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Related Party Transactions - Additional Information (Detail) | 3 Months Ended | 6 Months Ended
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Jun. 30, 2021 | Jun. 30, 2020 | Jun. 30, 2021 | Jun. 30, 2020
LM4 |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Percentage of ownership in joint venture | 50.00% |  | 50.00% |
Credit Concentration Risk | Revenue |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Revenues attributable to fee based commercial agreements | 100.00% | 100.00% | 100.00% | 100.00%
Hess |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Percentage of ownership in joint venture | 50.00% |  | 50.00% |
Hess | Credit Concentration Risk | Revenue |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Revenues attributable to fee based commercial agreements | 100.00% | 100.00% | 100.00% | 100.00%
Hess | Amended and Restated Commercial Agreement |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Minimum volume commitments, Description |  |  | Minimum volume commitments (“MVCs”) are equal to 80% of Hess’ nominations in each development plan that apply on a three-year rolling basis such that MVCs are set for the three years following the most recent nomination. Without our consent, the MVCs resulting from the nominated volumes for any quarter or year contained in any prior development plan shall not be reduced by any updated development plan unless dedicated production is released by us. The applicable MVCs may, however, be increased as a result of the nominations contained in any such updated development plan. |
Minimum volume commitments expressed as percentage of related party nominations in development plans |  |  | 80.00% |
Initial term of agreement |  |  | 10 years |
Agreement description |  |  | each of our commercial agreements with Hess has an initial 10-year term effective January 1, 2014 (“Initial Term”). |
Number of rights to extend the term of agreement |  |  | one |
Advance period to call for extension of term of agreement |  |  | 3 years |
Secondary term of agreement |  |  | 10 years |
Hess | Amended and Restated Agreement for Certain Gas Gathering Sub-system |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Initial term of agreement |  |  | 15 years |
Agreement description |  |  | For this gathering sub-system, the Initial Term is 15 years effective January 1, 2014 and for the water services agreements the Initial Term is 14 years effective January 1, 2019. |
Secondary term of agreement |  |  | 5 years |
Hess | Amended and Restated Water Services Agreements |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Initial term of agreement |  |  | 14 years |
Secondary term of agreement |  |  | 10 years |
Hess | Terminal and Export Services Agreement |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Commercial agreement period |  |  | 20 years |
Hess | Commercial Agreements Other Than Storage Services Agreement and Terminal and Export Services Agreement |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Minimum volume commitments, Description |  |  | During the Secondary Term of our commercial agreements, Hess will continue to have MVCs equal to 80% of Hess’ nominations in each development plan that apply on a three-year rolling basis through the Secondary Term. |
Minimum volume commitments expressed as percentage of related party nominations in development plans |  |  | 80.00% |
Maximum consumer price index percentage |  |  | 3.00% |
Fee recalculation model description |  |  | the fee recalculation model under each applicable agreement will be replaced by an inflation-based fee structure. The initial fee for the first year of the Secondary Term will be determined based on the average fees paid by Hess under the applicable agreement during the last three years of the Initial Term (with such fees adjusted for inflation through the first year of the Secondary Term). For each year following the first year of the Secondary Term, the applicable fee will be adjusted annually based on the percentage change in the consumer price index, provided that we may not increase any fee by more than 3% in any calendar year solely by reason of an increase in the consumer price index, and no fee will ever be reduced below the amount of the applicable fee payable by Hess in the prior year as a result of a decrease in the consumer price index. |
Targa Resources Corp. | LM4 |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Percentage of ownership in joint venture | 50.00% |  | 50.00% |

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