Shell Midstream Partners (SHLX) 10-Q 5 May 17 2017 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2017	May 05, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q1
Trading Symbol	SHLX
Entity Registrant Name	Shell Midstream Partners, L.P.
Entity Central Index Key	1,610,466
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding (in shares)		177,317,444

UNAUDITED CONDENSED CONSOLIDATE

UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Current assets
Cash and cash equivalents	$ 154.6	$ 121.9
Accounts receivable – third parties, net	16.1	18.4
Accounts receivable – related parties	13.3	10.1
Allowance oil	7.9	9
Prepaid expenses	6.5	6
Total current assets	198.4	165.4
Equity method investments	256.8	262.4
Property, plant and equipment, net	403.8	398
Cost investments	39.8	39.8
Total assets	898.8	865.6
Current liabilities
Accounts payable – third parties	0.8	1.5
Accounts payable – related parties	5.7	5.2
Deferred revenue – third parties	7.8	6
Deferred revenue – related parties	14.2	7.9
Accrued liabilities – third parties	12.7	5.6
Accrued liabilities – related parties	6.2	5.1
Total current liabilities	47.4	31.3
Noncurrent liabilities
Debt payable – related party	685.3	686
Lease liability – related party	24.7	24.9
Asset retirement obligations	1.4	1.4
Other unearned income	2.5	2.1
Total noncurrent liabilities	713.9	714.4
Total liabilities	761.3	745.7
Commitments and Contingencies (Note 10)
EQUITY
Total partners' capital	116.9	98.3
Noncontrolling interest	20.6	21.6
Total equity	137.5	119.9
Total liabilities and equity	898.8	865.6
Shell Pipeline Company L P
EQUITY
General partner unitholders	(1,864.7)	(1,873.7)
Common Units | General Public
EQUITY
Limited partner unitholders	2,490.5	2,485.7
Common Units | Shell Pipeline Company L P
EQUITY
Limited partner unitholders	(508.9)	(124.1)
Subordinated Units | Shell Pipeline Company L P
EQUITY
Limited partner unitholders	0	(389.6)
Total equity	$ 0	$ (389.6)

UNAUDITED CONDENSED CONSOLIDAT3

UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - shares	Mar. 31, 2017	Dec. 31, 2016
Limited partners' capital account, units outstanding (in units)	177,317,444
Shell Pipeline Company L P
General partners' capital account, units issued (in units)	3,618,723	3,618,723
General partners' capital account, units outstanding (in units)	3,618,723	3,618,723
Common Units | General Public
Limited partners' capital account, units issued (in units)	88,367,308	88,367,308
Limited partners' capital account, units outstanding (in units)	88,367,308	88,367,308
Common Units | Shell Pipeline Company L P
Limited partners' capital account, units issued (in units)	88,950,136	21,475,068
Limited partners' capital account, units outstanding (in units)	88,950,136	21,475,068
Subordinated Units | Shell Pipeline Company L P
Limited partners' capital account, units issued (in units)	0	67,475,068
Limited partners' capital account, units outstanding (in units)	0	67,475,068

UNAUDITED CONDENSED CONSOLIDAT4

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Revenue
Third parties	$ 47.3	$ 51.3
Related parties	22.9	25.4
Total revenue	70.2	76.7
Costs and expenses
Operations and maintenance – third parties	12.9	9.4
Operations and maintenance – related parties	8.5	5.4
General and administrative – third parties	1.6	2.1
General and administrative – related parties	6.4	5.7
Depreciation, amortization and accretion	6.2	5.9
Property and other taxes	2.8	3.2
Total costs and expenses	38.4	31.7
Operating income	31.8	45
Income from equity investments	38.7	23.2
Dividend income from cost investments	7.3	2.8
Investment and dividend income	46	26
Interest expense, net	4.8	3
Income before income taxes	73	68
Income tax expense	0	0
Net income	73	68
Less: Net income attributable to noncontrolling interests	2.2	12.7
Net income attributable to the Partnership	70.8	55.3
Limited Partners' interest in net income attributable to the Partnership	$ 58.7	$ 52.2
Net income per Limited Partner Unit - Basic and Diluted:
Distributions declared per Limited Partner Unit (in dollars per unit)	$ 0.291	$ 0.2350
Shell Pipeline Company L P
Costs and expenses
General partner's interest in net income attributable to the Partnership	$ 12.1	$ 3.1
Common
Costs and expenses
Net income attributable to the Partnership	$ 58.7	$ 30.5
Net income per Limited Partner Unit - Basic and Diluted:
Net income per Limited Partner Unit (in dollars per share)	$ 0.33	$ 0.36
Subordinated
Costs and expenses
Net income attributable to the Partnership		$ 21.7
Net income per Limited Partner Unit - Basic and Diluted:
Net income per Limited Partner Unit (in dollars per share)	$ 0	$ 0.32
Common units – public
Costs and expenses
Net income	$ 29.3
Weighted average Limited Partner Units outstanding - Basic and Diluted (in millions):
Weighted average limited partner units - Common (in shares)	88.4	63.4
Common units – public | Shell Pipeline Company L P
Costs and expenses
Net income	$ 29.4
Common units – SPLC | Shell Pipeline Company L P
Weighted average Limited Partner Units outstanding - Basic and Diluted (in millions):
Weighted average limited partner units - Common (in shares)	88.9	21.5
Subordinated units – SPLC | Shell Pipeline Company L P
Weighted average Limited Partner Units outstanding - Basic and Diluted (in millions):
Weighted average limited partner units - Subordinated (in shares)	0	67.5

UNAUDITED CONDENSED CONSOLIDAT5

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash flows from operating activities
Net income	$ 73	$ 68
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation, amortization and accretion	6.2	5.9
Non-cash interest expense	0	0.1
Undistributed equity earnings	(0.8)	(1)
Changes in operating assets and liabilities
Accounts receivable	2.7	0.3
Allowance oil	1.1	(0.4)
Prepaid expenses	(0.5)	1.6
Accounts payable	(0.1)	(0.2)
Deferred revenue	8.5	(1.8)
Accrued liabilities	3.4	(0.1)
Net cash provided by operating activities	93.5	72.4
Cash flows from investing activities
Capital expenditures	(7.3)	(4.7)
Purchase price adjustment	0.4	0
Return of investment	6	4.1
Net cash used in investing activities	(0.9)	(0.6)
Cash flows from financing activities
Net proceeds from public offerings	0	420.4
Contributions from general partner	0	8.7
Repayment of credit facilities	0	(410)
Distributions to noncontrolling interest	(3.2)	(12.4)
Distributions to unitholders and general partner	(58.6)	(35.3)
Other contribution from parent	2.8	1.8
Capital lease payments	(0.2)	0
Credit facilities issuance costs	(0.7)	0
Net cash used in financing activities	(59.9)	(26.8)
Net increase in cash and cash equivalents	32.7	45
Cash and cash equivalents at beginning of the period	121.9	93
Cash and cash equivalents at end of the period	154.6	138
Non-cash investing and financing transactions
Change in accrued capital expenditures	4.7	0.4
Other non-cash contributions from Parent	$ 3.8	$ 0.1

UNAUDITED CONDENSED CONSOLIDAT6

UNAUDITED CONDENSED CONSOLIDATED STATEMENT OF CHANGES IN EQUITY - 3 months ended Mar. 31, 2017 - USD ($) $ in Millions	Total	Noncontrolling Interest	Common units – public	Common units – publicShell Pipeline Company L P	Subordinated UnitsShell Pipeline Company L P	General PartnerShell Pipeline Company L P
Beginning Balance at Dec. 31, 2016	$ 119.9	$ 21.6	$ 2,485.7	$ (124.1)	$ (389.6)	$ (1,873.7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	73	2.2	29.3	29.4		12.1
Other contribution from parent	6.4					6.4
Distributions to unitholders and general partner	(58.6)		(24.5)	(5.9)	(18.7)	(9.5)
Distribution to noncontrolling interest	(3.2)	(3.2)
Expiration of subordinated period				(408.3)	408.3
Ending Balance at Mar. 31, 2017	$ 137.5	$ 20.6	$ 2,490.5	$ (508.9)	$ 0	$ (1,864.7)

