recovery 6,619 — Total current regulatory assets 7,033 4,707 Noncurrent regulatory assets: Grossed-up deferred taxes on equity funds used during construction 5,883 6,598 Levelized depreciation 18,109 16,149 Total noncurrent regulatory assets 23,992 22,747 Total regulatory assets $ 31,025 $ 27,454 Current regulatory liabilities: Fuel recovery $ — $ 1,539 Noncurrent regulatory liabilities: Postretirement benefits 36,154 34,089 Deferred federal taxes-liability 206,527 206,547 Deferred state taxes - liability 12,120 — Customer tax refund 24,094 — Asset retirement obligations, net 11,535 5,868 Total noncurrent regulatory liabilities 290,430 246,504 Total regulatory liabilities $ 290,430 $ 248,043 The significant regulatory assets and liabilities include: Levelized Depreciation Levelized depreciation allows contract revenue streams to remain constant over the primary contract terms by recognizing lower than book depreciation in the early years and higher than book depreciation in later years. The depreciation component of the levelized incremental rates will equal the accumulated book depreciation by the end of the primary contract terms. The difference between levelized depreciation and straight-line book depreciation is recorded as a FERC approved regulatory asset or liability and is eliminated over the levelization period. Fuel Recovery These amounts reflect the value of the cumulative volumetric difference between the gas retained from our customers and the gas consumed in operations. These amounts are not included in the rate base, but are expected to be recovered or refunded by changing the fuel reimbursement factor in subsequent fuel filings. Grossed-Up Deferred Taxes on Equity Funds Used During Construction The regulatory asset balance was established to offset the deferred tax for the equity component of the allowance for funds used during the construction of long-lived assets. All amounts were generated during the period that we were a taxable entity. Taxes on capitalized funds used during construction and the offsetting deferred income taxes are included in the rate base and are recovered over the depreciable lives of the long-lived asset to which they relate. Postretirement Benefits We seek to recover the actuarially determined cost of postretirement benefits through rates that are set through periodic general rate filings. Any differences between the annual actuarially determined cost and amounts currently being recovered in rates are recorded as regulatory assets or liabilities and collected or refunded through future rate adjustments. These amounts are not included in the rate base, and we are not currently recovering postretirement benefit costs in our rates. (See Note 6) Deferred Federal Taxes-Liability This r e gulatory liability balance was established as a result of a decrease to rate base deferred taxes due to a decrease to the effective federal income tax rate. The timing of the refund of the regulatory liability to rate payers will be subject to future discussions and negotiations with our customers in our next rate case. Asset Retirement Obligations, net This regulatory liability balance reflects the amount that we have recovered in our rates related to our future retirement costs offset by depreciation of the ARO asset and changes in the ARO liability due to the passage of time. AROs are expected to be fully recovered through the net negative salvage component of depreciation included in our rates. (See Note 9 for further discussion) Customer Tax Refund In our 2017 Settlement, which became effective January 1, 2018, we agreed with our customers that if federal income tax rates decreased due to subsequent legislation, such as Tax Reform enacted in 2017, we would record a regulatory liability. As a result of Tax Reform, the regulatory liability will be $23.6 million annually plus accrued interest ($0.5 million at December 31, 2018) for the period beginning January 1, 2018 and continuing through the time that our current rates remain effective. (See Note 3) Deferred State Taxes-Liability This regulatory liability balance, following the WPZ Merger, reflects a decrease to rate base deferred taxes due to a decrease to the estimated effective state income tax rates. The timing of the refund of the regulatory liability to rate payers will be subject to future discussions and negotiations with our customers in our next rate case. |
Revenue Recognition Revenue Rec
Revenue Recognition Revenue Recognition (Notes) | 12 Months Ended |
Dec. 31, 2018 | |
Revenue Recognition [Abstract] | |
Revenue from Contract with Customer [Text Block] | REVENUE RECOGNITION Revenue by Category Our revenue disaggregation by major service line includes Natural gas transportation , Natural gas storage , and Other, which are separately presented on the Statement of Comprehensive Income (Loss) . We do not have any contract assets or material contract liabilities. Remaining Performance Obligations The following table presents the transaction price allocated to the remaining performance obligations under certain contracts as of December 31, 2018 . These primarily include reservation charges on contracted capacity on our firm transportation and storage contracts with customers. Amounts from certain contracts included in the table below, which are subject to the periodic review and approval by the FERC, reflect the rates for such services in our current FERC tariffs for the life of the related contracts; however, these rates may change based on future rate cases or settlements approved by the FERC and the amount and timing of these changes is not currently known. As a practical expedient permitted by ASC 606, this table excludes the variable consideration component for commodity charges that will be recognized in future periods. As noted above, certain of our contracts contain evergreen provisions for periods beyond the initial term of the contract. The remaining performance obligations as of December 31, 2018 , does not consider potential future performance obligations for which the renewal has not been exercised. The table below also does not include contracts with customers for which the underlying facilities have not received FERC authorization to be placed into service. (Thousands) 2019 $ 427,705 2020 404,899 2021 378,288 2022 372,446 2023 329,338 Thereafter 1,832,771 Total $ 3,745,447 The table above excludes remaining performance obligations associated with certain contract extensions executed in February 2019. The additional performance obligations associated with these contract extensions are approximately $11 million in 2023 and $549 million thereafter. Receivables from contracts with customers are included within Receivables - Trade and Receivables - Affiliated companies and receivables that are not related to contracts with customers comprise the balance of Receivables - Advances to affiliate and Receivables - Other in our Balance Sheet. |
