Shell Midstream Partners (SHLX) 10-Q 3 Nov 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Nov. 03, 2017
Document Information [Line Items]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
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)		187,782,369

UNAUDITED CONDENSED CONSOLIDATE

UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions		Sep. 30, 2017		Dec. 31, 2016		Sep. 30, 2016	[3]	Dec. 31, 2015	[3]
Current assets
Cash and cash equivalents		$ 171.9	[1]	$ 121.9	[1],[2]	$ 160.8		$ 93
Accounts receivable – third parties, net		12.9		20.8	[2]
Accounts receivable – related parties		16.2		12.1	[2]
Allowance oil		10.7		11.7	[2]
Prepaid expenses		1.2		6.5	[2]
Total current assets		212.9		173	[2]
Equity method investments		253.8		262.4	[2]
Property, plant and equipment, net		608.9		610.6	[2]
Cost investments		39.8		39.8	[2]
Other assets		1.3		0.6	[2]
Total assets		1,116.7		1,086.4	[2]
Current liabilities
Accounts payable – third parties		2.5		4.1	[2]
Accounts payable – related parties		10.5		5.4	[2]
Deferred revenue – third parties		6.5		6	[2]
Deferred revenue – related parties		20.8		7.9	[2]
Accrued liabilities – third parties		17.2		6.9	[2]
Accrued liabilities – related parties		5.9		5.1	[2]
Total current liabilities		63.4		35.4	[2]
Noncurrent liabilities
Debt payable – related party		1,000.6		686	[2]
Lease liability		24.4		24.9	[2]
Asset retirement obligations		1.4		1.4	[2]
Other unearned income		2.7		2.1	[2]
Total noncurrent liabilities		1,029.1		714.4	[2]
Total liabilities		1,092.5		749.8	[2]
Commitments and Contingencies (Note 11)					[2]
EQUITY
Total partners' capital		3.4		98.3	[2]
Noncontrolling interest		20.8		21.6	[2]
Net parent investment		0		216.7	[2]
Total equity	[4]	24.2		336.6	[2]
Total liabilities and equity		1,116.7		1,086.4	[2]
Shell Pipeline Company L P
EQUITY
General partner unitholders		(2,256.8)		(1,873.7)	[2]
Common Units | General Public
EQUITY
Limited partner unitholders		2,770.4		2,485.7	[2]
Common Units | Shell Pipeline Company L P
EQUITY
Limited partner unitholders		(510.2)		(124.1)	[2]
Subordinated Units | Shell Pipeline Company L P
EQUITY
Limited partner unitholders		0		(389.6)	[2]
Total equity		$ 0		$ (389.6)
[1]	The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta,Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.
[2]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.
[3]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.
[4]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.

UNAUDITED CONDENSED CONSOLIDAT3

UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - shares	Sep. 30, 2017	Dec. 31, 2016
Limited partners' capital account, units outstanding (in shares)	187,782,369
Shell Pipeline Company L P
General partners' capital account, units issued (in shares)	3,832,293	3,618,723
General partners' capital account, units outstanding (in shares)	3,832,293	3,618,723
Common Units | General Public
Limited partners' capital account, units issued (in shares)	98,832,233	88,367,308
Limited partners' capital account, units outstanding (in shares)	98,832,233	88,367,308
Common Units | Shell Pipeline Company L P
Limited partners' capital account, units issued (in shares)	88,950,136	21,475,068
Limited partners' capital account, units outstanding (in shares)	88,950,136	21,475,068
Subordinated Units | Shell Pipeline Company L P
Limited partners' capital account, units issued (in shares)	0	67,475,068
Limited partners' capital account, units outstanding (in shares)	0	67,475,068

UNAUDITED CONDENSED CONSOLIDAT4

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016		Sep. 30, 2017		Sep. 30, 2016
Revenue