Description of Business and Bas

Description of Business and Basis of Presentation	3 Months Ended
	Mar. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Basis of Presentation	Description of Business and Basis of Presentation Shell Midstream Partners, L.P. (“we,” “us,” “our” or “the Partnership”) is a Delaware limited partnership formed on March 19, 2014 to own and operate assets, including certain assets received from Shell Pipeline Company LP (“SPLC”). We conduct our operations through our wholly owned subsidiary Shell Midstream Operating, LLC (“Operating Company”). Our general partner is Shell Midstream Partners GP LLC (“general partner”). References to “Shell” or “Parent” refer collectively to Royal Dutch Shell plc (“RDS”) and its controlled affiliates, other than us, our subsidiaries and our general partner. On November 3, 2014, we completed our Initial Public Offering (“IPO”), and our common units trade on the New York Stock Exchange under the symbol “SHLX.” Description of Business We are a fee-based, growth-oriented master limited partnership formed by Shell to own, operate, develop and acquire pipelines and other midstream assets. Our assets consist of interests in entities that own crude oil and refined products pipelines serving as key infrastructure to transport onshore and offshore crude oil production to Gulf Coast and Midwest refining markets and to deliver refined products from those markets to major demand centers. As of March 31, 2017 , we own interests in seven crude oil pipeline systems, three refined products systems, one natural gas gathering pipeline system and a crude tank storage and terminal system. The crude oil pipeline systems include the Auger Pipeline System (“Auger”), held by Pecten Midstream LLC (“Pecten”), Zydeco Pipeline Company LLC (“Zydeco”), Odyssey Pipeline LLC (“Odyssey”), Mars Oil Pipeline Company (“Mars”), Poseidon Oil Pipeline Company LLC (“Poseidon”), Proteus Oil Pipeline Company, LLC (“Proteus”), and Endymion Oil Pipeline Company, LLC (“Endymion”), and are strategically located along the Texas and Louisiana Gulf Coast and in the Gulf of Mexico. These systems link major onshore and offshore production areas with key refining markets. The refined products pipeline systems, which are held by Bengal Pipeline Company LLC (“Bengal”) and Colonial Pipeline Company (“Colonial”), connect Gulf Coast and southeastern U.S. refineries to major demand centers from Alabama to New York, and Explorer Pipeline Company (“Explorer”) which serves more than 70 major cities in 16 states from the Gulf Coast to the Midwest. The natural gas pipeline system, Cleopatra Gas Gathering Company, LLC (“Cleopatra”), brings Gulf of Mexico gas production to the market hub at Ship Shoal 332. The crude storage terminal, Lockport Terminal (“Lockport”), is located southwest of Chicago and serves Midwest refineries. As of March 31, 2017 , we own a 100% interest in Pecten, a 92.5% interest in Zydeco, a 50.0% interest in Bengal, a 49.0% interest in Odyssey, a 48.6% interest in Mars, a 36.0% interest in Poseidon, a 10.0% interest in Proteus, a 10.0% interest in Endymion, a 6.0% interest in Colonial, a 2.62% interest in Explorer and a 1.0% interest in Cleopatra. Each of Pecten and Zydeco is consolidated within our condensed consolidated financial statements as a subsidiary. The 7.5% ownership interest in Zydeco retained by SPLC is reflected as noncontrolling interest in our condensed consolidated financial statements. We account for each of our investments in Bengal, Odyssey, Mars, Poseidon, Proteus and Endymion using the equity method of accounting, and we account for each of our investments in Colonial, Explorer and Cleopatra using the cost method of accounting. We generate a substantial portion of our revenue under long-term agreements by charging fees for the transportation and storage of crude oil and refined products through our pipelines and storage tanks and from income from our equity and cost method investments. Our operations consist of one reportable segment. Basis of Presentation Our condensed consolidated financial statements include all majority owned and non-majority owned subsidiaries required to be consolidated under generally accepted accounting principles in the United States (“GAAP”). Our reporting currency is U.S. dollars, and all references to dollars are U.S. dollars. The accompanying unaudited condensed consolidated financial statements and related notes have been prepared in accordance with GAAP for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and notes required by GAAP for complete annual financial statements. The year-end condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP. During interim periods, we follow the accounting policies disclosed in our Annual Report on Form 10-K for the year ended December 31, 2016 (our “2016 Annual Report”), filed with the United States Securities and Exchange Commission (“SEC”). The unaudited condensed consolidated financial statements for the three months ended March 31, 2017 and 2016 include all adjustments we believe are necessary for a fair statement of the results for the interim periods. These adjustments are of a normal recurring nature unless otherwise disclosed. Operating results for the three months ended March 31, 2017 are not necessarily indicative of the results that may be expected for the full year. These unaudited condensed consolidated financial statements and other information included in this Quarterly Report on Form 10-Q should be read in conjunction with our consolidated financial statements and notes thereto included in our 2016 Annual Report. Summary of Significant Accounting Policies The accounting policies are set forth in Note 2—Summary of Significant Accounting Policies in the Notes to Consolidated Financial Statements of our 2016 Annual Report. There have been no significant changes to these policies during the three months ended March 31, 2017 . Recently Adopted Accounting Pronouncements In October 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-17 to Topic 810, Consolidation, making changes on how a reporting entity should treat indirect interests in an entity held through related parties that are under common control with the reporting entity when determining whether it is the primary beneficiary of a variable interest entity. The update was effective for us as of January 1, 2017. The adoption of this update did not have a material impact on our financial statements. In March 2016, the FASB issued ASU 2016-07 to Topic 323, Investments - Equity Method and Joint Ventures, to eliminate the need for an entity to retroactively adopt the equity method of accounting when an investment becomes qualified for the use of the equity method of accounting due to an increase in level of ownership or degree of influence. The update was effective for us as of January 1, 2017. The adoption of this update did not have a material impact on our financial statements. Recent Accounting Pronouncements In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers, which will supersede nearly all existing revenue recognition guidance under GAAP. The update's core principle is that a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The update is effective for fiscal years and interim periods within those fiscal years beginning after December 15, 2017. The update allows for either “full retrospective” adoption, meaning the standard is applied to all of the periods presented, or “modified retrospective” adoption, meaning the standard is applied only to the most current period presented in the financial statements. We continue to evaluate our existing revenue recognition policies to determine whether any contracts in the scope of the guidance will be affected by the new requirements. We have not yet selected a transition method nor have we determined the effect of the update on our consolidated results of operations, financial position or cash flows. For additional information on accounting pronouncements issued prior to March 2017, refer to Note 2—Summary of Significant Accounting Policies in the Notes to Consolidated Financial Statements of our 2016 Annual Report.

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2017
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Related party transactions include transactions with SPLC and Shell, including those entities in which Shell has an ownership interest but does not have control. Acquisition Agreements For a discussion of related party acquisition agreements, see Note 4—Related Party Transactions in the Notes to Consolidated Financial Statements of our 2016 Annual Report. Commercial Agreements Omnibus Agreement On November 3, 2014, in connection with the IPO and the acquisition of Zydeco, we entered into an Omnibus Agreement with SPLC and our general partner concerning our payment of an annual general and administrative services fee to SPLC as well as our reimbursement of certain costs incurred by SPLC on our behalf. This agreement addresses the following matters: • our payment of an annual general and administrative fee of $8.5 million for the provision of certain services by SPLC; • our obligation to reimburse SPLC for certain direct or allocated costs and expenses incurred by SPLC on our behalf; • our obligation to reimburse SPLC for all expenses incurred by SPLC as a result of us becoming and continuing as a publicly traded entity; we will reimburse our general partner for these expenses to the extent the fees relating to such services are not included in the general and administrative fee; and • the granting of a license from Shell to us with respect to using certain Shell trademarks and trade names. Indemnification for any unknown environmental liabilities is limited to liabilities due to occurrences prior to the closing of the IPO and that are identified before the third anniversary of the closing of the IPO. SPLC will indemnify us for tax liabilities which are identified prior to the date that is 60 days after the expiration of the statute of limitations applicable to such liabilities. We have agreed to indemnify SPLC for events and conditions associated with the ownership or operation of our assets (other than any environmental liabilities for which SPLC is specifically required to indemnify us as described above). There is no limit on the amount for which we will indemnify SPLC under the Omnibus Agreement. Under the Omnibus Agreement, certain costs are indemnified by SPLC. The legal and environmental indemnifications are subject to individual $0.5 million deductibles, while we have an aggregate limit of $15.0 million , of which $10.7 million is remaining. As of March 31, 2017 , only the environmental indemnification remains and it will expire in November 2017. During the three months ended March 31, 2017 , we did not make any claims for indemnification under the Omnibus Agreement. Tax Sharing Agreement For a discussion of the Tax Sharing Agreement, see Note 4—Related Party Transactions in the Notes to Consolidated Financial Statements of our 2016 Annual Report. Other Agreements In connection with the IPO and our acquisitions from Shell, we have entered into several customary agreements with SPLC and Shell. These agreements include pipeline operating agreements, reimbursement agreements and services agreements. Noncontrolling Interest Noncontrolling interest consists of SPLC's 7.5% retained ownership interest in Zydeco as of March 31, 2017 and December 31, 2016 . During the three months ended March 31, 2017 and 2016, SPLC owned a 7.5% and 37.5% noncontrolling interest in Zydeco, respectively. Other Related Party Balances Other related party balances consist of the following: March 31, 2017 December 31, 2016 Accounts receivable $ 13.3 $ 10.1 Prepaid expenses 3.6 2.7 Accounts payable (1) 5.7 5.2 Deferred revenue 14.2 7.9 Accrued liabilities (2) 6.2 5.1 Debt payable (3) 685.3 686.0 Lease liability – related party 24.7 24.9 (1) Accounts payable reflects amounts owed to SPLC for reimbursement of third-party expenses incurred by SPLC for our benefit. (2) As of March 31, 2017, accrued liabilities reflects $ 2.9 million accrued interest, $ 1.4 million fuel accrual and $ 1.9 million other accrued liabilities. As of December 31, 2016, accrued liabilities reflects $ 2.6 million accrued interest, $ 1.6 million fuel accrual and $ 0.9 million other accrued liabilities. (3) Debt payable reflects borrowings outstanding after taking into account unamortized debt issuance costs of $1.6 million and $0.9 million as of March 31, 2017 and December 31, 2016 , respectively. Related Party Credit Facilities We have entered into three credit facilities with Shell Treasury Centre (West) Inc. (“STCW”), an affiliate of Shell: the Five Year Revolver, the Five Year Fixed Facility and the 364 -Day Revolver. Zydeco has also entered into the Zydeco Revolver with STCW. For definitions and additional information regarding these credit facilities, see Note 6—Related Party Debt . Related Party Revenues and Expenses We provide crude oil transportation and storage services to related parties under long-term contracts. We entered into these contracts in the normal course of our business and the services are based on terms consistent with those provided to third parties. Our transportation services revenue from related parties was $21.0 million and $23.3 million for the three months ended March 31, 2017 and 2016, respectively. Revenues related to storage services from related parties were $1.9 million and $2.1 million for the three months ended March 31, 2017 and 2016, respectively. During the three months ended March 31, 2017 and 2016, we converted excess allowance oil to cash through sales to affiliates of Shell and recognized a gain of $0.3 million and a loss of less than $0.1 million , respectively, from such sales in Operations and maintenance expense. During the three months ended March 31, 2017 , Zydeco, Bengal, Odyssey, Mars, Poseidon, Proteus, Endymion, Colonial, Explorer and Cleopatra paid cash distributions to us of $91.0 million , of which $39.8 million related to Zydeco. During the three months ended March 31, 2016 , Zydeco, Bengal, Mars, Poseidon and Colonial paid cash distributions to us of $49.7 million , of which $20.6 million related to Zydeco. For a discussion of services performed by SPLC and Shell on our behalf, see Note 1—Description of Business and Basis of Presentation—Basis of Presentation . During the three months ended March 31, 2017 and 2016, we were allocated $1.9 million and $1.3 million , respectively, of indirect general corporate expenses incurred by SPLC and Shell which are included within general and administrative expenses in the condensed consolidated statements of income. Beginning July 1, 2014, Zydeco entered into an operating and management agreement (the “Management Agreement”) with SPLC under which SPLC provides general management and administrative services to us. We no longer receive allocated corporate expenses from SPLC or Shell. We will continue to receive direct and allocated field and regional expenses, including payroll expenses not covered under the Management Agreement. In addition, beginning October 1, 2015, Pecten entered into an operating and management agreement under which we receive direct and allocated field and regional expenses from SPLC. These expenses are primarily allocated to us on the basis of headcount, labor or other measure. These expense allocations have been determined on a basis that both SPLC and we consider to be a reasonable reflection of the utilization of services provided or the benefit received by us during the periods presented. For a discussion of these agreements and other agreements between Pecten and SPLC, see Note 4—Related Party Transactions in the Notes to Consolidated Financial Statements of our 2016 Annual Report. A portion of our insurance coverage is provided by Shell with the remaining coverage by third-party insurers. The related party portion of insurance expense for the three months ended March 31, 2017 and 2016 was $1.7 million and $0.9 million , respectively. The following table shows related party expenses, including personnel costs described above, incurred by Shell and SPLC on our behalf that are reflected in the accompanying condensed consolidated statements of income for the indicated periods: Three Months Ended March 31, 2017 2016 Operations and maintenance - related parties $ 8.5 $ 5.4 General and administrative - related parties (1) 6.4 5.7 (1) For the three months ended March 31, 2017 we incurred $2.0 million under the Management Agreement and $2.1 million under the Omnibus Agreement for the general and administrative fee. For the three months ended March 31, 2016 we incurred $1.9 million under the Management Agreement and $2.1 million under the Omnibus Agreement for the general and administrative fee. Pension and Retirement Savings Plans Employees who directly or indirectly support our operations participate in the pension, postretirement health and life insurance, and defined contribution benefit plans sponsored by Shell, which include other Shell subsidiaries. Our share of pension and postretirement health and life insurance costs for the three months ended March 31, 2017 and 2016 were $0.8 million and $0.6 million, respectively. Our share of defined contribution benefit plan costs for both the three months ended March 31, 2017 and 2016 were $0.3 million . Pension and defined contribution benefit plan expenses are included in either general and administrative expenses or operations and maintenance expenses in the accompanying condensed consolidated statements of income, depending on the nature of the employee’s role in our operations. Equity and Cost Method Investments We have equity and cost method investments in entities, including Odyssey, Mars, Colonial and Explorer in which Shell also owns interests. In some cases we may be required to make capital contributions or other payments to these entities. See Note 3 – Equity Method Investments for additional details. Reimbursements from Our General Partner During the three months ended March 31, 2017, we filed claims for reimbursement from our Parent for our proportionate share of Zydeco directional drill project costs and expenses of $6.4 million . During the three months ended March 31, 2016, we received reimbursement from our Parent for our proportionate share of Zydeco directional drill costs and expenses of $0.1 million .