Summary of Significant Accoun_2
Summary of Significant Accounting Policies (Policies) | 12 Months Ended |
Dec. 31, 2018 | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
Regulatory Accounting | Regulatory Accounting We are regulated by the Federal Energy Regulatory Commission (FERC). The Accounting Standards Codification (ASC) Regulated Operations (Topic 980) provides that rate-regulated public utilities account for and report regulatory assets and liabilities consistent with the economic effect of the way in which regulators establish rates if the rates established are designed to recover the costs of providing the regulated service and if the competitive environment makes it probable that such rates can be charged and collected. Accounting for businesses that are regulated and apply the provisions of Topic 980 can differ from the accounting requirements for non-regulated businesses. Transactions that are recorded differently as a result of regulatory accounting requirements include the capitalization of an equity return component on regulated capital projects, capitalization of other project costs, retirements of general plant assets, employee related benefits, environmental costs, negative salvage, asset retirement obligations, and other costs and taxes included in, or expected to be included in, future rates. As a rate-regulated entity, our management has determined that it is appropriate to apply the accounting prescribed by Topic 980, and, accordingly, the accompanying financial statements include the effects of the types of transactions described above that result from regulatory accounting requirements. In December 2017, the Tax Cuts and Jobs Act (Tax Reform) was enacted, which, among other things, reduced the federal corporate income tax rate from 35 percent to 21 percent. Rates charged to our customers currently permit the recovery of an income tax allowance that includes a deferred income tax component. As a result of the reduced income tax rate from Tax Reform, the WPZ Merger, as well as the collection of historical rates that reflected historical federal and state income tax rates, we expect we will be required to return amounts to certain customers through future rates and have accordingly established federal and state regulatory liabilities of $206.5 million and $12.1 million, respectively, as of December 2018. The timing and actual amount of such return will be subject to future negotiations regarding this matter and many other elements of cost-of-service rate proceedings, including other costs of providing service. Our regulatory asset associated with the effects of deferred taxes on equity funds used during construction was also impacted by Tax Reform and was reduced by $5.7 million in December 2017 through a charge to Miscellaneous other (income) expenses, net below Operating income. |
Use of Estimates | Use of Estimates The preparation of financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. Estimates and assumptions which, in the opinion of management, are significant to the underlying amounts included in the financial statements and for which it would be reasonably possible that future events or information could change those estimates include: 1) litigation-related contingencies; 2) environmental remediation obligations; 3) impairment assessments of long-lived assets; 4) depreciation; 5) asset retirement obligations; and 6) regulatory deferred tax. |
Revenue Recognition | Revenue Recognition (subsequent to adoption of ASC 606) Our customers are comprised of public utilities, municipalities, direct industrial users, electric power generators, and natural gas marketers and producers. A performance obligation is a promise in a contract to transfer a distinct good or service (or integrated package of goods or services) to the customer. A contract’s transaction price is allocated to each distinct performance obligation and recognized as revenue, when, or as, the performance obligation is satisfied. A performance obligation is distinct if the service is separately identifiable from other items in the integrated package of products or services and if a customer can benefit from it on its own or with other resources that are readily available to the customer. Service revenue contracts contain a series of distinct services, with the majority of our contracts having a single performance obligation that is satisfied over time as the customer simultaneously receives and consumes the benefits provided by our performance. Certain customers reimburse us for costs we incur associated with construction of property, plant, and equipment utilized in our operations. As a rate-regulated entity applying Topic 980, we follow FERC guidelines with respect to reimbursement of construction costs. FERC tariffs only allow for cost reimbursement and are non-negotiable in nature; thus, in our judgment, the construction activities do not represent an ongoing major and central operation of our gas pipelines business and are not within the scope of Accounting Standards Update (ASU) 2014-09, Revenues from Contracts with Customers (ASC 606). Accordingly, cost reimbursements are treated as a reduction to the cost of the constructed assets. Service Revenues We are subject to regulation by certain state and federal authorities, including the FERC, with revenue derived from both firm and interruptible transportation and storage contracts. Firm transportation and storage agreements provide for a fixed reservation charge based on the pipeline or storage capacity reserved, and a commodity charge based on the volume of natural gas scheduled, each at rates specified in our FERC tariffs or as negotiated with our customers, with contract terms that are generally long-term in nature. Most of our long-term contracts contain an evergreen provision, which allows the contracts to be extended beyond the specified contract term and until terminated generally by either us or the customer, but in certain cases unilaterally by the customer, with advance notice of termination ranging from one to five