Transportation services and storage - third parties	$ 52.9	$ 53.8	[1]	$ 163.7	[2]	$ 174.9	[1]
Transportation services and storage - related parties	29.8	28.1	[1]	82.5	[2]	86	[1]
Lease revenue - related parties	11.7	0	[1]	19.4	[2]	0	[1]
Total revenue	94.4	81.9	[1]	265.6	[2]	260.9	[1]
Costs and expenses
Operations and maintenance – third parties	25.8	14.1	[1]	64.3	[2]	41.7	[1]
Operations and maintenance – related parties	8.4	7.5	[1]	26.6	[2]	22.6	[1]
General and administrative – third parties	1	2.2	[1]	5.6	[2]	6.4	[1]
General and administrative – related parties	8.6	7.4	[1]	25.2	[2]	22.3	[1]
Depreciation, amortization and accretion	8.9	9.1	[1]	28	[2],[3]	27.1	[1],[4]
Property and other taxes	3.6	2.6	[1]	11.2	[2]	10.3	[1]
Total costs and expenses	56.3	42.9	[1]	160.9	[2]	130.4	[1]
Operating income	38.1	39	[1]	104.7	[2]	130.5	[1]
Income from equity investments	41.2	21.4	[1]	117.1	[2]	70.2	[1]
Dividend income from cost investments	4.8	4.2	[1]	18.3	[2]	11.6	[1]
Other income	0.1	0	[1]	0.1	[2]	0	[1]
Investment, dividend and other income	46.1	25.6	[1]	135.5	[2]	81.8	[1]
Interest expense, net	9.7	2.8	[1]	22	[2]	7.8	[1]
Income before income taxes	74.5	61.8	[1]	218.2	[2]	204.5	[1]
Income tax expense	0	0	[1]	0	[2]	0	[1]
Net income	74.5	61.8	[1]	218.2	[2],[3],[5]	204.5	[1],[4]
Less: Net income attributable to Parent	0	3	[1]	3	[2]	11.4	[1]
Less: Net income attributable to noncontrolling interests	1.9	2.5	[1]	6.3	[2]	17.7	[1]
Net income attributable to the Partnership	72.6	56.3	[1]	208.9	[2]	175.4	[1]
Limited Partners' interest in net income attributable to the Partnership	$ 55	$ 49.1	[1]	$ 164.9	[2]	$ 160.1	[1]
Net income per Limited Partner Unit - Basic and Diluted
Distributions per Limited Partner unit (in dollars per share)	$ 0.3180	$ 0.26375	[1]	$ 0.9131	[2]	$ 0.74880	[1]
Shell Pipeline Company L P
Costs and expenses
General partner's interest in net income attributable to the Partnership	$ 17.6	$ 7.2	[1]	$ 44	[2]	$ 15.3	[1]
Common
Costs and expenses
Net income attributable to the Partnership	$ 55	$ 30.4		$ 164.9		$ 97.4
Net income per Limited Partner Unit - Basic and Diluted
Net income per Limited Partner unit (in dollars per share)	$ 0.31	$ 0.28	[1]	$ 0.93	[2]	$ 0.98	[1]
Subordinated
Costs and expenses
Net income attributable to the Partnership		$ 18.7				$ 62.7
Net income per Limited Partner Unit - Basic and Diluted
Net income per Limited Partner unit (in dollars per share)	$ 0	$ 0.28	[1]	$ 0	[2]	$ 0.93	[1]
Common units – public
Costs and expenses
Net income				$ 83.9
Weighted average Limited Partner Units outstanding - Basic and Diluted (in millions)
Weighted average Limited Partner units outstanding - Common (in shares)	90.2	88.3	[1]	89	[2]	77.7	[1]
Common units – public | Shell Pipeline Company L P
Costs and expenses
Net income				$ 81
Common units – SPLC | Shell Pipeline Company L P
Weighted average Limited Partner Units outstanding - Basic and Diluted (in millions)
Weighted average Limited Partner units outstanding - Common (in shares)	89	21.5	[1]	89	[2]	21.5	[1]
Subordinated units – SPLC | Shell Pipeline Company L P
Weighted average Limited Partner Units outstanding - Basic and Diluted (in millions)
Weighted average Limited Partner Units outstanding - Subordinated (in shares)	0	67.5	[1]	0	[2]	67.5	[1]
[1]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.
[2]	The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.
[3]	The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta,Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.
[4]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.
[5]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.

