Document and Entity Information
Document and Entity Information - shares | 3 Months Ended | |
Mar. 31, 2021 | May 03, 2021 | |
Document and Entity Information [Abstract] | ||
Document Type | 10-Q | |
Document Quarterly Report | true | |
Document period end date | Mar. 31, 2021 | |
Document Transition Report | false | |
Entity File Number | 1-7414 | |
Entity registrant name | NORTHWEST PIPELINE LLC | |
Entity Incorporation, State or Country Code | DE | |
Entity Tax Identification Number | 26-1157701 | |
Entity Address, Address Line One | 295 Chipeta Way | |
Entity Address, City or Town | Salt Lake City | |
Entity Address, State or Province | UT | |
Entity Address, Postal Zip Code | 84108 | |
City Area Code | 801 | |
Local Phone Number | 583-8800 | |
Entity Current Reporting Status | Yes | |
Entity Interactive Data Current | Yes | |
Entity filer category | Non-accelerated Filer | |
Entity Small Business | false | |
Entity Emerging Growth Company | false | |
Entity Shell Company | false | |
Entity central index key | 0000110019 | |
Amendment flag | false | |
Document fiscal year focus | 2021 | |
Document fiscal period focus | Q1 | |
Current fiscal year end date | --12-31 | |
Entity common stock, shares outstanding | 0 |
Statement of Net Income (Unaudi
Statement of Net Income (Unaudited) - USD ($) $ in Thousands | 3 Months Ended | |
Mar. 31, 2021 | Mar. 31, 2020 | |
OPERATING REVENUES: | ||
Natural gas transportation | $ 109,277 | $ 112,021 |
Natural gas storage | 3,670 | 3,346 |
Other | (53) | (21) |
Total operating revenues | 112,894 | 115,346 |
OPERATING EXPENSES: | ||
General and administrative | 11,670 | 12,699 |
Operation and maintenance | 16,646 | 15,499 |
Depreciation and amortization | 28,068 | 28,060 |
Regulatory debits | 348 | 291 |
Taxes, other than income taxes | 4,216 | 4,120 |
Regulatory charges resulting from tax rate changes | 5,814 | 5,814 |
Other (income) expenses, net | (31) | (2) |
Total operating expenses | 66,731 | 66,481 |
OPERATING INCOME | 46,163 | 48,865 |
OTHER (INCOME) AND OTHER EXPENSES: | ||
Interest expense | 7,361 | 7,451 |
Allowance for equity and borrowed funds used during construction (AFUDC) | (265) | (298) |
Miscellaneous other (income) expenses, net | (161) | (1,092) |
Total other (income) and other expenses | 6,935 | 6,061 |
NET INCOME | $ 39,228 | $ 42,804 |
Balance Sheet (Unaudited)
Balance Sheet (Unaudited) - USD ($) $ in Thousands | Mar. 31, 2021 | Dec. 31, 2020 |
CURRENT ASSETS: | ||
Cash | $ 0 | $ 0 |
Receivables: | ||
Trade | 37,283 | 37,365 |
Affiliated companies | 60 | 51 |
Advances to affiliate | 265,719 | 247,869 |
Other | 765 | 840 |
Materials and supplies | 9,849 | 9,807 |
Exchange gas due from others | 3,276 | 4,466 |
Prepayments and other | 3,396 | 4,078 |
Total current assets | 320,348 | 304,476 |
PROPERTY, PLANT AND EQUIPMENT | 3,657,039 | 3,653,792 |
Less-Accumulated depreciation and amortization | 1,785,462 | 1,761,229 |
Total property, plant and equipment, net | 1,871,577 | 1,892,563 |
OTHER ASSETS: | ||
Deferred charges | 4,808 | 3,775 |
Regulatory assets | 10,452 | 10,692 |
Right-of-use assets | 19,374 | 20,022 |
Total other assets | 34,634 | 34,489 |
Total assets | 2,226,559 | 2,231,528 |
Payables: | ||
Trade | 5,636 | 16,157 |
Affiliated companies | 7,977 | 4,110 |
Accrued liabilities: | ||
Taxes, other than income taxes | 14,613 | 10,905 |
Interest | 12,019 | 5,505 |
Exchange gas due to others | 1,830 | 4,557 |
Customer advances | 1,781 | 539 |
Other | 6,377 | 6,786 |
Total current liabilities | 50,233 | 48,559 |
LONG-TERM DEBT | 578,267 | 578,018 |
OTHER NONCURRENT LIABILITIES: | ||
Asset retirement obligations | 97,129 | 95,777 |
Regulatory liabilities | 363,771 | 355,725 |
Lease liability | 8,158 | 8,341 |
Other | 4,378 | 4,713 |
Total other noncurrent liabilities | 473,436 | 464,556 |
CONTINGENT LIABILITIES AND COMMITMENTS (Note 3) | ||
MEMBER'S EQUITY: | ||
Member's capital | 1,073,892 | 1,073,892 |
Retained earnings | 50,731 | 66,503 |
Total member's equity | 1,124,623 | 1,140,395 |
Total liabilities and member's equity | $ 2,226,559 | $ 2,231,528 |
Statement of Member's Equity (U
Statement of Member's Equity (Unaudited) - USD ($) $ in Thousands | Total | MEMBER'S CAPITAL | RETAINED EARNINGS |
Balance at beginning and end of period at Dec. 31, 2019 | $ 1,073,892 | $ 79,417 | |
Net income | $ 42,804 | 42,804 | |
Cash distributions to parent | (45,000) | (45,000) | |
Balance at end of period at Mar. 31, 2020 | 1,151,113 | 77,221 | |
Balance at beginning and end of period at Dec. 31, 2020 | 1,140,395 | $ 1,073,892 | 66,503 |
Net income | 39,228 | 39,228 | |
Cash distributions to parent | (55,000) | (55,000) | |
Balance at end of period at Mar. 31, 2021 | $ 1,124,623 | $ 50,731 |
Statement of Cash Flows (Unaudi