years. Interruptible transportation and storage agreements provide for a volumetric charge based on actual commodity transportation or storage utilized in the period in which those services are provided, and the contracts are generally limited to one month periods or less. Our performance obligations include the following: • Firm transportation or storage under firm transportation and storage contracts - an integrated package of services typically constituting a single performance obligation, which includes standing ready to provide such services and receiving, transporting or storing (as applicable), and redelivering commodities; • Interruptible transportation and storage under interruptible transportation and storage contracts - an integrated package of services typically constituting a single performance obligation once scheduled, which includes receiving, transporting or storing (as applicable), and redelivering commodities. In situations where, in our judgment, we consider the integrated package of services as a single performance obligation, which represents a majority of our contracts with customers, we do not consider there to be multiple performance obligations because the nature of the overall promise in the contract is to stand ready (with regard to firm transportation and storage contracts), receive, transport or store, and redeliver natural gas to the customer; therefore, revenue is recognized over time upon satisfaction of our daily stand ready performance obligation. We recognize revenues for reservation charges over the performance obligation period, which is the contract term, regardless of the volume of natural gas that is transported or stored. Revenues for commodity charges from both firm and interruptible transportation services and storage services are recognized based on volumes of natural gas scheduled for delivery at the agreed upon delivery point or based on volumes of natural gas scheduled for injection or withdrawn from the storage facility because they specifically relate to our efforts to provide these distinct services. Generally, reservation charges and commodity charges are recognized as revenue in the same period they are invoiced to our customers. As a result of the ratemaking process, certain amounts collected by us may be subject to refunds upon the issuance of final orders by the FERC in pending rate proceedings. We use judgment to record estimates of rate refund liabilities considering our and other third-party regulatory proceedings, advice of counsel, and other risks. At December 31, 2018 , we had no such rate refund liabilities. In the course of providing transportation services to customers, we may receive different quantities of natural gas from customers than the quantities delivered on behalf of those customers or consumed in fuel to operate our system. The resulting customer imbalances are typically settled through the receipt or delivery of gas in the future based on the timelines outlined in Northwest’s Tariff, whereas the over/under recovery of fuel is cleared up through Northwest’s semi-annual fuel tracker. Customer imbalances to be repaid or recovered in-kind are recorded as Exchange gas due from others or Exchange gas due to others in our Balance Sheet. The under recovery of fuel is recorded as a Regulatory Asset and the over recovery is recorded as a Regulatory Liability. These imbalances are valued at the average of the spot market rates at the Canadian border and the Rocky Mountain market as published in the SNL Financial "Bidweek Index - Spot Rates." Revenue Recognition (prior to the adoption of ASC 606) Our revenues are primarily from services pursuant to long term firm transportation and storage agreements. These agreements provide for a reservation charge based on the volume of contracted capacity and a volumetric charge based on the volume of gas delivered, both at rates specified in our FERC tariffs. We recognize revenues for reservation charges ratably over the contract period regardless of the volume of natural gas that is transported or stored. Revenues for volumetric charges, from both firm and interruptible transportation services and storage injection and withdrawal services, are recognized based on volumes of natural gas scheduled for delivery at the agreed upon delivery point or based on volumes of natural gas scheduled for injection or withdrawal from the storage facility. In the course of providing transportation services to customers, we may receive different quantities of natural gas from customers than the quantities delivered on behalf of those customers or consumed in fuel to operate our system. The resulting customer imbalances are typically settled through the receipt or delivery of gas in the future based on the timelines outlined in Northwest’s Tariff, whereas the over/under recovery of fuel is cleared up through Northwest’s semi-annual fuel tracker. Customer imbalances to be repaid or recovered in-kind are recorded as Exchange gas due from others or Exchange gas due to others in our Balance Sheet. The under recovery of fuel is recorded as a Regulatory Asset and the over recovery is recorded as a Regulatory Liability. These imbalances are valued at the average of the spot market rates at the Canadian border and the Rocky Mountain market as published in the SNL Financial "Bidweek Index - Spot Rates." As a result of the ratemaking process, certain revenues collected by us may be subject to refunds upon the issuance of final orders by the FERC in pending rate proceedings. We record estimates of rate refund liabilities considering our and third-party regulatory proceedings, advice of counsel and other risks. |
Environmental Matters | Environmental Matters We are subject to federal, state, and local environmental laws and regulations. Environmental expenditures are expensed or capitalized depending on their economic benefit and potential for rate recovery. We believe that expenditures required to meet applicable environmental laws and regulations are prudently incurred in the ordinary course of business and such expenditures would be permitted to be recovered through rates. |