UNAUDITED CONDENSED CONSOLIDAT5

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	[3]	Sep. 30, 2016	[5]
Cash flows from operating activities
Net income	$ 218.2	[1],[2]	$ 204.5	[4]
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation, amortization and accretion	28	[2]	27.1	[4]
Non-cash interest expense	0.3		0.2
Allowance oil reduction to net realizable value	0.3		0
Undistributed equity earnings	(4.1)		2.7
Changes in operating assets and liabilities
Accounts receivable	(0.9)		7.3
Allowance oil	(1.7)		(3.8)
Prepaid expenses and other assets	4.4		5
Accounts payable	3.6		(2.3)
Deferred revenue	14		(0.4)
Accrued liabilities	13.9		8.2
Net cash provided by operating activities	276		248.5
Cash flows from investing activities
Capital expenditures	(35.5)		(28.8)
Acquisitions	(200.7)		(120)
Purchase price adjustment	0.4		0
Return of investment	12.3		9.6
April 2017 Divestiture	0.8		0
Net cash used in investing activities	(222.7)		(139.2)
Cash flows from financing activities
Net proceeds from public offerings	277.9		818.1
Borrowing under credit facility	580		296.7
Contributions from general partner	5.8		9.8
Repayment of credit facilities	(265)		(410)
Capital distributions to general partner	(429.3)		(599.2)
Distributions to noncontrolling interest	(8.6)		(17.1)
Distributions to unitholders and general partner	(190.4)		(126)
Net distributions to Parent	(6.3)		(16.9)
Other contributions from Parent	13.6		3.1
Proceeds from April 2017 Divestiture	20.2		0
Capital lease payments	(0.5)		0
Credit facility issuance costs	(0.7)		0
Net cash used in financing activities	(3.3)		(41.5)
Net increase in cash and cash equivalents	50		67.8
Cash and cash equivalents at beginning of the period	121.9	[6]	93
Cash and cash equivalents at end of the period	171.9		160.8
Non-cash investing and financing transactions
Net assets not contributed to the Partnership	(12.7)		0
Change in accrued capital expenditures	1.5		(5.3)
Other non-cash contributions from Parent	1.5		0.3
Other non-cash capital distributions to general partner	0		(7.1)
Other non-cash contribution from general partner	0		7.1
Other non-cash credit facilities issuance costs	$ 0		$ (0.6)
[1]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.
[2]	The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.
[3]	The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta,Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.
[4]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.
[5]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.
[6]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.

UNAUDITED CONDENSED CONSOLIDAT6

UNAUDITED CONDENSED CONSOLIDATED STATEMENT OF CHANGES IN EQUITY - 9 months ended Sep. 30, 2017 - USD ($) $ in Millions	Total		Non-controlling Interest	Net Parent Investment	[2]	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	$ 336.6	[1],[2]	$ 21.6	$ 216.7		$ 2,485.7	$ (124.1)	$ (389.6)	$ (1,873.7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	218.2	[2],[3],[4]	6.3	3		83.9	81		44
Other contributions from Parent	13.5	[2]							13.5
Net proceeds from public offering	283.7	[2]				277.9			5.8
Distributions to unitholders and general partner	(190.4)	[2]				(77.1)	(58.8)	(18.7)	(35.8)
Distribution to noncontrolling interest	(8.6)	[2]	(8.6)
Proceeds from April 2017 divestiture	20.2	[2]	1.5						18.7
Expiration of subordinated period							(408.3)	408.3
May 2017 Acquisition	(630)	[2]		(200.7)					(429.3)
Net assets not contributed to the Partnership	(19)			(19)
Ending Balance at Sep. 30, 2017	$ 24.2	[2]	$ 20.8	$ 0		$ 2,770.4	$ (510.2)	$ 0	$ (2,256.8)
[1]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.
[2]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.
[3]	The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.
[4]	The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta,Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.