Equity Method Investments

Equity Method Investments	3 Months Ended
	Mar. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	Equity Method Investments Equity investments in affiliates comprise the following as of the dates indicated: March 31, 2017 December 31, 2016 Ownership Investment Amount Ownership Investment Amount Bengal 50.0% $ 76.7 50.0% $ 76.1 Odyssey 49.0% 3.1 49.0% 3.0 Mars 48.6% 128.4 48.6% 130.2 Poseidon 36.0% 9.9 36.0% 13.2 Proteus 10.0% 18.3 10.0% 19.1 Endymion 10.0% 20.4 10.0% 20.8 $ 256.8 $ 262.4 Unamortized differences in the basis of the initial investments and our interest in the separate net assets within the financial statements of the investees are amortized into net income over the remaining useful lives of the underlying assets. As of March 31, 2017 and December 31, 2016, the unamortized basis differences included in our equity investments are $29.8 million and $30.9 million , respectively. The net amortization expense was $0.7 million and $0.3 million for the three months ended March 31, 2017 and 2016, respectively. Our equity investments in affiliates balance was affected by the following during the periods indicated: Three Months Ended March 31, 2017 Distributions Received Income from Equity Investments Purchase Price Adjustment Bengal $ 4.7 $ 5.3 $ — Odyssey 4.2 4.3 — Mars 23.3 21.5 — Poseidon 10.1 6.8 — Proteus 0.9 0.4 0.3 Endymion 0.7 0.4 0.1 $ 43.9 $ 38.7 $ 0.4 Three Months Ended March 31, 2016 Distributions Received Income from Equity Investments Bengal $ 6.3 $ 5.4 Mars 9.9 10.9 Poseidon 10.1 6.9 $ 26.3 $ 23.2 The following tables present aggregated selected unaudited income statement data for our equity method investments (on a 100% basis): Three Months Ended March 31, 2017 Total Revenues Total Operating Expenses Operating Income Net Income Statements of Income Bengal $ 17.8 $ 7.2 $ 10.6 $ 10.6 Odyssey 9.8 1.0 8.8 8.8 Mars 64.9 19.9 45.0 45.0 Poseidon 28.9 8.1 20.8 19.4 Proteus 7.9 3.1 4.8 4.5 Endymion 8.6 3.1 5.5 5.2 Three Months Ended March 31, 2016 Total Revenues Total Operating Expenses Operating Income Net Income Statements of Income Bengal $ 17.4 $ 6.4 $ 11.0 $ 11.0 Mars 57.3 18.5 38.8 38.8 Poseidon 27.4 6.6 20.8 19.7 The difference between operating income and net income represents interest expense or interest income.

Property, Plant and Equipment

Property, Plant and Equipment	3 Months Ended
	Mar. 31, 2017
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, Plant and Equipment Property, plant and equipment consist of the following as of the dates indicated: Depreciable Life March 31, 2017 December 31, 2016 Land — $ 1.4 $ 1.4 Building and improvements 10 - 40 years 20.7 20.2 Pipeline and equipment (1) 10 - 30 years 591.4 589.7 Other 5 - 25 years 6.7 6.0 620.2 617.3 Accumulated depreciation and amortization (2) (245.7 ) (239.5 ) 374.5 377.8 Construction in progress 29.3 20.2 Property, plant and equipment, net $ 403.8 $ 398.0 (1) As of March 31, 2017 and December 31, 2016, includes cost of $22.8 million related to assets under capital lease. (2) As of March 31, 2017 and December 31, 2016, includes accumulated depreciation of $1.9 million and $1.6 million related to assets under capital lease, respectively. Depreciation and amortization expense on property, plant and equipment for the three months ended March 31, 2017 and 2016 was $6.2 million and $5.9 million , respectively, and is included in cost and expenses in the accompanying condensed consolidated statements of income. Depreciation and amortization expense on property, plant and equipment includes amounts pertaining to assets under capital lease.

Accrued Liabilities - Third Par

Accrued Liabilities - Third Parties	3 Months Ended
	Mar. 31, 2017
Payables and Accruals [Abstract]
Accrued Liabilities - Third Parties	Accrued Liabilities - Third Parties Accrued liabilities - third parties consist of the following as of the dates indicated: March 31, 2017 December 31, 2016 Transportation, project engineering $ 9.5 $ 3.5 Property taxes 2.1 0.6 Professional fees 0.4 0.3 Other accrued liabilities 0.7 1.2 Accrued liabilities - third parties $ 12.7 $ 5.6 For a discussion of accrued liabilities - related parties, see Note 2—Related Party Transactions .

Related Party Debt

Related Party Debt	3 Months Ended
	Mar. 31, 2017
Debt Disclosure [Abstract]
Related Party Debt	Related Party Debt Consolidated related party debt obligations comprise the following as of the dates indicated: March 31, 2017 December 31, 2016 Five Year Fixed Facility, fixed rate, due March 1, 2022 (1) $ — $ — Five Year Revolver, variable rate, due October 31, 2019 (2) 686.9 686.9 Zydeco Revolver, variable rate, due August 6, 2019 (3) — — 364-Day Revolver, variable rate, expired March 1, 2017 (4) — — Unamortized debt issuance costs (1.6 ) (0.9 ) Debt payable – related party $ 685.3 $ 686.0 (1) As of March 31, 2017 , the entire $600.0 million capacity was available under the Five Year Fixed Facility. (2) As of March 31, 2017 , availability under the $760.0 million Five Year Revolver was $73.1 million . (3) As of March 31, 2017 , the entire $30.0 million capacity was available under the Zydeco Revolver. (4) As of March 31, 2017 , the 364 -Day Revolver has expired. For three months ended March 31, 2017 and 2016 , interest and fee expenses associated with our borrowings were approximately $4.0 million and $2.1 million , respectively. On March 29, 2016, we used cash on hand and net proceeds from sales of common units to third parties to repay $ 272.6 million of borrowings outstanding under the Five Year Revolver (as defined below) and all $ 137.4 million of borrowings outstanding under the 364 -Day Revolver (as defined below). There were no additional borrowings or repayments during the quarter ended March 31, 2017. Credit Facility Agreements Five Year Fixed Facility On March 1, 2017 we entered into a Loan Facility Agreement with STCW with a borrowing capacity of $600.0 million (the “ Five Year Fixed Facility”). The Five Year Fixed Facility provides for covenants such as restricting additional indebtedness above certain levels for debt not loaned by STCW, requiring pari passu ranking with any new indebtedness, restrictions on creating security over the assets other than agreed by STCW and contains customary events of default, such as nonpayment of principal when due, nonpayment of interest, fees or other amounts, violation of covenants, we cease to be controlled directly or indirectly by Shell, and cross-payment default (due to indebtedness in excess of $100.0 million ). We may not repay or prepay amounts borrowed without the consent of the lender and amounts repaid or prepaid may not be re-borrowed. We incurred an issuance fee of $0.7 million , which was paid on March 7, 2017. The Five Year Fixed Facility bears a fixed interest rate of 3.23% per annum. The Five Year Fixed Facility matures on March 1, 2022. Five Year Revolver On November 3, 2014, we entered into a five year revolving credit facility (the " Five Year Revolver") with STCW with an initial borrowing capacity of $300.0 million . On May 12, 2015, we amended and restated the Five Year Revolver to increase the borrowing capacity amount to $400.0 million and on September 27, 2016, we further amended and restated the Five Year Revolver to increase the amount of the facility to $760.0 million . In connection with the latest amendment and restatement of the Five Year Revolver, we paid an issuance fee of $0.6 million . The Five Year Revolver, as amended and restated, provides for covenants such as restricting additional indebtedness above certain levels and requiring pari passu ranking with any new indebtedness, and contains customary events of default, such as nonpayment of principal when due, nonpayment of interest, fees or other amounts, violation of covenants, and cross-payment default (due to indebtedness in excess of $100.0 million ). Additionally, the Five Year Revolver provides that loans advanced under the facility can have a term ending on or before its maturity date. Borrowings under the Five Year Revolver bear interest at the three-month LIBOR rate plus a margin. For the three months ended March 31, 2017, the weighted average interest rate for the Five Year Revolver was 2.3% . The Five Year Revolver also provides for customary fees, including administrative agent fees and commitment fees. Commitment fees began to accrue beginning on the date we entered into the Revolver agreement. The Five Year Revolver matures on October 31, 2019 . 364 -Day Revolver On June 29, 2015, in connection with the acquisition done in July 2015, we entered into a second revolving credit facility (the “ 364 -Day Revolver”) with STCW as lender with an initial borrowing capacity of $100.0 million and on November 11, 2015, we amended and restated the 364 -Day Revolver to increase the borrowing capacity amount to $180.0 million . The 364 -Day Revolver expired as of March 1, 2017. Zydeco Revolving Credit Facility Agreement On August 6, 2014, Zydeco entered into a senior unsecured revolving credit facility agreement with STCW (the “Zydeco Revolver”). The facility has a borrowing capacity of $30.0 million . Loans advanced under the agreement have up to a six -month term. The credit agreement governing the Zydeco Revolver provides for covenants such as requiring pari passu ranking with any new indebtedness and contains customary events of default, such as nonpayment of principal when due, nonpayment of interest, fees or other amounts, violation of covenants, and cross-payment default (due to indebtedness in excess of $100.0 million ). Borrowings under the credit facility bear interest at the three-month LIBOR rate plus a margin. As of March 31, 2017, the interest rate for the Zydeco Revolver was 2.6% . The Zydeco Revolver also requires payment of customary fees, including issuance and commitment fees. The Zydeco Revolver matures on August 6, 2019. Any breach of covenants included in our debt agreements which could result in our related party lender demanding payment of the unpaid principal and interest balances will have a material adverse effect upon us and would likely require us to seek to renegotiate these debt arrangements with our related party lender and/or obtain new financing from other sources. As of March 31, 2017 , we were in compliance with the covenants contained in the Five Year Fixed Facility and the Five Year Revolver, and Zydeco was in compliance with the covenants contained in the Zydeco Revolver.

