Summary of Significant Accounting Policies | (2) Summary of Significant Accounting Policies (a) These consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”). In the opinion of management, these statements include all adjustments considered necessary for a fair presentation of the Partnership’s financial position as of December 31, 2017 and 2018, and the results of the Partnership’s operations and its cash flows for the years ended December 31, 2016, 2017, and 2018. The Partnership has no items of other comprehensive income or loss; therefore, net income is identical to comprehensive income. Certain costs of doing business incurred by Antero Resources on our behalf have been reflected in the accompanying consolidated financial statements. These costs include general and administrative expenses attributed to us by Antero Resources in exchange for: business services, such as payroll, accounts payable and facilities management; corporate services, such as finance and accounting, legal, human resources, investor relations and public and regulatory policy; and employee compensation, including equity‑based compensation. Transactions between the Partnership and Antero Resources have been identified in the consolidated financial statements (see Note 3—Transactions with Affiliates). As of the date these consolidated financial statements were filed with the SEC, the Partnership completed its evaluation of potential subsequent events for disclosure and no items requiring disclosure were identified, except the declaration of a cash distribution to unitholders, as described in Note 10—Partnership Equity and Distributions. (b) On May 28, 2014, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers , which requires an entity to recognize the amount of revenue to which it expects to be entitled for the transfer of promised goods or services to customers. The ASU replaced most existing revenue recognition guidance in GAAP when it became effective and was incorporated into GAAP as Accounting Standards Codification (“ASC”) Topic 606. The Partnership elected the modified retrospective transition method when new standard became effective for the Partnership on January 1, 2018. The adoption of ASU 2014-09 did not have a material impact on the Partnership’s financial results. The Partnership provides gathering and compression and water handling and treatment services under fee-based contracts primarily based on throughput or at cost plus a margin. Certain of these contracts contain operating leases of the Partnership’s assets under GAAP. Under these arrangements, the Partnership receives fees for gathering oil and gas products, compression services, and water handling and treatment services. The revenue the Partnership earns from these arrangements is directly related to (1) in the case of natural gas gathering and compression, the volumes of metered natural gas that it gathers, compresses, and delivers to natural gas compression sites or other transmission delivery points, (2) in the case of oil gathering, the volumes of metered oil that it gathers and delivers to other transmission delivery points, (3) in the case of fresh water services, the quantities of fresh water delivered to its customers for use in their well completion operations, (4) in the case of wastewater treatment services performed by the Partnership, the quantities of wastewater treated for our customers, or (5) in the case of flowback and produced water services provided by third parties, the third party costs the Partnership incurs plus 3%. The Partnership recognizes revenue when it satisfies a performance obligation by delivering a service to a customer or the use of leased assets to a customer. See Note 4—Revenue for the Partnership’s required disclosures under ASC 606. The Partnership report includes lease revenue within service revenue. (c) The preparation of the consolidated financial statements and notes in conformity with GAAP requires that management formulate estimates and assumptions that affect revenues, expenses, assets, liabilities and the disclosure of contingent assets and liabilities. Items subject to estimates and assumptions include the useful lives of property and equipment and valuation of accrued liabilities, among others. Although management believes these estimates are reasonable, actual results could differ from these estimates. (d) The Partnership considers all liquid investments purchased with an initial maturity of three months or less to be cash equivalents. The carrying value of cash and cash equivalents approximates fair value due to the short-term nature of these instruments. From time to time, the Partnership may be in the position of a “book overdraft” in which outstanding checks exceed cash and cash equivalents. The Partnership classifies book overdrafts in accounts payable within its consolidated balance sheets, and classifies the change in accounts payable associated with book overdrafts as an operating activity within its consolidated statements of cash flows. The Partnership classified $0.5 million of book overdrafts within accounts payable as of December 31, 2018. (e) Property and equipment primarily consists of gathering pipelines, compressor stations, fresh water delivery pipelines and facilities, and the wastewater treatment facility and related landfill used for the disposal of waste therefrom, stated at historical cost less accumulated depreciation and amortization. The Partnership capitalizes construction-related direct labor and material costs. The Partnership also capitalized interest on capital costs during the construction phase of the wastewater treatment facility, which was placed in service in 2018. Maintenance and repair costs are expensed as incurred. Depreciation is computed using the straight-line method over the estimated useful lives and salvage values of assets. The depreciation of fixed assets recorded under capital lease agreements is included in depreciation expense. Uncertainties that may impact these estimates of useful lives include, among others, changes in laws and regulations relating to environmental matters, including air and water quality, restoration and abandonment requirements, economic conditions, and supply and demand for the Partnership’s services in the areas in which it operates. When assets are placed into service, management