Description of Business and Bas

Description of Business and Basis of Presentation	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Basis of Presentation	Except as noted within the context of each note disclosure, the dollar amounts presented in the tabular data within these note disclosures are stated in millions of dollars. The financial information for the nine months ended September 30, 2017, the three and nine months ended September 30, 2016, and at December 31, 2016, has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations (see Note 2 - Acquisitions and Divestitures). 1. 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 acquired 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. 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 well as interests in entities that own natural gas and refinery gas pipelines which transport offshore natural gas to market hubs and deliver refinery gas from refineries and plants to chemical sites along the Gulf Coast. As of September 30, 2017 , we own interests in nine crude oil pipeline systems, three refined products systems, one natural gas gathering pipeline system, one gas pipeline system, and a crude tank storage and terminal system. The following table reflects our ownership, and Shell's retained ownership as of September 30, 2017 . SHLX Ownership Shell's Retained Ownership Pecten Midstream LLC (“Pecten”) 100.0 % — Sand Dollar Pipeline LLC (“Sand Dollar”) 100.0 % — Zydeco Pipeline Company LLC (“Zydeco”) 92.5 % 7.5 % Bengal Pipeline Company LLC (“Bengal”) 50.0 % — Odyssey Pipeline LLC (“Odyssey”) 49.0 % 22.0 % Mars Oil Pipeline Company LLC (“Mars”) 48.6 % 22.9 % Poseidon Oil Pipeline Company LLC (“Poseidon”) 36.0 % — Proteus Oil Pipeline Company, LLC (“Proteus”) 10.0 % — Endymion Oil Pipeline Company, LLC (“Endymion”) 10.0 % — Colonial Pipeline Company (“Colonial”) 6.0 % 10.12 % Explorer Pipeline Company (“Explorer”) 2.62 % 35.97 % Cleopatra Gas Gathering Company, LLC (“Cleopatra”) 1.0 % — 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 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. 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 and nine months ended September 30, 2017 and 2016 include all adjustments we believe are necessary for a fair statement of the results for the interim periods presented. These adjustments are of a normal recurring nature unless otherwise disclosed. Operating results for the interim periods 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. The acquisition of Delta, Na Kika and Refinery Gas Pipeline (the “Shell Delta, Na Kika and Refinery Gas Pipeline Operations” or “Delta, Na Kika and Refinery Gas Pipeline”) was a transfer of businesses between entities under common control, which requires it to be accounted for as if the transfer had occurred at the beginning of the period of transfer, with prior periods retrospectively adjusted to furnish comparative financial information. Accordingly, the accompanying financial statements and notes have been retrospectively adjusted to include the historical results and financial position of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations prior to the effective date of the acquisition. See Note 2 - Acquisitions and Divestitures for additional information. 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 nine months ended September 30, 2017 , other than those noted below. Revenue Recognition Certain transportation services agreements with a related party are considered operating leases under GAAP. Revenues from these agreements are recorded within Lease revenue - related parties in the condensed consolidated statements of income. See Note 3-Related Party Transactions for additional information. 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 ASU'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 will adopt the requirements of the new standard in the first quarter of 2018 under the modified retrospective transition method. As part of our implementation efforts to date, all of our revenue contracts have been subject to review to evaluate the effect of the new standard on our revenue recognition practices. We have also made progress in evaluating new disclosure requirements and identifying impacts to our business processes, systems and controls to support recognition and disclosure under the new guidance. We expect the adoption of the new standard will change the way we recognize revenue from our committed shippers under transportation services agreements. We anticipate the new standard will result in earlier recognition of revenue related to cash collected from customers for shortfalls under these agreements, which is recorded as deferred revenue. We currently recognize deferred revenue under these arrangements into revenue once all contingencies or potential performance obligations associated with the related volumes have been satisfied or expired. Upon adoption of the new standard and application of the breakage model to our deferred revenue, we anticipate a cumulative transition adjustment resulting from the earlier recognition of revenue with a corresponding adjustment to beginning retained earnings and are in the process of quantifying the impact. We have also identified potential contracts or elements of contracts that may require a change in presentation on our income statement, specifically related to the service component of leases, product loss allowance, gross versus net presentation and reimbursements of capital expenditures. Currently, we do not anticipate these to materially impact our financial statements as there will be no net impact to income before taxes. However, this is still under review and subject to our ongoing assessment of the guidance. For additional information on accounting pronouncements issued prior to September 2017, refer to Note 2—Summary of Significant Accounting Policies in the Notes to Consolidated Financial Statements of our 2016 Annual Report.