Statement of Cash Flows (Unaudited) - USD ($) $ in Thousands | 3 Months Ended | |
Mar. 31, 2021 | Mar. 31, 2020 | |
Cash flows from operating activities: | ||
Net income | $ 39,228 | $ 42,804 |
Adjustments to reconcile net income to net cash provided by (used in) operating activities: | ||
Depreciation and amortization | 28,068 | 28,060 |
Regulatory debits | 348 | 291 |
Regulatory charges resulting from tax rate changes | 5,814 | 5,814 |
Amortization of deferred charges and credits | (772) | (821) |
Allowance for equity funds used during construction (equity AFUDC) | (215) | (241) |
Changes in current assets and liabilities: | ||
Trade and other accounts receivable | 1,822 | 5,132 |
Affiliated receivables | (9) | 29 |
Materials and supplies | (42) | (87) |
Other current assets | 1,872 | 3,840 |
Trade accounts payable | (8,375) | (1,676) |
Affiliated payables | 3,867 | (1,308) |
Other accrued liabilities | 6,175 | 578 |
Changes in noncurrent assets and liabilities: | ||
Regulatory liabilities | 957 | 1,079 |
Other, net | 85 | 636 |
Net cash provided by operating activities | 78,823 | 84,130 |
Cash flows from financing activities: | ||
Cash distributions to parent | (55,000) | (45,000) |
Net cash used in financing activities | (55,000) | (45,000) |
Property, plant and equipment: | ||
Capital expenditures | (7,426) | (9,562) |
Contributions and advances for construction costs | 1,699 | 4,094 |
Disposal of property, plant and equipment, net | (246) | (240) |
Advances to affiliates, net | (17,850) | (33,422) |
Net cash used in investing activities | (23,823) | (39,130) |
NET INCREASE (DECREASE) IN CASH | 0 | 0 |
CASH AT BEGINNING OF PERIOD | 0 | 0 |
CASH AT END OF PERIOD | 0 | 0 |
Increases to property, plant and equipment, exclusive of equity AFUDC | (5,741) | (5,520) |
Changes in related accounts payable and accrued liabilities | (1,685) | (4,042) |
Capital expenditures | $ (7,426) | $ (9,562) |
Basis of Presentation (Notes)
Basis of Presentation (Notes) | 3 Months Ended |
Mar. 31, 2021 | |
Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
Basis of Presentation | BASIS OF PRESENTATION In this report, Northwest Pipeline LLC (Northwest) is at times referred to in the first person as “we,” “us,” or “our.” Northwest is indirectly owned by The Williams Companies, Inc. (Williams). General The accompanying unaudited financial statements have been prepared from our books and records. Certain information and footnote disclosures normally included in financial statements prepared in accordance with U.S. generally accepted accounting principles (GAAP) have been condensed or omitted in this Form 10-Q pursuant to Securities and Exchange Commission rules and regulations. The unaudited financial statements include all normal recurring adjustments and others which, in the opinion of our management, are necessary to present fairly our interim financial statements. These unaudited financial statements should be read in conjunction with the financial statements and notes thereto in our 2020 Annual Report on Form 10-K. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the interim financial statements and accompanying notes. Actual results could differ from those estimates. |
Revenue Recognition (Notes)
Revenue Recognition (Notes) | 3 Months Ended |
Mar. 31, 2021 | |
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 Net Income . Contract Assets The following table presents a reconciliation of our contract assets: Three months ended March 31, 2021 2020 (Thousands) Balance at beginning of period $ 3,395 $ 554 Revenue recognized in excess of amounts invoiced 1,121 620 Balance at end of period $ 4,516 $ 1,174 Contract Liabilities The following table presents a reconciliation of our contract liabilities: Three months ended March 31, 2021 2020 (Thousands) Balance at beginning of period $ 4,610 $ 5,464 Recognized in Revenue (232) (213) Balance at end of period $ 4,378 $ 5,251 Remaining Performance Obligations Our remaining performance obligations 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 periodic review and approval by the Federal Energy Regulatory Commission (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. This table excludes the variable consideration component for commodity charges. Certain of our contracts contain evergreen provisions for periods beyond the initial term of the contract. The remaining performance obligations, as of March 31, 2021, do 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. The following table presents the amount of the contract liabilities balance expected to be recognized as revenue when performance obligations are satisfied and the transaction price allocated to the remaining performance obligations under certain contracts as of March 31, 2021. Contract Liabilities Remaining Performance Obligations (Thousands) 2021 (remainder) $ 707 $ 314,230 2022 1,029 410,694 2023 1,120 365,687 2024 1,218 334,497 2025 304 331,136 Thereafter — 2,645,508 Total $ 4,378 $ 4,401,752 Accounts Receivable Receivables from contracts with customers are included within Receivables - Trade and Receivables - Affiliated companies and receivables that are not related to contracts with customers are included within the balance of Receivables - Advances to affiliate and Receivables - Other in our Balance Sheet. |