Equity

Equity	3 Months Ended
	Mar. 31, 2017
Equity [Abstract]
Equity	Equity At-the-Market Program On March 2, 2016, we commenced an “at-the-market” equity distribution program pursuant to which we may issue and sell common units for up to $300.0 million in gross proceeds. This program is registered with the SEC on an effective registration statement on Form S-3. On February 28, 2017, we entered into an Amended and Restated Equity Distribution Agreement with the Managers named therein. During the quarter ended March 31, 2016, we completed the sale of 750,000 common units under this program for $25.4 million net proceeds ( $25.5 million gross proceeds, or an average price of $34.00 per common unit, less $0.1 million of transaction fees). In connection with the issuance of the common units, we issued 15,307 general partner units to our general partner for $0.5 million in order to maintain its 2.0% general partner interest in us. We used the net proceeds from these sales of common units and from our general partner’s proportionate capital contribution to repay borrowings outstanding under the Five Year Revolver and the 364 -Day Revolver and for general partnership purposes. During the quarter ended March 31, 2017 , we did not sell any common units under this program. Public Offering On March 29, 2016, we completed the sale of 12,650,000 common units in a registered public offering (the "March 2016 Offering") for $395.1 million net proceeds ( $401.6 million gross proceeds, or $31.75 per common unit, less $6.3 million of underwriter's fees and $0.2 million of transaction fees). In connection with the issuance of the common units, we issued 258,163 general partner units to our general partner for $8.2 million in order to maintain its 2.0% general partner interest in us. We used the net proceeds from the March 2016 Offering and from our general partner’s proportionate capital contribution to repay borrowings outstanding under the Five Year Revolver and the 364 -Day Revolver and for general partnership purposes. Units Outstanding As of March 31, 2017 , we had 177,317,444 common units outstanding, of which 88,367,308 were publicly owned. SPLC owned 88,950,136 common units, representing an aggregate 49.2% limited partner interest in us, all of the incentive distribution rights, and 3,618,723 general partner units, representing a 2.0% general partner interest in us. The changes in the number of units outstanding from December 31, 2016 through March 31, 2017 are as follows: Public SPLC SPLC General (in units) Common Common Subordinated Partner Total Balance as of December 31, 2016 88,367,308 21,475,068 67,475,068 3,618,723 180,936,167 Expiration of subordination period — 67,475,068 (67,475,068 ) — — Balance as of March 31, 2017 88,367,308 88,950,136 — 3,618,723 180,936,167 Expiration of Subordination Period On February 15, 2017, all of the subordinated units converted into common units following the payment of the cash distribution for the fourth quarter of 2016. Each of our 67,475,068 outstanding subordinated units converted into one common unit. As of March 31, 2017, and for any distribution of available cash in the 2017 periods, the converted units will participate pro rata with the other common units in distributions of available cash. The conversion of the subordinated units does not impact the amount of cash distributions paid by us or the total number of outstanding units. The allocation of net income and cash distributions during the period were effected in accordance with terms of the partnership agreement. Distributions to our Unitholders The following table details the distributions declared and/or paid for the periods presented: Date Paid or Public SPLC SPLC General Partner Distributions to be Paid Three Months Ended Common Common Subordinated IDR's 2% Total (in millions, except per unit amounts) February 11, 2016 December 31, 2015 $ 13.8 $ 4.7 $ 14.9 $ 1.2 $ 0.7 $ 35.3 $ 0.22000 May 12, 2016 March 31, 2016 17.9 5.1 15.8 2.0 0.9 41.7 0.23500 August 12, 2016 June 30, 2016 22.0 5.4 16.9 3.7 1.0 49.0 0.25000 November 14, 2016 September 30, 2016 23.3 5.7 17.8 6.0 1.1 53.9 0.26375 February 14, 2017 December 31, 2016 24.5 5.9 18.7 8.3 1.2 58.6 0.27700 May 12, 2017 March 31, 2017 (1) 25.7 25.9 — 10.7 1.3 63.6 0.29100 (1) For more information see Note 11 — Subsequent Events . Distributions to Noncontrolling Interest Distributions to SPLC for its noncontrolling interest in Zydeco were $3.2 million and $12.4 million , respectively, for the three months ended March 31, 2017 and 2016. See Note 2—Related Party Transactions for additional details.

Net Income Per Limited Partner

Net Income Per Limited Partner Unit	3 Months Ended
	Mar. 31, 2017
Partners' Capital Notes [Abstract]
Net Income Per Limited Partner Unit	Net Income Per Limited Partner Unit Net income per unit applicable to common limited partner units, and to subordinated limited partner units in periods prior to the expiration of the subordination period, is computed by dividing the respective limited partners’ interest in net income attributable to the Partnership for the period by the weighted average number of common units and subordinated units, respectively, outstanding for the period. Because we have more than one class of participating securities, we use the two-class method when calculating the net income per unit applicable to limited partners. The classes of participating securities include common units, subordinated units, general partner units and incentive distribution rights. Basic and diluted net income per unit are the same because we do not have any potentially dilutive units outstanding for the period presented. The following tables show the allocation of net income attributable to the Partnership to arrive at net income per limited partner unit: Three Months Ended 2017 2016 Net income $ 73.0 $ 68.0 Less: Net income attributable to noncontrolling interests 2.2 12.7 Net income attributable to the Partnership 70.8 55.3 Less: General Partner's distribution declared 12.0 2.9 Limited Partners' distribution declared on common units 51.6 23.0 Limited Partners' distribution declared on subordinated units — 15.8 Income in excess of distributions $ 7.2 $ 13.6 Three Months Ended March 31, 2017 General Limited Partners' Partner Common Units Total (in millions of dollars, except per unit data) Distributions declared $ 12.0 $ 51.6 $ 63.6 Income in excess of distributions 0.1 7.1 7.2 Net income attributable to the Partnership $ 12.1 $ 58.7 $ 70.8 Weighted average units outstanding (in millions) (1) : Basic and diluted 177.3 Net income per Limited Partner Unit (in dollars): Basic and diluted $ 0.33 (1) The subordinated units converted into common units on February 15, 2017, and were considered outstanding common units for the entire period with respect to the weighted average number of units outstanding. Three Months Ended March 31, 2016 General Limited Partners' Limited Partners' Partner Common Units Subordinated Units Total (in millions of dollars, except per unit data) Distributions declared $ 2.9 $ 23.0 $ 15.8 $ 41.7 Distributions in excess of income 0.2 7.5 5.9 13.6 Net income attributable to the Partnership $ 3.1 $ 30.5 $ 21.7 $ 55.3 Weighted average units outstanding (in millions): Basic and diluted 84.9 67.5 Net income per Limited Partner Unit (in dollars): Basic and diluted $ 0.36 $ 0.32

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes We are not a taxable entity for U.S. federal income tax purposes or for the majority of states that impose an income tax. Taxes on our net income are generally borne by our partners through the allocation of taxable income. Our income tax expense results from partnership activity in the state of Texas, as conducted by Zydeco. Income tax expense for the three months ended March 31, 2017 and 2016 were immaterial.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Environmental Matters We are subject to federal, state, and local environmental laws and regulations. We routinely conduct reviews of potential environmental issues and claims that could impact our assets or operations. These reviews assist us in identifying environmental issues and estimating the costs and timing of remediation efforts. In making environmental liability estimations, we consider the material effect of environmental compliance, pending legal actions against us and potential third-party liability claims. Often, as the remediation evaluation and effort progresses, additional information is obtained, requiring revisions to estimated costs. These revisions are reflected in our income in the period in which they are probable and reasonably estimable. As of March 31, 2017 , and December 31, 2016 , we did not have any material accrued liabilities associated with environmental clean-up costs. Legal Proceedings We are named defendants in lawsuits and governmental proceedings that arise in the ordinary course of business. For each of our outstanding legal matters, we evaluate the merits of the case, our exposure to the matter, possible legal or settlement strategies and the likelihood of an unfavorable outcome. While there are still uncertainties related to the ultimate costs we may incur, based upon our evaluation and experience to date, we do not expect that the ultimate resolution of these matters will have a material adverse effect on our financial position, operating results, or cash flows. Effective July 31, 2014, a rate case was filed against Zydeco with the FERC. The rate case was resolved by a settlement approved by FERC which established maximum rates for uncommitted (or non-contract) shippers effective December 1, 2015. The settlement also provided for rate refunds for shippers of the difference between the higher pre-settlement uncommitted (or non-contract) rates and the lower settlement rates for the period from July 31, 2014 to November 30, 2015 (plus interest). All expenses related to the FERC rate case were recognized prior to 2016. The shippers' settlements were paid in January 2016 and all related indemnifications were received. Indemnification Under our Omnibus Agreement, certain environmental liabilities, tax liabilities, litigation and other matters attributable to the ownership or operation of our assets prior to the IPO are indemnified by SPLC. For more information, see Note 2 - Related Party Transactions. Minimum Throughput On September 1, 2016, the in-service date of the capital lease for the Port Neches storage tanks, a joint tariff agreement with a third party became effective and requires monthly payments of approximately $0.4 million . The tariff will be analyzed annually and updated based on the FERC indexing adjustment to rates effective July 1 of each year. The initial term of the agreement is ten years with automatic one year renewal terms with the option to cancel prior to each renewal period.

Subsequent Events

Subsequent Events	3 Months Ended
	Mar. 31, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events We have evaluated events that have occurred after March 31, 2017 , through the issuance of these condensed consolidated financial statements. Any material subsequent events that occurred during this time have been properly recognized or disclosed in the consolidated financial statements and accompanying notes. Distribution On April 19, 2017 , the Board declared a cash distribution of $0.29100 per limited partner unit for the three months ended March 31, 2017 . The distribution will be paid on May 12, 2017 to unitholders of record as of May 1, 2017 . April 2017 Divestiture On April 28, 2017, we entered into a transaction to divest a small segment of our Zydeco pipeline system (the “April 2017 Divestiture”) to a related party as part of the Motiva JV separation. We determined that the 5.5-mile pipeline segment that connects Port Neches to the Port Arthur Refinery is not strategic to the overall Zydeco pipeline system. The total transaction price was $21.0 million . May 2017 Acquisition On May 4, 2017, we entered into a purchase and sale agreement with Shell Chemical LP (“Shell Chemical”), Shell GOM Pipeline Company LP and SPLC to acquire a 100% interest in the following assets for $630.0 million : (1) a network of approximately 100-miles of pipeline connecting Shell Chemical sites to multiple refineries along the Gulf Coast; (2) approximately 128-miles of pipeline aggregating volumes from five pipelines and delivering volumes to key onshore markets, which we refer to as the Delta Pipeline; and (3) a pipeline system of approximately 75-miles located in the Eastern Gulf of Mexico serving as a host to eight different subsea fields and connecting to the Delta Pipeline, which we refer to as the Na Kika Pipeline (collectively, the “May 2017 Acquisition”). We expect to complete the May 2017 Acquisition on or around May 10, 2017, subject to customary closing conditions. We expect to fund the May 2017 Acquisition with a combination of borrowings under our credit facilities and cash on hand.