Acquisitions and Divestitures

Acquisitions and Divestitures	9 Months Ended
	Sep. 30, 2017
Business Combinations [Abstract]
Acquisitions and Divestitures	Acquisitions and Divestitures On May 10, 2017, we acquired a 100% interest in Delta, Na Kika and Refinery Gas Pipeline for $630.0 million in consideration (the “May 2017 Acquisition”). As part of the May 2017 Acquisition, SPLC and Shell GOM Pipeline Company LP (“Shell GOM”) contributed all but the working capital of Delta and Na Kika to Pecten, and Shell Chemical LP (“Shell Chemical”) contributed all but the working capital of Refinery Gas Pipeline to Sand Dollar. The May 2017 Acquisition closed pursuant to a Purchase and Sale Agreement dated May 4, 2017 (the “May 2017 Purchase and Sale Agreement”), among the Operating Company, us, Shell Chemical, Shell GOM and SPLC. Shell Chemical, Shell GOM and SPLC are each wholly owned subsidiaries of Shell. We funded the May 2017 Acquisition with $50.0 million of cash on hand, $73.1 million in borrowings under our Five Year Revolver (as defined in Note 7—Related Party Debt ), and $506.9 million in borrowings under our Five Year Fixed Facility (as defined in Note 7—Related Party Debt ) with Shell Treasury Center (West) Inc. (“STCW”), an affiliate of Shell. Total transaction costs of $0.8 million were expensed as incurred. The terms of the May 2017 Acquisition were approved by the Board of Directors of our general partner (the “Board”) and by the conflicts committee of the Board, which consists entirely of independent directors. The conflicts committee engaged an independent financial advisor and legal counsel. In accordance with the May 2017 Purchase and Sale Agreement, Shell Chemical has agreed to reimburse us for costs and expenses incurred in connection with the conversion of a section of pipe from the Convent refinery to Sorrento from refinery gas service to butane service. The May 2017 Purchase and Sale Agreement contains other customary representations, warranties and covenants. In connection with the May 2017 Purchase and Sale Agreement, we granted Shell Chemical a purchase option and right of first refusal with respect to Refinery Gas Pipeline and certain other related assets and the ownership interests in Sand Dollar. The purchase option may be triggered by, among other things, (i) a third party obtaining the right to use any or all of a Refinery Gas Pipeline; (ii) the loss of all volume on a Refinery Gas Pipeline that would result in it being permanently shutdown for two years or more; (iii) the termination of a transportation services agreement between Shell Chemical and Sand Dollar (“Refinery Gas Pipeline Agreement”); (iv) the expiration of the term of a Refinery Gas Pipeline Agreement; or (v) a change of control of our general partner; provided, however, that in the case of (i) through (iv), the purchase option would only be applicable to the Refinery Gas Pipeline impacted by such event. In addition, in the event that Sand Dollar receives an offer to sell all or a portion of the Refinery Gas Pipelines or the ownership interests in Sand Dollar from a third party, Shell Chemical has a right of first refusal with respect to such Refinery Gas Pipelines or ownership interests, as applicable, for so long as any Refinery Gas Pipeline Agreement between Shell Chemical and Sand Dollar is in effect. In connection with the May 2017 Acquisition we acquired historical carrying value of property, plant and equipment, net and other assets under common control as follows: Delta $ 40.1 Na Kika 26.0 Refinery Gas Pipeline 134.6 May 2017 Acquisition $ 200.7 We recognized $429.3 million of consideration in excess of the book value of net assets acquired as a capital distribution to our general partner in accordance with our policy for common control transactions. During the three months ended September 30, 2017, we adjusted the historical carrying value of property, plant and equipment acquired in connection with the May 2017 Acquisition. The adjustment resulted in a decrease to property, plant and equipment of $9.9 million with a corresponding increase to the capital distribution to our general partner. For the period from closing through September 30, 2017, we recognized $40.1 million in revenues and $18.9 million of net earnings related to the assets acquired. Retrospective adjusted information tables The following tables present our financial position and our results of operations and of cash flows giving effect to the May 2017 Acquisition of the Delta, Na Kika and Refinery