Property, Plant, and Equipment | Property, Plant, and Equipment Property, plant and equipment (plant), consisting principally of natural gas transmission facilities, is recorded at original cost. The FERC identifies installation, construction and replacement costs that are to be capitalized and included in our asset base for recovery in rates. Routine maintenance, repairs, and renewal costs are charged to income as incurred. Gains or losses from the ordinary sale or retirement of plant are charged or credited to accumulated depreciation; certain other gains or losses are recorded in operating income. We provide for depreciation under the composite (group) method at straight-line FERC prescribed rates that are applied to the cost of the group for transmission and storage facilities. Under this method, assets with similar lives and characteristics are grouped and depreciated as one asset. Included in our depreciation rates is a negative salvage component (net cost of removal) that we currently collect in rates. Our depreciation rates are subject to change each time we file a general rate case with the FERC. Depreciation rates used for major regulated gas plant facilities at December 31, 2018 , 2017 , and 2016 are as follows: Category of Property Storage Facilities 1.60 % — 2.76% Transmission Facilities 2.80 % — 6.97% The incrementally priced Evergreen Expansion Project, which was an expansion of our pipeline system, was placed in service on October 1, 2003. The levelized rate design of this project creates a consistent revenue stream over the related 25-year and 15-year customer contract terms. The related levelized depreciation is lower than book depreciation in the early years and higher than book depreciation in the later years of the contract terms. The depreciation component of the levelized incremental rates will equal the accumulated book depreciation by the end of the primary contract terms. The FERC has approved the accounting for the differences between book depreciation and the Evergreen Expansion Project’s levelized depreciation as a regulatory asset. The levelized period for the 15-year contracts ended September 30, 2018. We recorded regulatory debits totaling $2.3 million in 2018 , $4.9 million in 2017 , and $3.5 million in 2016 in the accompanying Statement of Comprehensive Income (Loss). These debits relate primarily to the levelized depreciation adjustment for the Evergreen Project discussed above. We record a liability and increase the basis in the underlying asset for the present value of each expected future asset retirement obligation (ARO) at the time the liability is initially incurred, typically when the asset is acquired or constructed. Measurement of AROs includes, as a component of future expected costs, an estimate of the price that a third party would demand, and could expect to receive, for bearing the uncertainties inherent in the obligations, sometimes referred to as market-risk premium. We measure changes in the liability due to passage of time by applying an interest method of allocation. This amount is recognized as an increase in the carrying amount of the liability and is offset by a regulatory asset. The gross regulatory asset balances associated with ARO as of December 31, 2018 and 2017 were $86.4 million and $82.2 million, respectively. The regulatory asset is expected to be fully recovered through the net negative salvage component of depreciation included in our rates; as such, the negative salvage component of accumulated depreciation was ($86.4) million and ($82.2) million at December 31, 2018 and 2017 , respectively, and has been reclassified and netted against the amount of the ARO regulatory asset. |
Impairment of Long-Lived Assets | Impairment of Long-Lived Assets We evaluate long-lived assets for impairment when events or changes in circumstances indicate, in our management’s judgment, that the carrying value of such assets may not be recoverable. When such a determination has been made, our management’s estimate of undiscounted future cash flows attributable to the assets is compared to the carrying value of the assets to determine whether an impairment has occurred. If an impairment of the carrying value has occurred, the amount of the impairment recognized in the financial statements is determined by estimating the fair value of the assets and recording a loss for the amount that the carrying value exceeds the estimated fair value. Judgments and assumptions are inherent in our management’s estimate of undiscounted future cash flows used to determine recoverability of an asset and the estimate of an asset’s fair value used to calculate the amount of impairment to recognize. The use of alternate judgments and/or assumptions could result in the recognition of different levels of impairment charges in the financial statements. |
Allowance for Funds Used During Construction | Allowance for Funds Used During Construction Allowance for funds used during construction (AFUDC) represents the estimated cost of borrowed and equity funds applicable to utility plant in process of construction and is included as a cost of property, plant and equipment because it constitutes an actual cost of construction under established regulatory practices. The FERC has prescribed a formula to be used in computing separate allowances for borrowed and equity AFUDC. The allowance for borrowed funds used during construction was $0.5 million for 2018 , $0.3 million for 2017 , and $0.4 million for 2016 . The allowance for equity funds was $1.7 million, $1.1 million, and $1.0 million for 2018 , 2017 , and 2016 , respectively. Both are reflected in Other (Income) and Other Expenses . |
Income Taxes | Income Taxes We are a natural gas company organized as a pass-through entity and our taxable income or loss is consolidated on the federal income tax return of our parent, Williams. We generally are treated as a pass-through entity for state and local income tax purposes, and those taxes are generally borne on a consolidated basis by Williams. Net income for financial statement purposes may differ significantly from taxable income of Williams as a result of differences between the tax basis and financial reporting basis of assets and liabilities. |
Accounts Receivable and Allowance for Doubtful Receivables | Accounts Receivable and Allowance for Doubtful Receivables Accounts receivable are stated at the historical carrying amount net of reserves or write-offs. We do not offer extended payment terms and typically receive payment within one month. We consider receivables past due if full payment is not received by the contractual due date. Our credit risk exposure in the event of nonperformance by the other parties is limited to the face value of the receivables. We perform ongoing credit evaluations of our customers’ financial condition and require collateral from our customers, if necessary. Due to our customer base, we have not historically experienced recurring credit losses in connection with our receivables. Receivables determined to be uncollectible are reserved or written off in the period of determination. |