Description of Business and B18

Description of Business and Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Description of Business We are a fee-based, growth-oriented master limited partnership formed by Shell to own, operate, develop and acquire pipelines and other midstream assets. Our assets consist of interests in entities that own crude oil and refined products pipelines serving as key infrastructure to transport onshore and offshore crude oil production to Gulf Coast and Midwest refining markets and to deliver refined products from those markets to major demand centers. As of March 31, 2017 , we own interests in seven crude oil pipeline systems, three refined products systems, one natural gas gathering pipeline system and a crude tank storage and terminal system. The crude oil pipeline systems include the Auger Pipeline System (“Auger”), held by Pecten Midstream LLC (“Pecten”), Zydeco Pipeline Company LLC (“Zydeco”), Odyssey Pipeline LLC (“Odyssey”), Mars Oil Pipeline Company (“Mars”), Poseidon Oil Pipeline Company LLC (“Poseidon”), Proteus Oil Pipeline Company, LLC (“Proteus”), and Endymion Oil Pipeline Company, LLC (“Endymion”), and are strategically located along the Texas and Louisiana Gulf Coast and in the Gulf of Mexico. These systems link major onshore and offshore production areas with key refining markets. The refined products pipeline systems, which are held by Bengal Pipeline Company LLC (“Bengal”) and Colonial Pipeline Company (“Colonial”), connect Gulf Coast and southeastern U.S. refineries to major demand centers from Alabama to New York, and Explorer Pipeline Company (“Explorer”) which serves more than 70 major cities in 16 states from the Gulf Coast to the Midwest. The natural gas pipeline system, Cleopatra Gas Gathering Company, LLC (“Cleopatra”), brings Gulf of Mexico gas production to the market hub at Ship Shoal 332. The crude storage terminal, Lockport Terminal (“Lockport”), is located southwest of Chicago and serves Midwest refineries. As of March 31, 2017 , we own a 100% interest in Pecten, a 92.5% interest in Zydeco, a 50.0% interest in Bengal, a 49.0% interest in Odyssey, a 48.6% interest in Mars, a 36.0% interest in Poseidon, a 10.0% interest in Proteus, a 10.0% interest in Endymion, a 6.0% interest in Colonial, a 2.62% interest in Explorer and a 1.0% interest in Cleopatra. Each of Pecten and Zydeco is consolidated within our condensed consolidated financial statements as a subsidiary. The 7.5% ownership interest in Zydeco retained by SPLC is reflected as noncontrolling interest in our condensed consolidated financial statements. We account for each of our investments in Bengal, Odyssey, Mars, Poseidon, Proteus and Endymion using the equity method of accounting, and we account for each of our investments in Colonial, Explorer and Cleopatra using the cost method of accounting. We generate a substantial portion of our revenue under long-term agreements by charging fees for the transportation and storage of crude oil and refined products through our pipelines and storage tanks and from income from our equity and cost method investments. Our operations consist of one reportable segment.
Basis of Presentation	Basis of Presentation Our condensed consolidated financial statements include all majority owned and non-majority owned subsidiaries required to be consolidated under generally accepted accounting principles in the United States (“GAAP”). Our reporting currency is U.S. dollars, and all references to dollars are U.S. dollars. The accompanying unaudited condensed consolidated financial statements and related notes have been prepared in accordance with GAAP for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and notes required by GAAP for complete annual financial statements. The year-end condensed consolidated balance sheet data was derived from audited financial statements, but does not include all disclosures required by GAAP. During interim periods, we follow the accounting policies disclosed in our Annual Report on Form 10-K for the year ended December 31, 2016 (our “2016 Annual Report”), filed with the United States Securities and Exchange Commission (“SEC”). The unaudited condensed consolidated financial statements for the three months ended March 31, 2017 and 2016 include all adjustments we believe are necessary for a fair statement of the results for the interim periods. These adjustments are of a normal recurring nature unless otherwise disclosed. Operating results for the three months ended March 31, 2017 are not necessarily indicative of the results that may be expected for the full year. These unaudited condensed consolidated financial statements and other information included in this Quarterly Report on Form 10-Q should be read in conjunction with our consolidated financial statements and notes thereto included in our 2016 Annual Report.
Recently Adopted and Recent Accounting Pronouncements	Recently Adopted Accounting Pronouncements In October 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-17 to Topic 810, Consolidation, making changes on how a reporting entity should treat indirect interests in an entity held through related parties that are under common control with the reporting entity when determining whether it is the primary beneficiary of a variable interest entity. The update was effective for us as of January 1, 2017. The adoption of this update did not have a material impact on our financial statements. In March 2016, the FASB issued ASU 2016-07 to Topic 323, Investments - Equity Method and Joint Ventures, to eliminate the need for an entity to retroactively adopt the equity method of accounting when an investment becomes qualified for the use of the equity method of accounting due to an increase in level of ownership or degree of influence. The update was effective for us as of January 1, 2017. The adoption of this update did not have a material impact on our financial statements. Recent Accounting Pronouncements In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers, which will supersede nearly all existing revenue recognition guidance under GAAP. The update's core principle is that a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. The update is effective for fiscal years and interim periods within those fiscal years beginning after December 15, 2017. The update allows for either “full retrospective” adoption, meaning the standard is applied to all of the periods presented, or “modified retrospective” adoption, meaning the standard is applied only to the most current period presented in the financial statements. We continue to evaluate our existing revenue recognition policies to determine whether any contracts in the scope of the guidance will be affected by the new requirements. We have not yet selected a transition method nor have we determined the effect of the update on our consolidated results of operations, financial position or cash flows. For additional information on accounting pronouncements issued prior to March 2017, refer to Note 2—Summary of Significant Accounting Policies in the Notes to Consolidated Financial Statements of our 2016 Annual Report.

Related Party Transactions (Tab

Related Party Transactions (Tables)	3 Months Ended
	Mar. 31, 2017
Related Party Transactions [Abstract]
Schedule of Other Related Party Balances	Other related party balances consist of the following: March 31, 2017 December 31, 2016 Accounts receivable $ 13.3 $ 10.1 Prepaid expenses 3.6 2.7 Accounts payable (1) 5.7 5.2 Deferred revenue 14.2 7.9 Accrued liabilities (2) 6.2 5.1 Debt payable (3) 685.3 686.0 Lease liability – related party 24.7 24.9 (1) Accounts payable reflects amounts owed to SPLC for reimbursement of third-party expenses incurred by SPLC for our benefit. (2) As of March 31, 2017, accrued liabilities reflects $ 2.9 million accrued interest, $ 1.4 million fuel accrual and $ 1.9 million other accrued liabilities. As of December 31, 2016, accrued liabilities reflects $ 2.6 million accrued interest, $ 1.6 million fuel accrual and $ 0.9 million other accrued liabilities. (3) Debt payable reflects borrowings outstanding after taking into account unamortized debt issuance costs of $1.6 million and $0.9 million as of March 31, 2017 and December 31, 2016 , respectively.
Schedule Of Related Party Expenses Including Personnel Costs	The following table shows related party expenses, including personnel costs described above, incurred by Shell and SPLC on our behalf that are reflected in the accompanying condensed consolidated statements of income for the indicated periods: Three Months Ended March 31, 2017 2016 Operations and maintenance - related parties $ 8.5 $ 5.4 General and administrative - related parties (1) 6.4 5.7 (1) For the three months ended March 31, 2017 we incurred $2.0 million under the Management Agreement and $2.1 million under the Omnibus Agreement for the general and administrative fee. For the three months ended March 31, 2016 we incurred $1.9 million under the Management Agreement and $2.1 million under the Omnibus Agreement for the general and administrative fee.

Equity Method Investments (Tabl

Equity Method Investments (Tables)	3 Months Ended
	Mar. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Equity Investments in Affiliates	Equity investments in affiliates comprise the following as of the dates indicated: March 31, 2017 December 31, 2016 Ownership Investment Amount Ownership Investment Amount Bengal 50.0% $ 76.7 50.0% $ 76.1 Odyssey 49.0% 3.1 49.0% 3.0 Mars 48.6% 128.4 48.6% 130.2 Poseidon 36.0% 9.9 36.0% 13.2 Proteus 10.0% 18.3 10.0% 19.1 Endymion 10.0% 20.4 10.0% 20.8 $ 256.8 $ 262.4
Schedule of Equity Investments in Affiliates Balance Affected	Our equity investments in affiliates balance was affected by the following during the periods indicated: Three Months Ended March 31, 2017 Distributions Received Income from Equity Investments Purchase Price Adjustment Bengal $ 4.7 $ 5.3 $ — Odyssey 4.2 4.3 — Mars 23.3 21.5 — Poseidon 10.1 6.8 — Proteus 0.9 0.4 0.3 Endymion 0.7 0.4 0.1 $ 43.9 $ 38.7 $ 0.4 Three Months Ended March 31, 2016 Distributions Received Income from Equity Investments Bengal $ 6.3 $ 5.4 Mars 9.9 10.9 Poseidon 10.1 6.9 $ 26.3 $ 23.2
Summary of Income Statement Data for Equity Method Investments	The following tables present aggregated selected unaudited income statement data for our equity method investments (on a 100% basis): Three Months Ended March 31, 2017 Total Revenues Total Operating Expenses Operating Income Net Income Statements of Income Bengal $ 17.8 $ 7.2 $ 10.6 $ 10.6 Odyssey 9.8 1.0 8.8 8.8 Mars 64.9 19.9 45.0 45.0 Poseidon 28.9 8.1 20.8 19.4 Proteus 7.9 3.1 4.8 4.5 Endymion 8.6 3.1 5.5 5.2 Three Months Ended March 31, 2016 Total Revenues Total Operating Expenses Operating Income Net Income Statements of Income Bengal $ 17.4 $ 6.4 $ 11.0 $ 11.0 Mars 57.3 18.5 38.8 38.8 Poseidon 27.4 6.6 20.8 19.7

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	3 Months Ended
	Mar. 31, 2017
Property, Plant and Equipment [Abstract]
Components of Property, Plant and Equipment	Property, plant and equipment consist of the following as of the dates indicated: Depreciable Life March 31, 2017 December 31, 2016 Land — $ 1.4 $ 1.4 Building and improvements 10 - 40 years 20.7 20.2 Pipeline and equipment (1) 10 - 30 years 591.4 589.7 Other 5 - 25 years 6.7 6.0 620.2 617.3 Accumulated depreciation and amortization (2) (245.7 ) (239.5 ) 374.5 377.8 Construction in progress 29.3 20.2 Property, plant and equipment, net $ 403.8 $ 398.0 (1) As of March 31, 2017 and December 31, 2016, includes cost of $22.8 million related to assets under capital lease. (2) As of March 31, 2017 and December 31, 2016, includes accumulated depreciation of $1.9 million and $1.6 million related to assets under capital lease, respectively.