Contingent Liabilities and Comm
Contingent Liabilities and Commitments (Notes) | 3 Months Ended |
Mar. 31, 2021 | |
Commitments and Contingencies Disclosure [Abstract] | |
Commitments and Contingencies Disclosure [Text Block] | 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 March 31, 2021, all of the meter stations have been remediated. During 2006 to 2018, 14 compressor stations were evaluated, of which 11 required remediation. As of March 31, 2021, 10 compressor stations have been remediated. At March 31, 2021, we had accrued liabilities totaling approximately $1.1 million, $0.2 million of which is recorded in Accrued liabilities - Other and $0.9 million of which is recorded in Other Noncurrent Liabilities - Other in the accompanying Balance Sheet. At December 31, 2020, we had accrued liabilities totaling approximately $1.1 million, $0.1 million of which is recorded in Accrued liabilities - Other and $1.0 million of which is recorded in Other Noncurrent Liabilities - Other in the accompanying Balance Sheet. 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 and combustion turbine 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 and Financing Arrangement
Debt and Financing Arrangement (Notes) | 3 Months Ended |
Mar. 31, 2021 | |
Debt Disclosure [Abstract] | |
Debt and Financing Arrangement | DEBT AND FINANCING ARRANGEMENTS Credit Facility We, along with Williams and Transcontinental Gas Pipe Line Company, LLC (Transco), are party to 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. Letter of credit commitments of $1.0 billion are subject to the $500 million borrowing sublimit applicable to us and Transco. At March 31, 2021, no letters of credit have been issued and no loans were outstanding under the credit facility. |
Financial Instruments (Notes)
Financial Instruments (Notes) | 3 Months Ended |
Mar. 31, 2021 | |
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: Short-term financial assets —The carrying values of short-term financial assets (advances to affiliate) that have variable interest rates, accounts receivable and accounts payable 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 were $578.3 million and $661.5 million, respectively, at March 31, 2021, and $578.0 million and $680.6 million, respectively, at December 31, 2020. |
Transactions with Affiliates (N
Transactions with Affiliates (Notes) | 3 Months Ended |
Mar. 31, 2021 | |
Related Party Transactions [Abstract] | |
Transactions with Affiliates | TRANSACTIONS WITH AFFILIATES We are a participant in Williams’ cash management program, and we make advances to and receive advances from Williams. At March 31, 2021 and December 31, 2020, our advances to Williams totaled approximately $265.7 million and $247.9 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 0.01 percent at March 31, 2021. The interest income from these advances was minimal and $0.5 million for the three months ended March 31, 2021 and 2020, respectively. Such interest income is included in Other (Income) and Other Expenses – Miscellaneous other (income) expenses, net on the accompanying Statement of Net Income. Included in Operating Revenues in the accompanying Statement of Net Income are revenues received from affiliates of $0.4 million and $0.2 million for the three months ended March 31, 2021 and 2020, respectively. The rates charged to provide services to affiliates are the same as those that are charged to similarly-situated nonaffiliated customers. 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 $22.1 million and $22.7 million in the three months ended March 31, 2021 and 2020, respectively, for these services. Such expenses are primarily included in General and administrative and Operation and maintenance expenses on the accompanying Statement of Net Income. During the three months ended March 31, 2021 and 2020, we declared and paid cash distributions to our parent of $55.0 million and $45.0 million, respectively. During April 2021, we declared and paid an additional cash distribution of $44.0 million to our parent. |
Revenue Recognition (Tables)
Revenue Recognition (Tables) | 3 Months Ended |
Mar. 31, 2021 | |
Revenue Recognition [Abstract] | |