Materials and Supplies Inventory | Materials and Supplies Inventory All inventories are stated at cost. We determine the cost of the inventories using the average cost method. We perform an annual review of materials and supplies inventories, including an analysis of parts that may no longer be useful due to planned replacements of compressor engines and other components on our system. Based on this assessment, we record a reserve for the value of the inventory which can no longer be used for maintenance and repairs on our pipeline. There was a minimal reserve at December 31, 2018 and 2017 . |
Deferred Charges | Deferred Charges We amortize deferred charges over varying periods consistent with the FERC approved accounting treatment and recovery for such deferred items. Unamortized debt expense, debt discount and losses on reacquired long-term debt are amortized by the bonds outstanding method over the related debt repayment periods. |
Contingent Liabilities | Contingent Liabilities We record liabilities for estimated loss contingencies, including environmental matters, when we assess that a loss is probable and the amount of the loss can be reasonably estimated. These liabilities are calculated based upon our assumptions and estimates with respect to the likelihood or amount of loss and upon advice of legal counsel, engineers, or other third parties regarding the probable outcomes of the matters. These calculations are made without consideration of any potential recovery from third-parties. We recognize insurance recoveries or reimbursements from others when realizable. Revisions to these liabilities are generally reflected in income when new or different facts or information become known or circumstances change that affect the previous assumptions or estimates. |
Pension and Other Postretirement Benefits | Pension and Other Postretirement Benefits We do not have employees. Certain of the costs charged to us by Williams associated with employees who directly support us include costs related to Williams’ pension and other postretirement benefit plans. (See Note 6 for further discussion.) Although the underlying benefit plans of Williams are single-employer plans, we follow multiemployer plan accounting whereby the amount charged to us, and thus paid by us, is based on our share of net periodic benefit cost. |
Cash Equivalents | Cash Flows from Operating Activities and Cash Equivalents We use the indirect method to report cash flows from operating activities, which requires adjustments to net income to reconcile to net cash flows provided by operating activities. We include short-term, highly-liquid investments that have an original maturity of three months or less as cash equivalents. |
Financial Instruments (Policies
Financial Instruments (Policies) | 12 Months Ended |
Dec. 31, 2018 | |
Fair Value Disclosures [Abstract] | |
Fair value of financial instruments | Fair Value of Financial Instruments The following methods and assumptions were used to estimate the fair value of each class of financial instruments for which it is practicable to estimate that value: Cash and advances to affiliate —The carrying amounts approximate fair value, because of the short-term nature of these instruments. Long-term debt – The disclosed fair value of our long-term debt, which we consider as a level 2 measurement, is determined by a market approach using broker quoted indicative period-end bond prices. The quoted prices are based on observable transactions in less active markets for our debt or similar instruments. The carrying amount and estimated fair value of our long-term debt, including current maturities, were $576.2 million and $577.1 million , respectively, at December 31, 2018 , and $581.6 million and $606.8 million , respectively, at December 31, 2017 . |
Summary of Significant Accoun_3
Summary of Significant Accounting Policies (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
Depreciation rates | We provide for depreciation under the composite (group) method at straight-line FERC prescribed rates that are applied to the cost of the group for transmission and storage facilities. Under this method, assets with similar lives and characteristics are grouped and depreciated as one asset. Included in our depreciation rates is a negative salvage component (net cost of removal) that we currently collect in rates. Our depreciation rates are subject to change each time we file a general rate case with the FERC. Depreciation rates used for major regulated gas plant facilities at December 31, 2018 , 2017 , and 2016 are as follows: Category of Property Storage Facilities 1.60 % — 2.76% Transmission Facilities 2.80 % — 6.97% |
Debt, Financing Arrangements,_2
Debt, Financing Arrangements, and Leases (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Debt Disclosure [Abstract] | |
Long-term debt | Long-term debt, presented net of unamortized discount and unamortized debt issuance costs, consists of the following: December 31, 2018 2017 (Thousands of Dollars) 6.05% senior unsecured notes due 2018 $ — $ 250,000 7.125% unsecured debentures due 2025 85,000 85,000 4.0% unsecured debentures due 2027 500,000 250,000 Debt issuance costs (4,507 ) (2,415 ) Unamortized debt discount (4,325 ) (963 ) Total long-term debt, including current portion 576,168 581,622 Long-term debt due within one year — 249,874 Total long-term debt less current portion $ 576,168 $ 331,748 |
Future Minimum lease payments | Following are the estimated future minimum annual rental payments required under operating leases, which have initial or remaining noncancelable lease terms in excess of one year: (Thousands of Dollars) 2019 $ 1,942 2020 1,968 2021 1,920 2022 1,909 2023 1,832 Thereafter 11,508 Total $ 21,079 |
Transactions with Major Custo_2
Transactions with Major Customers and Affiliates (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Transactions with Major Customers and Affiliates [Abstract] | |
Schedule of revenue by major customers | During the periods presented, more than 10 percent of our operating revenues were generated from each of the following customers: Years Ended December 31, 2018 2017 2016 (Thousands of Dollars) Puget Sound Energy, Inc. $ 115,238 $ 120,226 $ 120,351 Northwest Natural Gas Company 49,126 51,743 49,895 Cascade Natural Gas Corporation 46,164 48,071 47,951 |