Accrued Liabilities - Third P22

Accrued Liabilities - Third Parties (Tables)	3 Months Ended
	Mar. 31, 2017
Payables and Accruals [Abstract]
Schedule of Accrued Liabilities	Accrued liabilities - third parties consist of the following as of the dates indicated: March 31, 2017 December 31, 2016 Transportation, project engineering $ 9.5 $ 3.5 Property taxes 2.1 0.6 Professional fees 0.4 0.3 Other accrued liabilities 0.7 1.2 Accrued liabilities - third parties $ 12.7 $ 5.6

Related Party Debt (Tables)

Related Party Debt (Tables)	3 Months Ended
	Mar. 31, 2017
Debt Disclosure [Abstract]
Schedule of Consolidated Related Party Debt Obligations	Consolidated related party debt obligations comprise the following as of the dates indicated: March 31, 2017 December 31, 2016 Five Year Fixed Facility, fixed rate, due March 1, 2022 (1) $ — $ — Five Year Revolver, variable rate, due October 31, 2019 (2) 686.9 686.9 Zydeco Revolver, variable rate, due August 6, 2019 (3) — — 364-Day Revolver, variable rate, expired March 1, 2017 (4) — — Unamortized debt issuance costs (1.6 ) (0.9 ) Debt payable – related party $ 685.3 $ 686.0 (1) As of March 31, 2017 , the entire $600.0 million capacity was available under the Five Year Fixed Facility. (2) As of March 31, 2017 , availability under the $760.0 million Five Year Revolver was $73.1 million . (3) As of March 31, 2017 , the entire $30.0 million capacity was available under the Zydeco Revolver. (4) As of March 31, 2017 , the 364 -Day Revolver has expired.

Equity (Tables)

Equity (Tables)	3 Months Ended
	Mar. 31, 2017
Equity [Abstract]
Schedule of Number of Units Outstanding	The changes in the number of units outstanding from December 31, 2016 through March 31, 2017 are as follows: Public SPLC SPLC General (in units) Common Common Subordinated Partner Total Balance as of December 31, 2016 88,367,308 21,475,068 67,475,068 3,618,723 180,936,167 Expiration of subordination period — 67,475,068 (67,475,068 ) — — Balance as of March 31, 2017 88,367,308 88,950,136 — 3,618,723 180,936,167
Schedule of Distributions Declared and/or Paid	The following table details the distributions declared and/or paid for the periods presented: Date Paid or Public SPLC SPLC General Partner Distributions to be Paid Three Months Ended Common Common Subordinated IDR's 2% Total (in millions, except per unit amounts) February 11, 2016 December 31, 2015 $ 13.8 $ 4.7 $ 14.9 $ 1.2 $ 0.7 $ 35.3 $ 0.22000 May 12, 2016 March 31, 2016 17.9 5.1 15.8 2.0 0.9 41.7 0.23500 August 12, 2016 June 30, 2016 22.0 5.4 16.9 3.7 1.0 49.0 0.25000 November 14, 2016 September 30, 2016 23.3 5.7 17.8 6.0 1.1 53.9 0.26375 February 14, 2017 December 31, 2016 24.5 5.9 18.7 8.3 1.2 58.6 0.27700 May 12, 2017 March 31, 2017 (1) 25.7 25.9 — 10.7 1.3 63.6 0.29100 (1) For more information see Note 11 — Subsequent Events .

Net Income Per Limited Partne25

Net Income Per Limited Partner Unit (Tables)	3 Months Ended
	Mar. 31, 2017
Partners' Capital Notes [Abstract]
Schedule of Allocation of Net Income to Arrive at Net Income Per Limited Partner Unit	The following tables show the allocation of net income attributable to the Partnership to arrive at net income per limited partner unit: Three Months Ended 2017 2016 Net income $ 73.0 $ 68.0 Less: Net income attributable to noncontrolling interests 2.2 12.7 Net income attributable to the Partnership 70.8 55.3 Less: General Partner's distribution declared 12.0 2.9 Limited Partners' distribution declared on common units 51.6 23.0 Limited Partners' distribution declared on subordinated units — 15.8 Income in excess of distributions $ 7.2 $ 13.6
Schedule of Basic and Diluted Net Income Per Unit	Three Months Ended March 31, 2017 General Limited Partners' Partner Common Units Total (in millions of dollars, except per unit data) Distributions declared $ 12.0 $ 51.6 $ 63.6 Income in excess of distributions 0.1 7.1 7.2 Net income attributable to the Partnership $ 12.1 $ 58.7 $ 70.8 Weighted average units outstanding (in millions) (1) : Basic and diluted 177.3 Net income per Limited Partner Unit (in dollars): Basic and diluted $ 0.33 (1) The subordinated units converted into common units on February 15, 2017, and were considered outstanding common units for the entire period with respect to the weighted average number of units outstanding. Three Months Ended March 31, 2016 General Limited Partners' Limited Partners' Partner Common Units Subordinated Units Total (in millions of dollars, except per unit data) Distributions declared $ 2.9 $ 23.0 $ 15.8 $ 41.7 Distributions in excess of income 0.2 7.5 5.9 13.6 Net income attributable to the Partnership $ 3.1 $ 30.5 $ 21.7 $ 55.3 Weighted average units outstanding (in millions): Basic and diluted 84.9 67.5 Net income per Limited Partner Unit (in dollars): Basic and diluted $ 0.36 $ 0.32

Description of Business and B26

Description of Business and Basis of Presentation (Details)	3 Months Ended
	Mar. 31, 2017statecitysegmentsystem	Dec. 31, 2016	Mar. 31, 2016
Description Of Business And Basis Of Presentation [Line Items]
Number of pipeline systems	7
Number of refined products systems	3
Number of natural gas gathering pipeline systems	1
Number of crude tank storage and terminal systems	1
Number of cities the entity serves | city	70
Number of states the entity serves | state	16
Number of reportable segments | segment	1
Pecten
Description Of Business And Basis Of Presentation [Line Items]
Ownership	100.00%
Zydeco
Description Of Business And Basis Of Presentation [Line Items]
Minority interest ownership percentage by parent	92.50%
Zydeco | SPLC
Description Of Business And Basis Of Presentation [Line Items]
Noncontrolling Interest	7.50%	7.50%	37.50%
Bengal
Description Of Business And Basis Of Presentation [Line Items]
Ownership	50.00%	50.00%
Odyssey
Description Of Business And Basis Of Presentation [Line Items]
Ownership	49.00%	49.00%
Mars
Description Of Business And Basis Of Presentation [Line Items]
Ownership	48.60%	48.60%
Poseidon
Description Of Business And Basis Of Presentation [Line Items]
Ownership	36.00%	36.00%
Proteus
Description Of Business And Basis Of Presentation [Line Items]
Ownership	10.00%	10.00%
Endymion
Description Of Business And Basis Of Presentation [Line Items]
Ownership	10.00%	10.00%
Colonial
Description Of Business And Basis Of Presentation [Line Items]
Cost method investment percentage	6.00%
Explorer
Description Of Business And Basis Of Presentation [Line Items]
Cost method investment percentage	2.62%
Cleopatra
Description Of Business And Basis Of Presentation [Line Items]
Cost method investment percentage	1.00%

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details)	Nov. 03, 2014USD ($)	Mar. 31, 2017USD ($)credit_facility	Mar. 31, 2016USD ($)	Dec. 31, 2016
Related Party Transaction [Line Items]
Indemnification liability deductible amount	$ 500,000
Aggregate liability of SPLC	15,000,000	$ 10,700,000
Statute of limitations expirations, number of days				60 days
Revenue from related parties		22,900,000	$ 25,400,000
Gain (loss) from sale of excess allowance oil		300,000	(100,000)
Transportation Services
Related Party Transaction [Line Items]
Revenue from related parties		21,000,000	23,300,000
Storage Services
Related Party Transaction [Line Items]
Revenue from related parties		1,900,000	2,100,000
SPLC
Related Party Transaction [Line Items]
General and administrative - related parties		1,900,000	1,300,000
General insurance expense		$ 1,700,000	900,000
Shell Treasury Center West Inc
Related Party Transaction [Line Items]
Number of credit facilities | credit_facility		3
Shell Treasury Center West Inc | Five Year Revolver
Related Party Transaction [Line Items]
Debt instrument term		5 years
Shell Treasury Center West Inc | Five Year Fixed Facility
Related Party Transaction [Line Items]
Debt instrument term		5 years
Shell Treasury Center West Inc | 364 Day Revolver
Related Party Transaction [Line Items]
Debt instrument term		364 days		364 days
Zydeco, Mars, Bengal, Poseidon and Colonial
Related Party Transaction [Line Items]
Total distributions to general partners		$ 91,000,000	49,700,000
Shell Pipeline Company L P
Related Party Transaction [Line Items]
Payment of general and administrative fee	$ 8,500,000
Zydeco
Related Party Transaction [Line Items]
Total distributions to general partners		$ 39,800,000	$ 20,600,000
SPLC | Zydeco
Related Party Transaction [Line Items]
Noncontrolling Interest		7.50%	37.50%	7.50%

Related Party Transactions - Sc

Related Party Transactions - Schedule of Other Related Party Balances (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Related Party Transaction [Line Items]
Accounts receivable	$ 13.3	$ 10.1
Prepaid expenses	3.6	2.7
Accounts payable	5.7	5.2
Deferred revenue	14.2	7.9
Accrued liabilities	6.2	5.1
Debt payable – related party	685.3	686
Lease liability – related party	24.7	24.9
Accrued interest, related parties	2.9	2.6
Fuel accrual, related parties	1.4	1.6
Other accrued liabilities, related parties	1.9	0.9
Unamortized debt issuance costs	1.6	0.9
Affiliated Entity
Related Party Transaction [Line Items]
Unamortized debt issuance costs	$ 1.6	$ 0.9

Related Party Transactions - 29

Related Party Transactions - Schedule of Condensed Combined Statement of Operations (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Related Party Transaction [Line Items]
Operations and maintenance – related parties	$ 8.5	$ 5.4
General and administrative – related parties	6.4	5.7
Management Agreement
Related Party Transaction [Line Items]
Payment for general administrative services	2	1.9
Omnibus Agreement
Related Party Transaction [Line Items]
Payment for general administrative services	$ 2.1	$ 2.1