makes estimates with respect to useful lives and salvage values that management believes are reasonable. However, subsequent events could cause a change in estimates, thereby impacting future depreciation amounts. Amortization of landfill airspace consists of the amortization of landfill capital costs, including those that have been incurred and capitalized and estimated future costs for landfill development and construction, as well as the amortization of asset retirement costs arising from landfill final capping, closure, and post-closure obligations. Amortization expense is recorded on a units-of-consumption basis, applying cost as a rate per-cubic yard. The rate per-cubic yard is calculated by dividing each component of the amortizable basis of the landfill by the number of cubic yards needed to fill the corresponding asset’s airspace. Landfill capital costs and closure and post-closure asset retirement costs are generally incurred to support the operation of the landfill over its entire operating life and are, therefore, amortized on a per-cubic yard basis using a landfill’s total airspace capacity. Estimates of disposal capacity and future development costs are created using input from independent engineers and internal technical teams and are reviewed at least annually. However, future events could cause a change in estimates, thereby impacting future amortization amounts. See Note 5—Property and Equipment for discussion on the change in estimated useful lives for the Partnership’s gathering system and facilities. (f) The Partnership evaluates its long‑lived assets for impairment when events or changes in circumstances indicate that the related carrying values of the assets may not be recoverable. Generally, the basis for making such assessments are undiscounted future cash flows projections for the asset group being assessed. If the carrying values of the assets are deemed not recoverable, the carrying values are reduced to the estimated fair value, which are based on discounted future cash flows using assumptions as to revenues, costs and discount rates typical of third party market participants, which is a Level 3 fair value measurement. (g) In December 2017, the Partnership completed the construction of a landfill site to be used for the disposal of waste from its wastewater treatment facility. The landfill began accepting waste in January 2018. The Partnership’s asset retirement obligations relate to its obligation to close, maintain, and monitor landfill cells and support facilities. After the entire landfill reaches capacity and is certified closed, the Partnership must continue to maintain and monitor the landfill for a post-closure period, which generally extends for 30 years. The Partnership records the fair value of its landfill retirement obligations as a liability in the period in which the regulatory obligation to retire a specific asset is triggered. For the Partnership’s individual landfill cells, the required closure and post-closure obligations under the terms of its permits and its intended operation of the landfill cell are triggered and recorded when the cell is placed into service and waste is initially disposed in the landfill cell. The fair value is based on the total estimated costs to close the landfill cell and perform post-closure activities once the landfill cell has reached capacity and is no longer accepting waste. Retirement obligations are increased each year to reflect the passage of time by accreting the balance at the weighted average credit-adjusted risk-free rate that is used to calculate the recorded liability, with accretion charged to direct costs. Actual cash expenditures to perform closure and post-closure activities reduce the retirement obligation liabilities as incurred. After initial measurement, asset retirement obligations are adjusted at the end of each period to reflect changes, if any, in the estimated future cash flows underlying the obligation. Landfill retirement assets are capitalized as the related retirement obligations are incurred, and are amortized on a units-of-consumption basis as the disposal capacity is consumed. A retirement obligation is created for fresh water impoundments and waste water pits when an abandonment date is identified. The Partnership records the fair value of its freshwater impoundment and waste water pit retirement obligations as liabilities in the period in which the regulatory obligation to retire a specific asset is triggered. The fair value is based on the total reclamation costs of the assets. Retirement obligations are increased each year to reflect the passage of time by accreting the balance at the weighted average credit-adjusted risk-free rate that is used to calculate the recorded liability, with accretion charged to direct costs. Actual cash expenditures to perform remediation activities reduce the retirement obligation liabilities as incurred. After initial measurement, asset retirement obligations are adjusted at the end of each period to reflect changes, if any, in the estimated future cash flows underlying the obligation. Fresh water impoundments and waster water pit retirement assets are capitalized as the related retirement obligations are incurred, and are amortized on a straight-line basis until reclamation. The Partnership is under no legal obligations, neither contractually nor under the doctrine of promissory estoppel, to restore or dismantle its gathering pipelines, compressor stations, water delivery pipelines and facilities and wastewater treatment facility upon abandonment. The Partnership’s gathering pipelines, compressor stations, fresh water delivery pipelines and facilities and wastewater treatment facility have an indeterminate life, if properly maintained. Accordingly, the Partnership is not able to make a reasonable estimate of when future dismantlement and removal dates of its pipelines, compressor stations and facilities will occur. (h) A liability is recorded for a loss contingency when its occurrence is probable and damages can be reasonably estimated based on the anticipated most likely outcome or the minimum amount within a range of possible outcomes. The Partnership regularly reviews contingencies to determine the adequacy of our accruals and related disclosures. The ultimate amount of losses, if any, may differ from these estimates. The