Asset Retirement Obligations (T
Asset Retirement Obligations (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Asset Retirement Obligation Disclosure [Abstract] | |
Schedule of change in asset retirement obligation | During 2018 and 2017 , our overall asset retirement obligation changed as follows (in thousands): 2018 2017 Beginning balance $ 67,100 $ 60,762 Accretion 4,359 3,968 New obligations — 149 Changes in estimates of existing obligations (1) (2,095 ) 2,510 Property dispositions/obligations settled (14 ) (289 ) Ending balance $ 69,350 $ 67,100 (1) Changes in estimates of existing obligations are primarily due to the annual review process, which considers various factors including inflation rates, current estimates for removal costs, the estimated remaining life of assets, and discount rates. |
Regulatory Assets and Liabili_2
Regulatory Assets and Liabilities (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Regulatory Assets and Liabilities Disclosure [Abstract] | |
Schedule of Regulatory Assets and Liabilities [Table Text Block] | Our regulatory assets and liabilities result from our application of the provisions of ASC Topic 980 and are reflected on our Balance Sheet. Current regulatory assets are included in Prepayments and other . Current regulatory liabilities are included in Exchange gas offset . These balances are presented on our Balance Sheet on a gross basis and are recoverable or refundable over various periods. Below are the details of our regulatory assets and liabilities as of December 31, 2018 and 2017 : 2018 2017 (Thousands of Dollars) Current regulatory assets: Levelized depreciation $ 414 $ 4,707 Fuel Recovery 6,619 — Total current regulatory assets 7,033 4,707 Noncurrent regulatory assets: Grossed-up deferred taxes on equity funds used during construction 5,883 6,598 Levelized depreciation 18,109 16,149 Total noncurrent regulatory assets 23,992 22,747 Total regulatory assets $ 31,025 $ 27,454 Current regulatory liabilities: Fuel recovery $ — $ 1,539 Noncurrent regulatory liabilities: Postretirement benefits 36,154 34,089 Deferred federal taxes-liability 206,527 206,547 Deferred state taxes - liability 12,120 — Customer tax refund 24,094 — Asset retirement obligations, net 11,535 5,868 Total noncurrent regulatory liabilities 290,430 246,504 Total regulatory liabilities $ 290,430 $ 248,043 |
Revenue Recognition (Tables)
Revenue Recognition (Tables) | 12 Months Ended |
Dec. 31, 2018 | |
Revenue Recognition [Abstract] | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block] | The following table presents the transaction price allocated to the remaining performance obligations under certain contracts as of December 31, 2018 . These primarily include reservation charges on contracted capacity on our firm transportation and storage contracts with customers. Amounts from certain contracts included in the table below, which are subject to the periodic review and approval by the FERC, reflect the rates for such services in our current FERC tariffs for the life of the related contracts; however, these rates may change based on future rate cases or settlements approved by the FERC and the amount and timing of these changes is not currently known. As a practical expedient permitted by ASC 606, this table excludes the variable consideration component for commodity charges that will be recognized in future periods. As noted above, certain of our contracts contain evergreen provisions for periods beyond the initial term of the contract. The remaining performance obligations as of December 31, 2018 , does not consider potential future performance obligations for which the renewal has not been exercised. The table below also does not include contracts with customers for which the underlying facilities have not received FERC authorization to be placed into service. (Thousands) 2019 $ 427,705 2020 404,899 2021 378,288 2022 372,446 2023 329,338 Thereafter 1,832,771 Total $ 3,745,447 |
Summary of Significant Accoun_4
Summary of Significant Accounting Policies (Details) | 12 Months Ended | ||
Dec. 31, 2018USD ($)employee | Dec. 31, 2017USD ($) | Dec. 31, 2016USD ($) | |
Subsidiary of Limited Liability Company or Limited Partnership [Line Items] | |||
Entity number of employees | employee | 0 | ||
Regulatory charge resulting from tax rate change | $ 35,680,000 | $ 206,547,000 | $ 0 |
Revenue Recognition [Abstract] | |||
Reserve for rate refund, Current | 0 | ||
Reserve for rate refund, Noncurrent | 0 | ||
Public Utility, Property, Plant and Equipment [Line Items] | |||
Regulatory debits | 2,334,000 | 4,857,000 | 3,510,000 |
Regulatory assets | 23,992,000 | 22,747,000 | |
Capitalized Interest Costs, Including Allowance for Funds Used During Construction [Abstract] | |||
Allowance for funds used during construction, debt | 500,000 | 300,000 | 400,000 |
Allowance for funds used during construction, equity | 1,703,000 | 1,104,000 | 953,000 |
Interest Payments [Abstract] | |||
Cash payments for interest, net of interest capitalized | 25,400,000 | 31,900,000 | 38,500,000 |
State Tax [Member] | |||
Subsidiary of Limited Liability Company or Limited Partnership [Line Items] | |||
Regulatory charge resulting from tax rate change | 12,100,000 | ||
Levelized depreciation [Member] | |||
Public Utility, Property, Plant and Equipment [Line Items] | |||
Regulatory debits | 2,300,000 | 4,900,000 | $ 3,500,000 |
Regulatory assets | 18,109,000 | 16,149,000 | |
Asset retirement obligation [Member] | |||
Public Utility, Property, Plant and Equipment [Line Items] | |||
Regulatory assets | 86,400,000 | 82,200,000 | |
Negative salvage [Member] | |||
Public Utility, Property, Plant and Equipment [Line Items] | |||
Regulatory assets | $ 86,400,000 | $ 82,200,000 | |
Minimum [Member] | |||
Subsidiary of Limited Liability Company or Limited Partnership [Line Items] | |||
Effective Income Tax Rate Reconciliation, Deduction, Percent | 21.00% | ||
Maximum [Member] | |||
Subsidiary of Limited Liability Company or Limited Partnership [Line Items] | |||
Effective Income Tax Rate Reconciliation, Deduction, Percent | 35.00% | ||
Maximum [Member] | Accounting Standards Update 2016-02 [Member] | |||
Subsidiary of Limited Liability Company or Limited Partnership [Line Items] | |||
Operating Lease Liability Percentage Of Total Liabilities | 3.00% | ||
Operating Lease Right Of Use Asset Percentage Of Total Assets | 3.00% | ||