Gas Pipeline Operations. The results of Delta, Na Kika and Refinery Gas Pipeline prior to the closing date of the acquisition are included in “Delta, Na Kika and Refinery Gas Pipeline Operations” and the consolidated results are included in “Consolidated Results” within the tables below: December 31, 2016 Shell Midstream Partners, L.P. (1) Delta, Na Kika and Refinery Gas Pipeline Operations (2) Consolidated Results ASSETS Current assets Cash and cash equivalents $ 121.9 $ — $ 121.9 Accounts receivable – third parties, net 18.4 2.4 20.8 Accounts receivable – related parties 10.1 2.0 12.1 Allowance oil 9.0 2.7 11.7 Prepaid expenses 6.0 0.5 6.5 Total current assets 165.4 7.6 173.0 Equity method investments 262.4 — 262.4 Property, plant and equipment, net 398.0 212.6 610.6 Cost investments 39.8 — 39.8 Other assets — 0.6 0.6 Total assets $ 865.6 $ 220.8 $ 1,086.4 LIABILITIES Current liabilities Accounts payable – third parties $ 1.5 $ 2.6 $ 4.1 Accounts payable – related parties 5.2 0.2 5.4 Deferred revenue – third parties 6.0 — 6.0 Deferred revenue – related parties 7.9 — 7.9 Accrued liabilities – third parties 5.6 1.3 6.9 Accrued liabilities – related parties 5.1 — 5.1 Total current liabilities 31.3 4.1 35.4 Noncurrent liabilities Debt payable – related party 686.0 — 686.0 Lease liability – related party 24.9 — 24.9 Asset retirement obligations 1.4 — 1.4 Other unearned income 2.1 — 2.1 Total noncurrent liabilities 714.4 — 714.4 Total liabilities 745.7 4.1 749.8 Commitments and Contingencies (Note 11) EQUITY Common unitholders – public 2,485.7 — 2,485.7 Common unitholder – SPLC (124.1 ) — (124.1 ) Subordinated unitholder (389.6 ) — (389.6 ) General partner – SPLC (1,873.7 ) — (1,873.7 ) Total partners' capital 98.3 — 98.3 Noncontrolling interest 21.6 — 21.6 Net parent investment — 216.7 216.7 Total equity 119.9 216.7 336.6 Total liabilities and equity $ 865.6 $ 220.8 $ 1,086.4 (1) As previously reported in our Annual Report on Form 10-K for 2016. (2) The financial position of the Delta, Na Kika and Refinery Gas Pipeline Operations as of December 31, 2016. Three Months Ended September 30, 2016 Shell Midstream Partners, L.P. (1) Delta, Na Kika and Refinery Gas Pipeline Operations (2) Consolidated Results Revenue Third parties $ 46.1 $ 7.7 $ 53.8 Related parties 21.8 6.3 28.1 Total revenue 67.9 14.0 81.9 Costs and expenses Operations and maintenance – third parties 11.4 2.7 14.1 Operations and maintenance – related parties 5.3 2.2 7.5 General and administrative – third parties 2.2 — 2.2 General and administrative – related parties 5.7 1.7 7.4 Depreciation, amortization and accretion 6.0 3.1 9.1 Property and other taxes 1.3 1.3 2.6 Total costs and expenses 31.9 11.0 42.9 Operating income 36.0 3.0 39.0 Income from equity investments 21.4 — 21.4 Dividend income from cost investments 4.2 — 4.2 Investment and dividend income 25.6 — 25.6 Interest expense, net 2.8 — 2.8 Income before income taxes 58.8 3.0 61.8 Income tax expense — — — Net income 58.8 3.0 61.8 Less: Net income attributable to Parent — 3.0 3.0 Less: Net income attributable to noncontrolling interests 2.5 — 2.5 Net income attributable to the Partnership $ 56.3 $ — $ 56.3 (1) As previously reported in our Quarterly Report on Form 10-Q for the quarterly period ended September 30, 2016. (2) Our Parents' results of the Delta, Na Kika and Refinery Gas Pipeline Operations from July 1, 2016 through September 30, 2016. Nine Months Ended September 30, 2016 Shell Midstream Partners, L.P. (1) Delta, Na Kika and Refinery Gas Pipeline Operations (2) Consolidated Results Revenue Third parties $ 149.8 $ 25.1 $ 174.9 Related parties 65.9 20.1 86.0 Total revenue 215.7 45.2 260.9 Costs and expenses Operations and maintenance – third parties 33.1 8.6 41.7 Operations and maintenance – related parties 15.9 6.7 22.6 General and administrative – third parties 6.2 0.2 6.4 General and administrative – related parties 17.3 5.0 22.3 Depreciation, amortization and accretion 17.7 9.4 27.1 Property and other taxes 6.4 3.9 10.3 Total costs and expenses 96.6 33.8 130.4 Operating income 119.1 11.4 130.5 Income from equity investments 70.2 — 70.2 Dividend income from cost investments 11.6 — 11.6 Investment and dividend income 81.8 — 81.8 Interest expense, net 7.8 — 7.8 Income before income taxes 193.1 11.4 204.5 Income tax expense — — — Net income 193.1 11.4 204.5 Less: Net income attributable to Parent — 11.4 11.4 Less: Net income attributable to noncontrolling interests 17.7 — 17.7 Net income attributable to the Partnership $ 175.4 $ — $ 175.4 (1) As previously reported in our Quarterly Report on Form 10-Q for the nine month period ended September 30, 2016. (2) Our Parents' results of the Delta, Na Kika and Refinery Gas Pipeline Operations from January 1, 2016 through September 30, 2016. Nine Months Ended September 30, 2016 Shell Midstream Partners, L.P. (1) Delta, Na Kika and Refinery Gas Pipeline Operations (2) Consolidated Results Cash flows from operating activities Net income $ 193.1 $ 11.4 $ 204.5 Adjustments to reconcile net income to net cash provided by operating activities Depreciation, amortization and accretion 17.7 9.4 27.1 Non-cash interest expense 0.2 — 0.2 Undistributed equity earnings 2.7 — 2.7 Changes in operating assets and liabilities Accounts receivable 6.6 0.7 7.3 Allowance oil (3.6 ) (0.2 ) (3.8 ) Prepaid expenses 4.3 0.7 5.0 Accounts payable (1.6 ) (0.7 ) (2.3 ) Deferred revenue (0.4 ) — (0.4 ) Accrued liabilities 5.1 3.1 8.2 Net cash provided by operating activities 224.1 24.4 248.5 Cash flows from investing activities Capital expenditures (21.3 ) (7.5 ) (28.8 ) Acquisitions (120.0 ) — (120.0 ) Return of investment 9.6 — 9.6 Net cash used in investing activities (131.7 ) (7.5 ) (139.2 ) Cash flows from financing activities Net proceeds from public offerings 818.1 — 818.1 Borrowing under credit facility 296.7 — 296.7 Contributions from general partner 9.8 — 9.8 Repayment of credit facilities (410.0 ) — (410.0 ) Capital distributions to general partner (599.2 ) — (599.2 ) Distributions to noncontrolling interest (17.1 ) — (17.1 ) Distributions to unitholders and general partner (126.0 ) — (126.0 ) Net distributions to Parent — (16.9 ) (16.9 ) Other contribution from Parent 3.1 — 3.1 Net cash used in financing activities (24.6 ) (16.9 ) (41.5 ) Net increase in cash and cash equivalents 67.8 — 67.8 Cash and cash equivalents at beginning of the period 93.0 — 93.0 Cash and cash equivalents at end of the period $ 160.8 $ — $ 160.8 Supplemental Cash Flow Information Non-cash investing and financing transactions Change in accrued capital expenditures $ (1.1 ) $ (4.2 ) $ (5.3 ) Other non-cash contributions from Parent 0.3 — 0.3 Other non-cash capital distributions to general partner (7.1 ) — (7.1 ) Other non-cash contribution from general partner 7.1 — 7.1 Other non-cash credit facilities issuance costs (0.6 ) — (0.6 ) (1) As previously reported in our Quarterly Report on Form 10-Q for the nine month period ended September 30, 2016. (2) Our Parents' results of the Delta, Na Kika and Refinery Gas Pipeline Operations from January 1, 2016 through September 30, 2016. On April 28, 2017, Zydeco divested a small segment of its pipeline system (the “April 2017 Divestiture”) to Equilon Enterprises LLC d/b/a Shell Oil Products US (“SOPUS”) as part of the Motiva JV separation. The April 2017 Divestiture closed pursuant to a Pipeline Sale and Purchase Agreement (the “April 2017 Pipeline Sale and Purchase Agreement”) dated April 28, 2017 among Zydeco and SOPUS. We received $21.0 million in cash consideration for this sale, of which $19.4 million is attributable to the Partnership. The cash consideration represents $0.8 million for the book value of net assets divested, and $20.2 million in excess proceeds received from our Parent. The April 2017 Pipeline Sale and Purchase Agreement contained customary representations and warranties and indemnification by SOPUS. On August 9, 2016, we acquired a 2.62% equity interest in Explorer from SPLC (the “August 2016 Acquisition”) for $26.2 million . The August 2016 Acquisition was made in connection with SPLC’s right, as a current shareholder of Explorer, to acquire a portion of the equity interest being divested by another shareholder of Explorer. SPLC separately owns a 35.97% equity interest in Explorer. The August 2016 Acquisition closed on August 9, 2016 pursuant to a Share Purchase and Sale Agreement among us, the Operating Company and SPLC, and is accounted for as a transaction between entities under common control. We funded the August 2016 Acquisition with $26.3 million of cash on hand. Total transaction costs of $0.1 million were incurred. The terms of the August 2016 Acquisition were approved by the Board. On May 23, 2016, we acquired an additional 30.0% interest in Zydeco, an additional 1.0% interest in Bengal and an additional 3.0% interest in Colonial for $700.0 million in consideration (the “May 2016 Acquisition”). The May 2016 Acquisition closed pursuant to a Contribution Agreement (the “May 2016 Contribution Agreement”) dated May 17, 2016 among