Basis of Presentation and Summary of Significant Accounting Policies (Policies)	9 Months Ended
Sep. 30, 2017
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies There were no material changes in our significant accounting policies from those described in our 2016 Annual Report on Form 10-K.
New Accounting Pronouncements Issued But Not Yet Adopted	New Accounting Pronouncements Issued But Not Yet Adopted As of September 30, 2017, the following accounting standards had not yet been adopted by us: In May 2014, the Financial Accounting Standards Board (FASB) issued ASU 2014-09, Revenue from Contracts with Customers, which outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes current revenue recognition guidance. We anticipate utilizing the modified retrospective method to adopt the provisions of this standard effective January 1, 2018 and are currently applying the provisions of the standard to our aggregated listing of gathering and processing, storage and transportation, and marketing, supply and logistics revenue contracts that involve revenue generating activities that occur after January 1, 2018. We are also in the process of implementing appropriate changes to our processes, systems and controls to support the accounting and disclosure requirements of the new standard. We are currently evaluating the impact that this standard will have on our consolidated financial statements, and currently believe that the standard will require us to begin classifying certain capital expenditure reimbursements received from our customers as deferred revenue rather than as reductions of property, plant and equipment in our consolidated financial statements. We currently anticipate that approximately $60 million to $70 million of these net reimbursements will be reclassified to net deferred revenue on January 1, 2018, which would result in a $15 million to $25 million cumulative effect of accounting change being recorded as an increase to partners' capital on January 1, 2018. In addition, we currently believe that the standard will require us to begin classifying service revenues on certain of our gathering and processing contracts as reductions of costs of product sold prospectively beginning January 1, 2018. We continue to evaluate the impact that this standard will have on our consolidated financial statements, especially as it relates to non-cash consideration received under certain of our gathering, processing, storage and transportation contracts. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), which revises the accounting for leases by requiring certain leases to be recognized as assets and liabilities on the balance sheet, and requiring companies to disclose additional information about their leasing arrangements. We expect to adopt the provisions of this standard effective January 1, 2019 and are currently evaluating the impact that this standard will have on our consolidated financial statements. In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments, which clarifies how certain cash receipts and cash payments are presented and classified in the statement of cash flows. We expect to adopt the provisions of this standard effective January 1, 2018 and are currently evaluating the impact that this standard may have on our consolidated financial statements. In January 2017, the FASB issued ASU 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment, which changes the annual quantitative goodwill impairment test to eliminate the current two step method and replace it with a single test to determine if goodwill is impaired and the amount of any impairment. We are required to adopt the provisions of this standard by January 1, 2020 and are currently evaluating the impact that this standard may have on our consolidated financial statements.

New Accounting Pronouncements Issued But Not Yet Adopted

As of September 30, 2017, the following accounting standards had not yet been adopted by us:

In May 2014, the Financial Accounting Standards Board (FASB) issued ASU 2014-09, Revenue from Contracts with Customers, which outlines a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers and supersedes current revenue recognition guidance. We anticipate utilizing the modified retrospective method to adopt the provisions of this standard effective January 1, 2018 and are currently applying the provisions of the standard to our aggregated listing of gathering and processing, storage and transportation, and marketing, supply and logistics revenue contracts that involve revenue generating activities that occur after January 1, 2018. We are also in the process of implementing appropriate changes to our processes, systems and controls to support the accounting and disclosure requirements of the new standard. We are currently evaluating the impact that this standard will have on our consolidated financial statements, and currently believe that the standard will require us to begin classifying certain capital expenditure reimbursements received from our customers as deferred revenue rather than as reductions of property, plant and equipment in our consolidated financial statements. We currently anticipate that approximately $60 million to $70 million of these net reimbursements will be reclassified to net deferred revenue on January 1, 2018, which would result in a $15 million to $25 million cumulative effect of accounting change being recorded as an increase to partners' capital on January 1, 2018. In addition, we currently believe that the standard will require us to begin classifying service revenues on certain of our gathering and processing contracts as reductions of costs of product sold prospectively beginning January 1, 2018. We continue to evaluate the impact that this standard will have on our consolidated financial statements, especially as it relates to non-cash consideration received under certain of our gathering, processing, storage and transportation contracts.

In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842), which revises the accounting for leases by requiring certain leases to be recognized as assets and liabilities on the balance sheet, and requiring companies to disclose additional information about their leasing arrangements. We expect to adopt the provisions of this standard effective January 1, 2019 and are currently evaluating the impact that this standard will have on our consolidated financial statements.

In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments, which clarifies how certain cash receipts and cash payments are presented and classified in the statement of cash flows. We expect to adopt the provisions of this standard effective January 1, 2018 and are currently evaluating the impact that this standard may have on our consolidated financial statements.

In January 2017, the FASB issued ASU 2017-04, Intangibles - Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment, which changes the annual quantitative goodwill impairment test to eliminate the current two step method and replace it with a single test to determine if goodwill is impaired and the amount of any impairment. We are required to adopt the provisions of this standard by January 1, 2020 and are currently evaluating the impact that this standard may have on our consolidated financial statements.