Storage Facilities [Member] | Minimum [Member] | |||
Public Utility, Property, Plant and Equipment [Line Items] | |||
Depreciaton rates | 1.60% | 1.60% | 1.60% |
Storage Facilities [Member] | Maximum [Member] | |||
Public Utility, Property, Plant and Equipment [Line Items] | |||
Depreciaton rates | 2.76% | 2.76% | 2.76% |
Transmission Facilities [Member] | Minimum [Member] | |||
Public Utility, Property, Plant and Equipment [Line Items] | |||
Depreciaton rates | 2.80% | 2.80% | 2.80% |
Transmission Facilities [Member] | Maximum [Member] | |||
Public Utility, Property, Plant and Equipment [Line Items] | |||
Depreciaton rates | 6.97% | 6.97% | 6.97% |
Other Nonoperating Income (Expense) [Member] | |||
Subsidiary of Limited Liability Company or Limited Partnership [Line Items] | |||
Regulatory charge resulting from tax rate change | $ 5,700,000 | ||
Operating Expense [Member] | |||
Subsidiary of Limited Liability Company or Limited Partnership [Line Items] | |||
Regulatory charge resulting from tax rate change | $ 206,547,000 |
Rate and Regulatory Matters (De
Rate and Regulatory Matters (Details) $ in Thousands | Oct. 01, 2018$ / dekatherm | Jan. 01, 2018$ / dekatherm | Jan. 23, 2017USD ($) | Dec. 31, 2018USD ($) | Dec. 31, 2017USD ($) |
Public Utilities, General Disclosures [Line Items] | |||||
Annual Cost of Service | $ 440,000 | ||||
Regulatory Liabilities | $ 290,430 | $ 248,043 | |||
Phase 1 Demand Rate per Dth Pending | |||||
Public Utilities, General Disclosures [Line Items] | |||||
Demand Rate | $ / dekatherm | 0.39294 | ||||
Phase 1 Commodity Rate Pending | |||||
Public Utilities, General Disclosures [Line Items] | |||||
Commodity Rate | $ / dekatherm | 0.00832 | ||||
Phase 2 Demand Rate per Dth Pending | |||||
Public Utilities, General Disclosures [Line Items] | |||||
Demand Rate | $ / dekatherm | 0.39033 | ||||
Phase 2 Commodity Rate Pending | |||||
Public Utilities, General Disclosures [Line Items] | |||||
Commodity Rate | $ / dekatherm | 0.00832 | ||||
Deferred Income Tax Charge [Member] | |||||
Public Utilities, General Disclosures [Line Items] | |||||
Regulatory Liabilities | $ 23,600 | 0 | |||
Regulatory Liability, Amortization Period | 5 years | ||||
Accrued Interest on Deferred Regulatory Tax Liability [Member] | |||||
Public Utilities, General Disclosures [Line Items] | |||||
Regulatory Liabilities | $ 500 | ||||
State Tax [Member] | |||||
Public Utilities, General Disclosures [Line Items] | |||||
Regulatory Liabilities | $ 12,100 | $ 0 |
Contingent Liabilities and Co_2
Contingent Liabilities and Commitments (Details) - USD ($) $ in Millions | Dec. 31, 2018 | Dec. 31, 2017 |
Environmental Matters | ||
Environmental assessment and remediation costs, undiscounted | $ 2 | |
Accrued environmental liabilities | 2 | $ 3 |
Accrued Environmental Loss Contingencies, Current | 1.3 | 1.3 |
Accrued Environmental Loss Contingencies, Noncurrent | $ 0.7 | $ 1.7 |
Debt, Financing Arrangements,_3
Debt, Financing Arrangements, and Leases (Details) - USD ($) | Apr. 15, 2017 | Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | Aug. 24, 2018 | Jul. 13, 2018 | May 02, 2018 | Apr. 03, 2017 | Oct. 01, 2009 |
Debt Instrument [Line Items] | |||||||||
Debt issuance costs | $ 4,507,000 | $ 2,415,000 | |||||||
Debt Instrument, Unamortized Discount, Noncurrent | 4,325,000 | 963,000 | |||||||
Long-term debt due within one year | 0 | 249,874,000 | |||||||
Total long-term debt less current portion | 576,168,000 | 331,748,000 | |||||||
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract] | |||||||||
2,019 | 1,942,000 | ||||||||
2,020 | 1,968,000 | ||||||||
2,021 | 1,920,000 | ||||||||
2,022 | 1,909,000 | ||||||||
2,023 | 1,832,000 | ||||||||
Thereafter | 11,508,000 | ||||||||
Operating Leases, Future Minimum Payments Due | 21,079,000 | ||||||||
Lessee, Operating Lease, Term of Contract | 10 years | ||||||||
Lessee, Operating Lease, Renewal Term | 10 years | ||||||||
Operating Leases, Rent Expense | $ 2,800,000 | 3,500,000 | $ 2,700,000 | ||||||
4% Senior Unsecured Notes Due 2027 [Member] | |||||||||
Debt Instrument [Line Items] | |||||||||
Issuance of debt | $ 250,000,000 | ||||||||
Debt Instrument, Interest Rate, Stated Percentage | 4.00% | ||||||||
6.05% Senior Unsecured Notes due 2018 [Member] | |||||||||
Debt Instrument [Line Items] | |||||||||
Long-term Debt | $ 0 | 250,000,000 | |||||||
7.125 percent unsecured debentures due 2025 [Member] | |||||||||
Debt Instrument [Line Items] | |||||||||
Long-term Debt | 85,000,000 | 85,000,000 | |||||||
4.0% unsecured debentures due 2027 [Member] | |||||||||
Debt Instrument [Line Items] | |||||||||
Long-term Debt | 500,000,000 | $ 250,000,000 | |||||||
Issuance of debt | $ 250,000,000 | ||||||||
5.95 percent senior unsecured notes due 2017 [Member] | |||||||||
Debt Instrument [Line Items] | |||||||||
Debt Instrument, Interest Rate, Stated Percentage | 5.95% | ||||||||
Extinguishment of Debt, Amount | $ 185,000,000,000 | ||||||||
Line of Credit [Member] | |||||||||
Line of Credit Facility [Line Items] | |||||||||
Line of Credit Facility, Maximum Borrowing Capacity | $ 500,000,000 | ||||||||
Line of Credit [Member] | Williams Companies Inc [Member] | |||||||||
Line of Credit Facility [Line Items] | |||||||||
Line of Credit Facility, Maximum Borrowing Capacity | 4,500,000,000 | ||||||||
Additional Amount By Which Credit Facility Can Be Increased | 500,000,000 | ||||||||
Long-term Line of Credit | 160,000,000 | ||||||||
Swing Line Loan | Williams Companies Inc [Member] | |||||||||
Line of Credit Facility [Line Items] | |||||||||
Line of Credit Facility, Maximum Borrowing Capacity | 200,000,000 | ||||||||
Commercial Paper [Member] | Williams Companies Inc [Member] | |||||||||
Line of Credit Facility [Line Items] | |||||||||
Line of Credit Facility, Maximum Borrowing Capacity | 4,000,000,000 | ||||||||
Commercial Paper | 0 | ||||||||
Letter of Credit [Member] | |||||||||
Line of Credit Facility [Line Items] | |||||||||
Line of Credit Facility, Maximum Borrowing Capacity | 500,000,000 | ||||||||
Letters of Credit Outstanding, Amount | $ 0 | ||||||||
Letter of Credit [Member] | Williams Companies Inc [Member] | |||||||||
Line of Credit Facility [Line Items] | |||||||||
Line of Credit Facility, Maximum Borrowing Capacity | $ 1,000,000,000 |
Employee Benefit Plans (Details
Employee Benefit Plans (Details) - USD ($) $ in Thousands | 12 Months Ended | ||
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016 | |
Defined Benefit Plan Disclosure [Line Items] | |||
Regulatory liabilities | $ 290,430 | $ 246,504 | |