Partnership accrues losses associated with environmental obligations when such losses are probable and can be reasonably estimated. Accruals for estimated environmental losses are recognized no later than at the time a remediation feasibility study, or an evaluation of response options, is complete. These accruals are adjusted as additional information becomes available or as circumstances change. Future environmental expenditures are not discounted to their present value. Recoveries of environmental costs from other parties are recorded separately as assets at their undiscounted value when receipt of such recoveries is probable. As of December 31, 2017 and 2018, the Partnership has not recorded liabilities for litigation, environmental, or other contingencies. (i) The Partnership’s consolidated financial statements reflect various equity-based compensation awards granted by Antero Resources, as well as compensation expense associated with its own plan. These awards include profits interests awards, restricted stock, stock options, restricted units, and phantom units. The Partnership recognized expense in each period for an amount allocated from Antero Resources, with the offset included in partners’ capital. See Note 3—Transactions with Affiliates for additional information regarding Antero Resources’ allocation of expenses to the Partnership. In connection with the Partnership’s Initial Public Offering (“IPO”), the Antero Midstream Partners LP Long-Term Incentive Plan (“Midstream LTIP”) was adopted, pursuant to which certain non-employee directors of our general partner and certain officers, employees and consultants of the Partnership’s general partner and its affiliates are eligible to receive awards representing equity interests in the Partnership. An aggregate of 10,000,000 common units may be delivered pursuant to awards under the Midstream LTIP, subject to customary adjustments. For accounting purposes, these units are treated as if they are distributed from the Partnership to Antero Resources. Antero Resources recognizes compensation expense for the units awarded to its employees and a portion of that expense is allocated to the Partnership. See Note 9—Equity-Based Compensation. (j) These consolidated financial statements do not include a provision for income taxes as Antero Midstream Partners LP is treated as a partnership for federal and state income tax purposes, with each partner being separately taxed on its distributive share of our items of income, gain, loss, or deduction. (k) The FASB Accounting Standards Codification Topic 820, Fair Value Measurements and Disclosures , clarifies the definition of fair value, establishes a framework for measuring fair value, and expands disclosures about fair value measurements. This guidance also relates to all nonfinancial assets and liabilities that are not recognized or disclosed on a recurring basis (e.g., the initial recognition of asset retirement obligations and impairments of long‑lived assets). The fair value is the price that the Partnership estimates would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. A fair value hierarchy is used to prioritize inputs to valuation techniques used to estimate fair value. An asset or liability subject to the fair value requirements is categorized within the hierarchy based on the lowest level of input that is significant to the fair value measurement. The Partnership’s assessment of the significance of a particular input to the fair value measurement in its entirety requires judgment and considers factors specific to the asset or liability. The highest priority (Level 1) is given to unadjusted quoted market prices in active markets for identical assets or liabilities, and the lowest priority (Level 3) is given to unobservable inputs. Level 2 inputs are data, other than quoted prices included within Level 1, that are observable for the asset or liability, either directly or indirectly. The carrying values on the Partnership’s balance sheet of its cash and cash equivalents, accounts receivable–Antero Resources, accounts receivable–third party, other current assets, other assets, accounts payable–Antero Resources, accounts payable, accrued liabilities, other current liabilities, other liabilities and the revolving credit facility approximate fair values due to their short-term maturities. (l) The Partnership uses the equity method to account for its investments in companies if the investment provides the Partnership with the ability to exercise significant influence over, but not control, the operating and financial policies of the investee. The Partnership’s consolidated net income includes the Partnership’s proportionate share of the net income or loss of such companies. The Partnership’s judgment regarding the level of influence over each equity method investee includes considering key factors such as the Partnership’s ownership interest, representation on the board of directors and participation in policy-making decisions of the investee and material intercompany transactions. See Note 14—Investments in Unconsolidated Affiliates. (m) On February 25, 2016, the FASB issued ASU No. 2016-02, Leases , which replaced most existing lease guidance under GAAP when it became effective on January 1, 2019. The standard requires lessees to record lease liabilities and right-of-use assets as of the date of adoption and we have elected to adopt the new standard prospectively. The Partnership is not a party to any material contracts as a lessee. The new lease standard does not substantially change accounting by lessors. The Partnership determined that its contractual arrangement with Antero Resources to provide midstream services is an operating lease of the Partnership’s assets that will be accounted under the new ASU for in the same manner as the Partnership’s current accounting for the arrangement. No significant additional disclosures will be required. As a result, there will not be a material impact of the new leasing standard on the Partnership’s financial statements. The Partnership believes that adoption of the standard will not impact its operational strategies, growth prospects, net income, or cash flow. The Partnership as updated internal controls impacted by the new standard and acquired software to collect and account for lease data under the standard. |