Contract with Customer, Asset and Liability [Table Text Block] | Contract Assets The following table presents a reconciliation of our contract assets: Three months ended March 31, 2021 2020 (Thousands) Balance at beginning of period $ 3,395 $ 554 Revenue recognized in excess of amounts invoiced 1,121 620 Balance at end of period $ 4,516 $ 1,174 Contract Liabilities The following table presents a reconciliation of our contract liabilities: Three months ended March 31, 2021 2020 (Thousands) Balance at beginning of period $ 4,610 $ 5,464 Recognized in Revenue (232) (213) Balance at end of period $ 4,378 $ 5,251 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block] | The following table presents the amount of the contract liabilities balance expected to be recognized as revenue when performance obligations are satisfied and the transaction price allocated to the remaining performance obligations under certain contracts as of March 31, 2021. Contract Liabilities Remaining Performance Obligations (Thousands) 2021 (remainder) $ 707 $ 314,230 2022 1,029 410,694 2023 1,120 365,687 2024 1,218 334,497 2025 304 331,136 Thereafter — 2,645,508 Total $ 4,378 $ 4,401,752 |
Contract Assets (Details)
Contract Assets (Details) - USD ($) $ in Thousands | 3 Months Ended | |
Mar. 31, 2021 | Mar. 31, 2020 | |
Revenue Recognition [Abstract] | ||
Contract with Customer, Asset, after Allowance for Credit Loss - Balance at beginning of period | $ 3,395 | $ 554 |
Revenue recognized in excess of amounts invoiced | 1,121 | 620 |
Contract with Customer, Asset, after Allowance for Credit Loss - Balance at end of period | $ 4,516 | $ 1,174 |
Revenue Recognition Contract Li
Revenue Recognition Contract Liabilities (Details) - USD ($) $ in Thousands | 3 Months Ended | |||
Mar. 31, 2021 | Mar. 31, 2020 | Dec. 31, 2020 | Dec. 31, 2019 | |
Contract With Customer, Liability [Line Items] | ||||
Contract with Customer, Liability | $ 4,378 | $ 5,251 | $ 4,610 | $ 5,464 |
Recognized in revenue | $ (232) | $ (213) |
Contract Liabilities Performanc
Contract Liabilities Performance Obligation (Details) - USD ($) $ in Thousands | Mar. 31, 2021 | Dec. 31, 2020 | Mar. 31, 2020 | Dec. 31, 2019 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | ||||
Contract with Customer, Liability | $ 4,378 | $ 4,610 | $ 5,251 | $ 5,464 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01 | ||||
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | ||||
Contract with Customer, Liability | 707 | |||
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | ||||
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | ||||
Contract with Customer, Liability | 1,029 | |||
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | ||||
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | ||||
Contract with Customer, Liability | 1,120 | |||
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | ||||
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | ||||
Contract with Customer, Liability | 1,218 | |||
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 | ||||
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | ||||
Contract with Customer, Liability | 304 | |||
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 | ||||
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | ||||
Contract with Customer, Liability | $ 0 | |||
Performance Obligations Related To Contract Liabilities [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01 | ||||
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | ||||
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period | 9 months | |||
Performance Obligations Related To Contract Liabilities [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | ||||
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | ||||
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period | 1 year | |||
Performance Obligations Related To Contract Liabilities [Member] | 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, Expected Timing of Satisfaction, Period | 1 year | |||
Performance Obligations Related To Contract Liabilities [Member] | 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, Expected Timing of Satisfaction, Period | 1 year | |||
Performance Obligations Related To Contract Liabilities [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 | ||||
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | ||||
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period | 1 year | |||
Performance Obligations Related To Contract Liabilities [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 | ||||
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | ||||
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period | 1 year |
Remaining Performance Obligatio
Remaining Performance Obligation (Details) $ in Thousands | Mar. 31, 2021USD ($) |
Revenue Recognition [Abstract] | |