Salary and Wage, Excluding Cost of Good and Service Sold [Abstract] | |||
Stock-based compensation expense | 1,800 | 1,900 | $ 1,400 |
Other Postretirement Benefit Costs | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Regulatory liabilities | 36,200 | 34,100 | |
Williams Companies Inc [Member] | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Pension cost | 3,900 | 5,200 | 2,300 |
Defined contribution plan matching contributions expense | 1,900 | 2,100 | 2,200 |
Williams Companies Inc [Member] | Retiree health care and life insurance benefits [Member] | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Regulatory liabilities | 2,100 | 3,500 | $ 3,800 |
Williams Companies Inc [Member] | Pension Plan [Member] | Directly charged [Member] | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Defined Benefit Plan, Plan Assets, Payment for Settlement | 1,300 | 3,000 | |
Williams Companies Inc [Member] | Pension Plan [Member] | Allocated corporate expenses [Member] | |||
Defined Benefit Plan Disclosure [Line Items] | |||
Defined Benefit Plan, Plan Assets, Payment for Settlement | $ 700 | $ 1,100 |
Financial Instruments (Details)
Financial Instruments (Details) - USD ($) $ in Thousands | Dec. 31, 2018 | Dec. 31, 2017 |
Reported Value Measurement [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Long-term Debt, Gross | $ 576,168 | $ 581,622 |
Estimate of fair value [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Long-term Debt, Fair Value | $ 577,100 | $ 606,800 |
Transactions with Major Custo_3
Transactions with Major Customers and Affiliates (Details) $ in Thousands | 1 Months Ended | 12 Months Ended | ||
Jan. 31, 2019USD ($) | Dec. 31, 2018USD ($)employee | Dec. 31, 2017USD ($) | Dec. 31, 2016USD ($) | |
Related Party Transaction [Line Items] | ||||
Advances to affiliate | $ 180,400 | $ 137,666 | ||
Related party transaction, rate | 2.24% | |||
Entity number of employees | employee | 0 | |||
Related party transaction, expenses from transactions with related party | $ 92,700 | 96,500 | $ 92,800 | |
Severance Costs | 2,400 | |||
Cash distributions to parent | 174,000 | 186,000 | 174,000 | |
Williams Companies Inc [Member] | ||||
Related Party Transaction [Line Items] | ||||
Advances to affiliate | 180,400 | 137,666 | ||
Subsequent Event [Member] | ||||
Related Party Transaction [Line Items] | ||||
Cash distributions to parent | $ 21,000 | |||
Puget Sound Energy, Inc. [Member] | ||||
Revenue, Major Customer [Line Items] | ||||
Operating revenues | 115,238 | 120,226 | 120,351 | |
Northwest Natural Gas Company [Member] | ||||
Revenue, Major Customer [Line Items] | ||||
Operating revenues | 49,126 | 51,743 | 49,895 | |
Cascade Natural Gas Corporation [Member] | ||||
Revenue, Major Customer [Line Items] | ||||
Operating revenues | $ 46,164 | $ 48,071 | $ 47,951 |
Asset Retirement Obligations (D
Asset Retirement Obligations (Details) - USD ($) $ in Thousands | 12 Months Ended | |
Dec. 31, 2018 | Dec. 31, 2017 | |
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] | ||
Beginning balance | $ 67,100 | $ 60,762 |
Accretion | 4,359 | 3,968 |
New obligations | 0 | 149 |
Changes in estimates of existing obligations (1) | (2,095) | 2,510 |
Property dispositions/obligations settled | (14) | (289) |
Ending balance | $ 69,350 | $ 67,100 |
Regulatory Assets and Liabili_3
Regulatory Assets and Liabilities (Details) - USD ($) $ in Thousands | Dec. 31, 2018 | Dec. 31, 2017 |
Regulatory Assets [Line Items] | ||
Current regulatory assets | $ 7,033 | $ 4,707 |
Noncurrent regulatory assets | 23,992 | 22,747 |
Total regulatory assets | 31,025 | 27,454 |
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 290,430 | 246,504 |
Total regulatory liabilities | 290,430 | 248,043 |
Fuel recovery [Member] | ||
Regulatory Liabilities [Line Items] | ||
Current regulatory liabilities | 0 | 1,539 |
Postretirement benefits [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 36,154 | 34,089 |
Deferred federal taxes-liability | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 206,527 | 206,547 |
Total regulatory liabilities | 23,600 | 0 |
Deferred state taxes - liability | ||
Regulatory Liabilities [Line Items] | ||
Total regulatory liabilities | 12,100 | 0 |
Customer tax refund [Domain] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 24,094 | |
Asset retirement obligations, net [Member] | ||
Regulatory Liabilities [Line Items] | ||
Regulatory liabilities | 11,535 | 5,868 |
Fuel recovery [Member] | ||
Regulatory Assets [Line Items] | ||
Current regulatory assets | 6,619 | 0 |
Levelized depreciation [Member] | ||
Regulatory Assets [Line Items] | ||
Current regulatory assets | 414 | 4,707 |
Noncurrent regulatory assets | 18,109 | 16,149 |
Deferred taxes on equity funds used during construction [Member] | ||
Regulatory Assets [Line Items] | ||
Noncurrent regulatory assets | $ 5,883 | $ 6,598 |
Revenue Recognition (Details)
Revenue Recognition (Details) | Dec. 31, 2018USD ($) |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01 | Remaining Performance Obligations [Member] | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, Remaining Performance Obligation, Amount | $ 427,705,000 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01 | Remaining Performance Obligations [Member] | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, Remaining Performance Obligation, Amount | $ 404,899,000 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | Remaining Performance Obligations [Member] | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, Remaining Performance Obligation, Amount | $ 378,288,000 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | Remaining Performance Obligations [Member] | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, Remaining Performance Obligation, Amount | $ 372,446,000 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, Remaining Performance Obligation, Amount | $ 11,000,000 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | Remaining Performance Obligations [Member] | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, Remaining Performance Obligation, Amount | $ 329,338,000 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period | 1 year |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, Remaining Performance Obligation, Amount | $ 549,000,000 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | Remaining Performance Obligations [Member] | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, Remaining Performance Obligation, Amount | $ 3,745,447,000 |