Related Party Transactions - Pe

Related Party Transactions - Pension and Retirement Savings Plans (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Related Party Transactions [Abstract]
Health and life insurance costs	$ 0.8	$ 0.6
Defined contribution benefit plan costs	$ 0.3	$ 0.3

Related Party Transactions - Re

Related Party Transactions - Reimbursements from Our General Partner (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Zydeco
Related Party Transaction [Line Items]
Reimbursement of Zydeco directional drill	$ 6.4	$ 0.1

Equity Method Investments - Sch

Equity Method Investments - Schedule of Equity Investments in Affiliates (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Investment Amount	$ 256.8	$ 262.4
Bengal
Schedule of Equity Method Investments [Line Items]
Ownership	50.00%	50.00%
Investment Amount	$ 76.7	$ 76.1
Odyssey
Schedule of Equity Method Investments [Line Items]
Ownership	49.00%	49.00%
Investment Amount	$ 3.1	$ 3
Mars
Schedule of Equity Method Investments [Line Items]
Ownership	48.60%	48.60%
Investment Amount	$ 128.4	$ 130.2
Poseidon
Schedule of Equity Method Investments [Line Items]
Ownership	36.00%	36.00%
Investment Amount	$ 9.9	$ 13.2
Proteus
Schedule of Equity Method Investments [Line Items]
Ownership	10.00%	10.00%
Investment Amount	$ 18.3	$ 19.1
Endymion
Schedule of Equity Method Investments [Line Items]
Ownership	10.00%	10.00%
Investment Amount	$ 20.4	$ 20.8

Equity Method Investments - Add

Equity Method Investments - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Equity Method Investments and Joint Ventures [Abstract]
Unamortized basis differences included in equity investments	$ 29.8		$ 30.9
Amortization Expense (Income)	$ 0.7	$ 0.3

Equity Method Investments - S34

Equity Method Investments - Schedule of Equity Investments in Affiliates Balance Affected (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Schedule of Equity Method Investments [Line Items]
Distributions Received	$ 43.9	$ 26.3
Income from equity investments	38.7	23.2
Purchase price adjustment	0.4	0
Bengal
Schedule of Equity Method Investments [Line Items]
Distributions Received	4.7	6.3
Income from equity investments	5.3	5.4
Purchase price adjustment	0
Odyssey
Schedule of Equity Method Investments [Line Items]
Distributions Received	4.2
Income from equity investments	4.3
Purchase price adjustment	0
Mars
Schedule of Equity Method Investments [Line Items]
Distributions Received	23.3	9.9
Income from equity investments	21.5	10.9
Purchase price adjustment	0
Poseidon
Schedule of Equity Method Investments [Line Items]
Distributions Received	10.1	10.1
Income from equity investments	6.8	$ 6.9
Purchase price adjustment	0
Proteus
Schedule of Equity Method Investments [Line Items]
Distributions Received	0.9
Income from equity investments	0.4
Purchase price adjustment	0.3
Endymion
Schedule of Equity Method Investments [Line Items]
Distributions Received	0.7
Income from equity investments	0.4
Purchase price adjustment	$ 0.1

Equity Method Investments - Sum

Equity Method Investments - Summary of Income Statement Data for Equity Method Investments (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Bengal
Schedule of Equity Method Investments [Line Items]
Total Revenues	$ 17.8	$ 17.4
Total Operating Expenses	7.2	6.4
Operating Income	10.6	11
Net Income	10.6	11
Odyssey
Schedule of Equity Method Investments [Line Items]
Total Revenues	9.8
Total Operating Expenses	1
Operating Income	8.8
Net Income	8.8
Mars
Schedule of Equity Method Investments [Line Items]
Total Revenues	64.9	57.3
Total Operating Expenses	19.9	18.5
Operating Income	45	38.8
Net Income	45	38.8
Poseidon
Schedule of Equity Method Investments [Line Items]
Total Revenues	28.9	27.4
Total Operating Expenses	8.1	6.6
Operating Income	20.8	20.8
Net Income	19.4	$ 19.7
Proteus
Schedule of Equity Method Investments [Line Items]
Total Revenues	7.9
Total Operating Expenses	3.1
Operating Income	4.8
Net Income	4.5
Endymion
Schedule of Equity Method Investments [Line Items]
Total Revenues	8.6
Total Operating Expenses	3.1
Operating Income	5.5
Net Income	$ 5.2

Property, Plant and Equipment -

Property, Plant and Equipment - Components of Property, Plant and Equipment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Property Plant And Equipment [Line Items]
Land	$ 1.4	$ 1.4
Building and improvements	20.7	20.2
Pipeline and equipment	591.4	589.7
Other	6.7	6
Property, plant and equipment, gross	620.2	617.3
Accumulated depreciation	(245.7)	(239.5)
Property plant and equipment excluding construction in progress	374.5	377.8
Construction in progress	29.3	20.2
Property, plant and equipment, net	403.8	398
Costs related to assets under capital lease	22.8	22.8
Accumulated depreciation on assets under capital lease	$ 1.9	$ 1.6
Building and Improvements | Minimum
Property Plant And Equipment [Line Items]
Property, plant and equipment, depreciable life	10 years
Building and Improvements | Maximum
Property Plant And Equipment [Line Items]
Property, plant and equipment, depreciable life	40 years
Pipeline and Equipment | Minimum
Property Plant And Equipment [Line Items]
Property, plant and equipment, depreciable life	10 years
Pipeline and Equipment | Maximum
Property Plant And Equipment [Line Items]
Property, plant and equipment, depreciable life	30 years
Other | Minimum
Property Plant And Equipment [Line Items]
Property, plant and equipment, depreciable life	5 years
Other | Maximum
Property Plant And Equipment [Line Items]
Property, plant and equipment, depreciable life	25 years

Property, Plant and Equipment37

Property, Plant and Equipment - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense	$ 6.2	$ 5.9

Accrued Liabilities - Third P38

Accrued Liabilities - Third Parties - Schedule of Accrued Liabilities (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Transportation, project engineering	$ 9.5	$ 3.5
Property taxes	2.1	0.6
Professional fees	0.4	0.3
Other accrued liabilities	0.7	1.2
Accrued liabilities - third parties	$ 12.7	$ 5.6

Related Party Debt - Schedule o

Related Party Debt - Schedule of Consolidated Related Party Debt Obligations (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016	Nov. 11, 2015	Nov. 03, 2014
Line Of Credit Facility [Line Items]
Outstanding borrowing	$ 685,300,000	$ 686,000,000
Unamortized debt issuance costs	$ (1,600,000)	$ (900,000)
Five Year Fixed Facility, fixed rate, due March 1, 2022 | Shell Treasury Center West Inc
Line Of Credit Facility [Line Items]
Debt instrument term	5 years
Five Year Revolver, variable rate, due October 31, 2019 | Shell Treasury Center West Inc
Line Of Credit Facility [Line Items]
Line of credit facility maximum borrowing capacity				$ 300,000,000
Debt instrument term	5 years
364-Day Revolver, variable rate, due March 1, 2017 | Shell Treasury Center West Inc
Line Of Credit Facility [Line Items]
Line of credit facility maximum borrowing capacity			$ 180,000,000
Debt instrument term	364 days	364 days
Fixed Facility | Five Year Fixed Facility, fixed rate, due March 1, 2022
Line Of Credit Facility [Line Items]
Outstanding borrowing	$ 0	$ 0
Fixed Facility | Five Year Fixed Facility, fixed rate, due March 1, 2022 | Shell Treasury Center West Inc
Line Of Credit Facility [Line Items]
Line of credit facility maximum borrowing capacity	$ 600,000,000
Debt instrument term	5 years
Revolving Credit Facility | Zydeco
Line Of Credit Facility [Line Items]
Outstanding borrowing	$ 0	0
Revolving Credit Facility | Zydeco | Shell Treasury Center West Inc
Line Of Credit Facility [Line Items]
Line of credit facility maximum borrowing capacity	30,000,000
Revolving Credit Facility | Five Year Revolver, variable rate, due October 31, 2019
Line Of Credit Facility [Line Items]
Outstanding borrowing	686,900,000	686,900,000
Revolving Credit Facility | Five Year Revolver, variable rate, due October 31, 2019 | Shell Treasury Center West Inc
Line Of Credit Facility [Line Items]
Line of credit facility maximum borrowing capacity	$ 760,000,000
Debt instrument term	5 years
Remaining borrowing capacity	$ 73,100,000
Revolving Credit Facility | 364-Day Revolver, variable rate, due March 1, 2017
Line Of Credit Facility [Line Items]
Outstanding borrowing	$ 0	$ 0
Revolving Credit Facility | 364-Day Revolver, variable rate, due March 1, 2017 | Shell Treasury Center West Inc
Line Of Credit Facility [Line Items]
Debt instrument term	364 days

Related Party Debt - Additional

Related Party Debt - Additional Information (Details) - USD ($)	Mar. 01, 2017	Sep. 27, 2016	Mar. 29, 2016	Aug. 06, 2014	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Nov. 11, 2015	Jun. 29, 2015	May 12, 2015	Nov. 03, 2014
Line Of Credit Facility [Line Items]
Interest and fee expenses					$ 4,000,000	$ 2,100,000
Repayments of debt					$ 0	$ 410,000,000
Revolving Credit Facility | Zydeco
Line Of Credit Facility [Line Items]
Limit on indebtedness				$ 100,000,000
Weighted average interest rate					2.60%
Revolving Credit Facility | Zydeco | STCW
Line Of Credit Facility [Line Items]
Line of credit facility maximum borrowing capacity				$ 30,000,000
Line of credit facility, expiration period				6 months
Shell Treasury Center West Inc | Five Year Fixed Facility, fixed rate, due March 1, 2022
Line Of Credit Facility [Line Items]
Debt instrument term					5 years
Shell Treasury Center West Inc | Five Year Revolver, variable rate, due October 31, 2019
Line Of Credit Facility [Line Items]
Repayments of debt			$ 272,600,000
Debt instrument term					5 years
Line of credit facility maximum borrowing capacity											$ 300,000,000
Shell Treasury Center West Inc | Amended And Restated Revolver
Line Of Credit Facility [Line Items]
Line of credit facility maximum borrowing capacity		$ 760,000,000
Issuance fee		600,000
Line of credit facility, increase in maximum borrowing capacity										$ 400,000,000
Weighted average interest rate					2.30%
Shell Treasury Center West Inc | Amended And Restated Revolver | Minimum
Line Of Credit Facility [Line Items]
Limit on indebtedness		$ 100,000,000
Shell Treasury Center West Inc | 364-Day Revolver, variable rate, due March 1, 2017
Line Of Credit Facility [Line Items]
Repayments of debt			$ 137,400,000
Debt instrument term					364 days		364 days
Line of credit facility maximum borrowing capacity								$ 180,000,000
Shell Treasury Center West Inc | 364-Day Revolver, variable rate, due March 1, 2017 | STCW
Line Of Credit Facility [Line Items]
Line of credit facility maximum borrowing capacity									$ 100,000,000
Shell Treasury Center West Inc | Fixed Facility | Five Year Fixed Facility, fixed rate, due March 1, 2022
Line Of Credit Facility [Line Items]
Debt instrument term					5 years
Line of credit facility maximum borrowing capacity					$ 600,000,000
Limit on indebtedness	$ 100,000,000
Issuance fee	$ 700,000
Fixed interest rate	3.23%
Shell Treasury Center West Inc | Fixed Facility | Five Year Fixed Facility, fixed rate, due March 1, 2022 | STCW
Line Of Credit Facility [Line Items]
Line of credit facility maximum borrowing capacity	$ 600,000,000
Shell Treasury Center West Inc | Revolving Credit Facility | Zydeco
Line Of Credit Facility [Line Items]
Line of credit facility maximum borrowing capacity					$ 30,000,000
Shell Treasury Center West Inc | Revolving Credit Facility | Five Year Revolver, variable rate, due October 31, 2019
Line Of Credit Facility [Line Items]
Debt instrument term					5 years
Line of credit facility maximum borrowing capacity					$ 760,000,000
Shell Treasury Center West Inc | Revolving Credit Facility | 364-Day Revolver, variable rate, due March 1, 2017
Line Of Credit Facility [Line Items]
Debt instrument term					364 days