Revenue, Remaining Performance Obligation, Amount | $ 4,401,752 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01 | |
Revenue Recognition [Abstract] | |
Revenue, Remaining Performance Obligation, Amount | 314,230 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | |
Revenue Recognition [Abstract] | |
Revenue, Remaining Performance Obligation, Amount | 410,694 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | |
Revenue Recognition [Abstract] | |
Revenue, Remaining Performance Obligation, Amount | 365,687 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | |
Revenue Recognition [Abstract] | |
Revenue, Remaining Performance Obligation, Amount | 334,497 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 | |
Revenue Recognition [Abstract] | |
Revenue, Remaining Performance Obligation, Amount | 331,136 |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 | |
Revenue Recognition [Abstract] | |
Revenue, Remaining Performance Obligation, Amount | $ 2,645,508 |
Remaining Performance Obligations [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period | 9 months |
Remaining Performance Obligations [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period | 1 year |
Remaining Performance Obligations [Member] | 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, Expected Timing of Satisfaction, Period | 1 year |
Remaining Performance Obligations [Member] | 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, Expected Timing of Satisfaction, Period | 1 year |
Remaining Performance Obligations [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period | 1 year |
Remaining Performance Obligations [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items] | |
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period | 1 year |
Contingent Liabilities and Co_2
Contingent Liabilities and Commitments (Details) - Environmental assessment and remediation [Member] - USD ($) $ in Millions | Mar. 31, 2021 | Dec. 31, 2020 |
Site Contingency [Line Items] | ||
Accrued environmental assessment and remediation costs, total | $ 1.1 | $ 1.1 |
Accrued environmental assessment and remediation costs, current | 0.2 | 0.1 |
Accrued environmental assessment and remediation costs, noncurrent | $ 0.9 | $ 1 |
Debt and Financing Arrangemen_2
Debt and Financing Arrangement (Details) $ in Millions | Mar. 31, 2021USD ($) |
Williams Companies Inc [Member] | Letter of credit | |
Line of Credit Facility [Line Items] | |
Line of Credit Facility, Maximum Borrowing Capacity | $ 1,000 |
Credit Agreement [Member] | |
Line of Credit Facility [Line Items] | |
Line of Credit Facility, Maximum Borrowing Capacity | 500 |
Letters of Credit Outstanding, Amount | 0 |
Credit Agreement [Member] | Williams Companies Inc [Member] | |
Line of Credit Facility [Line Items] | |
Line of Credit Facility, Maximum Borrowing Capacity | 4,500 |
Additional Amount By Which Credit Facility Can Be Increased | 500 |
Line of credit facility, loans outstanding | 0 |
Letter of credit | |
Line of Credit Facility [Line Items] | |
Line of Credit Facility, Maximum Borrowing Capacity | 500 |
Commercial paper [Member] | Williams Companies Inc [Member] | |
Line of Credit Facility [Line Items] | |
Line of Credit Facility, Maximum Borrowing Capacity | 4,000 |
Commercial paper, outstanding | $ 0 |
Financial Instruments (Details)
Financial Instruments (Details) - USD ($) $ in Millions | Mar. 31, 2021 | Dec. 31, 2020 |
Carrying (reported) amount, fair value disclosure [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Long-term debt including current maturities | $ 578.3 | $ 578 |
Estimate of fair value, fair value disclosure [Member] | Fair value, inputs, level 2 [Member] | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Long-term debt including current maturities | $ 661.5 | $ 680.6 |
Transactions with Affiliates (D
Transactions with Affiliates (Details) $ in Thousands | 1 Months Ended | 3 Months Ended | ||
Apr. 30, 2021USD ($) | Mar. 31, 2021USD ($)employee | Mar. 31, 2020USD ($) | Dec. 31, 2020USD ($) | |
Related Party Transaction [Line Items] | ||||
Advances to affiliate | $ 265,719 | $ 247,869 | ||
Related party transaction, rate | 0.01% | |||
Entity number of employees | employee | 0 | |||
Related party transaction, expenses from transactions with related party | $ 22,100 | $ 22,700 | ||
Cash distributions to parent | 55,000 | 45,000 | ||
Subsequent Event [Member] | ||||
Related Party Transaction [Line Items] | ||||
Cash distributions to parent | $ 44,000 | |||
Affiliated Entity [Member] | ||||
Related Party Transaction [Line Items] | ||||
Revenue from Related Parties | 400 | 200 | ||
Williams Companies Inc [Member] | ||||
Related Party Transaction [Line Items] | ||||
Advances to affiliate | $ 265,700 | $ 247,900 | ||
Interest Income, Related Party | $ 500 |