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Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions | 1 Months Ended | 6 Months Ended |
--- | --- | --- | ---
Dec. 31, 2020 | Jul. 31, 2020 | Jun. 30, 2026 | Dec. 31, 2025
Commitments And Contingencies [Line Items] |  |  |  |
Accrued liabilities for environmental remediation |  |  | $ 17 | $ 21
Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration] |  |  | Other current liabilities, Other long-term liabilities | Other current liabilities, Other long-term liabilities
Loss Contingency, Damages Sought, Value |  | $ 187 |  |
Loss Contingency, Damages Paid, Value | $ 4 |  |  |
Guarantor Obligations, Origin and Purpose |  |  | GuaranteesDakota Access Pipeline We hold a 9.19 percent indirect interest in Dakota Access, which owns and operates the Bakken Pipeline system. In 2020, the U.S. District Court for the District of Columbia (the “D.D.C.”) ordered the United States Army Corps of Engineers (“Army Corps”), which granted permits and an easement for the Bakken Pipeline system, to prepare an environmental impact statement (“EIS”) relating to an easement under Lake Oahe in North Dakota. The D.D.C. later vacated the easement. The Army Corps issued the final EIS in late 2025 and recommended the continued operation of the pipeline. The Army Corps issued a Record of Decision in May of 2026. New litigation may be filed now that the final EIS has been issued. We have entered into a Contingent Equity Contribution Agreement whereby we, along with the other joint venture owners in the Bakken Pipeline system, have agreed to make equity contributions to the joint venture upon certain events occurring, such as vacatur of the easement resulting in a shutdown of the pipeline, to allow the entities that own and operate the Bakken Pipeline system to satisfy their senior note payment obligations.If the vacatur of the easement results in a temporary shutdown of the pipeline, we would have to contribute our 9.19 percent pro rata share of funds required to pay interest accruing on the notes and any portion of the principal that matures while the pipeline is shut down. We also expect to contribute our 9.19 percent pro rata share of any costs to remediate any deficiencies to reinstate the easement and/or return the pipeline into operation. If the vacatur of the easement results in a permanent shutdown of the pipeline, we would have to contribute our 9.19 percent pro rata share of the cost to redeem the bonds (including the one percent redemption premium required pursuant to the indenture governing the notes) and any accrued and unpaid interest. As of June 30, 2026, our maximum potential undiscounted payments under the Contingent Equity Contribution Agreement were approximately $78 million.WPC Parent, LLCOur maximum exposure to loss for WPC Parent, LLC includes a $109 million commitment to indemnify a joint venture member for our pro rata share of any payments made under a performance guarantee for construction of a pipeline by an equity method investee. |
Indirect Ownership Interest [Member] | Bakken Pipeline System [Member] |  |  |  |
Commitments And Contingencies [Line Items] |  |  |  |
Equity method investment, ownership percentage |  |  | 9.19% |
Financial Guarantee [Member] | Bakken Pipeline System [Member] | Guarantee of Indebtedness of Others [Member] |  |  |  |
Commitments And Contingencies [Line Items] |  |  |  |
Guarantor Obligations, Maximum Exposure, Undiscounted |  |  | $ 78 |
Performance Guarantee | WPC Parent, LLC |  |  |  |
Commitments And Contingencies [Line Items] |  |  |  |
Guarantor Obligations, Maximum Exposure, Undiscounted |  |  | $ 109 |

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