Equity - At-the-Market Program

Equity - At-the-Market Program (Details) - USD ($)	Mar. 29, 2016	Mar. 02, 2016	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Class of Stock [Line Items]
Issuance of common units, maximum (in units)		$ 300,000,000
Consideration for units issued in connection with private placement			$ 0	$ 8,700,000
Aggregate percentage of general partner interest			2.00%
Shell Treasury Center West Inc | Five Year Revolver
Class of Stock [Line Items]
Debt instrument term			5 years
Shell Treasury Center West Inc | 364 Day Revolver
Class of Stock [Line Items]
Debt instrument term			364 days		364 days
General Partner
Class of Stock [Line Items]
Units issued in connection with private placement (in units)				15,307
Consideration for units issued in connection with private placement	$ 8,200,000			$ 500,000
Aggregate percentage of general partner interest	2.00%		2.00%	2.00%
General Public | Common Units
Class of Stock [Line Items]
Units issued in connection with private placement (in units)				750,000
Net proceeds from public offerings				$ 25,400,000
Gross proceed issuance of private placement offering				$ 25,500,000
Common units per share (in units per share)	$ 31.75			$ 34
Placement fees	$ 200,000			$ 100,000

Equity - Public Offering (Detai

Equity - Public Offering (Details) - USD ($) $ / shares in Units, $ in Millions	Mar. 29, 2016	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Class of Stock [Line Items]
Consideration for units issued in connection with private placement		$ 0	$ 8.7
Aggregate percentage of general partner interest		2.00%
Shell Treasury Center West Inc | Five Year Revolver
Class of Stock [Line Items]
Debt instrument term		5 years
Shell Treasury Center West Inc | 364 Day Revolver
Class of Stock [Line Items]
Debt instrument term		364 days		364 days
General Partner
Class of Stock [Line Items]
Units issued in connection with public offering (in units)	258,163
Consideration for units issued in connection with private placement	$ 8.2		$ 0.5
Aggregate percentage of general partner interest	2.00%	2.00%	2.00%
General Public | Common Units
Class of Stock [Line Items]
Units issued in connection with public offering (in units)	12,650,000
Net proceeds from public offering	$ 395.1
Gross proceeds from public offering	$ 401.6
Common units per share (in units per share)	$ 31.75		$ 34
Underwriter fees	$ 6.3
Placement fees	$ 0.2		$ 0.1

Equity - Units Outstanding (Det

Equity - Units Outstanding (Details) - shares	Mar. 29, 2016	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Class of Stock [Line Items]
Limited partners' capital account, units outstanding (in units)		177,317,444
Capital units, publicly owned (in units)		180,936,167		180,936,167
Ownership interest (in percentage)		49.20%
Aggregate percentage of general partner interest		2.00%
Common Units | General Public
Class of Stock [Line Items]
Limited partners' capital account, units outstanding (in units)		88,367,308		88,367,308
Capital units, publicly owned (in units)		88,367,308		88,367,308
Common Units | Shell Pipeline Company L P
Class of Stock [Line Items]
Limited partners' capital account, units outstanding (in units)		88,950,136		21,475,068
Capital units, publicly owned (in units)		88,950,136		21,475,068
General Partner
Class of Stock [Line Items]
Capital units, publicly owned (in units)		3,618,723		3,618,723
Aggregate percentage of general partner interest	2.00%	2.00%	2.00%

Equity - Schedule of Number of

Equity - Schedule of Number of Units Outstanding (Details)	3 Months Ended
	Mar. 31, 2017shares
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in units)	180,936,167
Expiration of subordination period (in units)	0
Ending balance (in units)	180,936,167
General Partner
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in units)	3,618,723
Expiration of subordination period (in units)	0
Ending balance (in units)	3,618,723
General Public | Common Units
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in units)	88,367,308
Expiration of subordination period (in units)	0
Ending balance (in units)	88,367,308
Shell Pipeline Company L P | Common Units
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in units)	21,475,068
Expiration of subordination period (in units)	67,475,068
Ending balance (in units)	88,950,136
Shell Pipeline Company L P | Subordinate Units
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in units)	67,475,068
Expiration of subordination period (in units)	(67,475,068)
Ending balance (in units)	0

Equity - Expiration of Subordin

Equity - Expiration of Subordination Period (Details) - Common units – public	Feb. 15, 2017shares
Class of Stock [Line Items]
Shares converted (in shares)	67,475,068
Conversion ratio (in common units per subordinated units)	1

Equity - Schedule of Distributi

Equity - Schedule of Distributions Declared and/or Paid (Details) - USD ($) $ / shares in Units, $ in Millions	Mar. 29, 2016	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015
Distribution Made To Limited Partner [Line Items]
Distributions declared and/or paid		$ 63.6	$ 58.6	$ 53.9	$ 49	$ 41.7	$ 35.3
Distributions paid per limited partner unit (in dollars per unit)		$ 0.291	$ 0.27700	$ 0.26375	$ 0.2500	$ 0.2350	$ 0.2200
Aggregate percentage of general partner interest		2.00%
Shell Pipeline Company L P
Distribution Made To Limited Partner [Line Items]
Distributions declared and/or paid		$ 0	$ 18.7	$ 17.8	$ 16.9	$ 15.8	$ 14.9
Common Units | General Public
Distribution Made To Limited Partner [Line Items]
Distributions declared and/or paid		25.7	24.5	23.3	22	17.9	13.8
Common Units | Shell Pipeline Company L P
Distribution Made To Limited Partner [Line Items]
Distributions declared and/or paid		25.9	5.9	5.7	5.4	5.1	4.7
General Partner
Distribution Made To Limited Partner [Line Items]
Distributions declared and/or paid		$ 1.3	1.2	1.1	1	$ 0.9	0.7
Aggregate percentage of general partner interest	2.00%	2.00%				2.00%
General Partner | IDR's
Distribution Made To Limited Partner [Line Items]
Distributions declared and/or paid		$ 10.7	$ 8.3	$ 6	$ 3.7	$ 2	$ 1.2

Equity - Distributions to Nonco

Equity - Distributions to Noncontrolling Interest (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Zydeco
Class of Stock [Line Items]
Distributions to noncontrolling interest	$ 3.2	$ 12.4

Net Income Per Limited Partne48

Net Income Per Limited Partner Unit - Schedule of Allocation of Net Income to Arrive at Net Income Per Limited Partner Unit (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Limited Partners Capital Account [Line Items]
Net income	$ 73	$ 68
Less: Net income attributable to noncontrolling interests	2.2	12.7
Net income attributable to the Partnership	70.8	55.3
Distribution declared	63.6	41.7
Income in excess of distributions	7.2	13.6
General Partner
Limited Partners Capital Account [Line Items]
Net income attributable to the Partnership	12.1	3.1
Distribution declared	12	2.9
Income in excess of distributions	0.1	0.2
Limited Partners' Common Units
Limited Partners Capital Account [Line Items]
Net income attributable to the Partnership	58.7	30.5
Distribution declared	51.6	23
Income in excess of distributions	7.1	7.5
Limited Partner's Subordinated Units
Limited Partners Capital Account [Line Items]
Net income attributable to the Partnership		21.7
Distribution declared	$ 0	15.8
Income in excess of distributions		$ 5.9

Net Income Per Limited Partne49

Net Income Per Limited Partner Unit - Schedule of Basic and Diluted Net Income Per Unit (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Distribution Made To Limited Partner [Line Items]
Distribution declared	$ 63.6	$ 41.7
Income in excess of distributions	7.2	13.6
Net income attributable to the Partnership	70.8	55.3
General Partner
Distribution Made To Limited Partner [Line Items]
Distribution declared	12	2.9
Income in excess of distributions	0.1	0.2
Net income attributable to the Partnership	12.1	3.1
Limited Partners' Common Units
Distribution Made To Limited Partner [Line Items]
Distribution declared	51.6	23
Income in excess of distributions	7.1	7.5
Net income attributable to the Partnership	$ 58.7	$ 30.5
Weighted average units outstanding (in millions):
Weighted average units outstanding, basic and diluted (in shares)	177.3	84.9
Net income per Limited Partner Unit (in dollars):
Net income per Limited Partner Unit, basic and diluted (in dollars per share)	$ 0.33	$ 0.36
Limited Partner's Subordinated Units
Distribution Made To Limited Partner [Line Items]
Distribution declared	$ 0	$ 15.8
Income in excess of distributions		5.9
Net income attributable to the Partnership		$ 21.7
Weighted average units outstanding (in millions):
Weighted average units outstanding, basic and diluted (in shares)		67.5
Net income per Limited Partner Unit (in dollars):
Net income per Limited Partner Unit, basic and diluted (in dollars per share)	$ 0	$ 0.32

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Tax Disclosure [Abstract]
Income tax expense	$ 0	$ 0

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Millions	Sep. 01, 2016USD ($)
Commitments and Contingencies Disclosure [Abstract]
Tariff monthly payment	$ 0.4
Initial term	10 years
Renewal term	1 year

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Millions	Apr. 28, 2017	Apr. 19, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	May 04, 2017
Subsequent Event [Line Items]
Distributions paid per limited partner unit (in dollars per unit)			$ 0.291	$ 0.27700	$ 0.26375	$ 0.2500	$ 0.2350	$ 0.2200
Subsequent Event
Subsequent Event [Line Items]
Distributions paid per limited partner unit (in dollars per unit)		$ 0.291
Subsequent Event | Shell Chemical LP, Shell GOM Pipeline Company LP, And SPLC
Subsequent Event [Line Items]
Acquired ownership interest									100.00%
Purchase price									$ 630
Subsequent Event | Zydeco
Subsequent Event [Line Items]
Transaction price	$ 21