us, the Operating Company and SPLC and became effective on April 1, 2016, and is accounted for as a transaction between entities under common control. We funded the May 2016 Acquisition with $345.8 million from the net proceeds of a registered public offering of 10,500,000 common units representing limited partner interests in us (the “May 2016 Offering”), $50.4 million of cash on hand and $296.7 million in borrowings under the Five Year Revolver (as defined in Note 7—Related Party Debt ) with STCW, an affiliate of Shell. The remaining $7.1 million in consideration consisted of an issuance of 214,285 general partner units to our general partner in order to maintain its 2.0% general partner interest in us. Total transaction costs of $0.4 million were incurred in association with the May 2016 Acquisition. The terms of the May 2016 Acquisition were approved by the Board and by the conflicts committee of the Board, which consists entirely of independent directors. The conflicts committee engaged an independent financial advisor and legal counsel. In accordance with the May 2016 Contribution Agreement, SPLC has agreed to reimburse us for our proportionate share of certain costs and expenses incurred by Zydeco after April 1, 2016 with respect to a directional drill project to address soil erosion over a two-mile section of our 22-inch diameter pipeline under the Atchafalaya River and Bayou Shaffer in Louisiana. Such reimbursements will be treated as an additional capital contribution from the general partner at the time of payment. The May 2016 Contribution Agreement contained customary representations and warranties and indemnification by SPLC. In connection with the May 2016 Acquisition we acquired book value of net assets under common control as follows: Cost investment (1) $ 5.2 Equity method investments (2) 1.5 Partner's capital (3) 87.0 May 2016 Acquisition $ 93.7 (1) Book value of 3.0% additional interest in Colonial contributed by SPLC. (2) Book value of 1.0% additional interest in Bengal contributed by SPLC. (3) Book value of 30.0% additional interest in Zydeco from SPLC’s noncontrolling interest. We recognized $606.3 million of consideration in excess of the book value of net assets acquired as a capital distribution to our general partner in accordance with our policy for common control transactions. This capital distribution was comprised of $599.2 million in cash and $7.1 million in general partner units issued.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 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 See the description of the May 2017 Purchase and Sale Agreement related to the May 2017 Acquisition and the April 2017 Pipeline Sale and Purchase Agreement related to the April 2017 Divestiture as further described in Note 2—Acquisitions and Divestitures. For a discussion of all other 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 our initial public offering (“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. Under the Omnibus Agreement, SPLC indemnified us against certain enumerated risks. Of those indemnity obligations, two remain. First, SPLC agreed to be responsible for unknown environmental liabilities arising out of the ownership and operation of our initial assets prior to the closing of the IPO, to the extent identified before November 3, 2017. SPLC's indemnification of us against these environmental liabilities and certain other liabilities is subject to an aggregate limit of $15.0 million , of which $10.7 million remains. Second, SPLC agreed to indemnify us against tax liabilities relating to our initial assets that are identified prior to the date that is 60 days after the expiration of the statute of limitations applicable to such liabilities. This obligation has no threshold or cap. We in turn agreed to indemnify SPLC against events and conditions associated with the ownership or operation of our initial assets (other than any liabilities against which SPLC is specifically required to indemnify us as described above). During the nine months ended September 30, 2017 , neither we nor SPLC made 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 September 30, 2017 and December 31, 2016 . Noncontrolling interest was 57.0% at the time of IPO, decreased to 37.5% with the May 2015 Acquisition, and further decreased to 7.5% with the May 2016 Acquisition. Other Related Party Balances Other related party balances consist of the following: September 30, 2017 December 31, 2016 Accounts receivable $ 16.2 $ 12.1 Prepaid expenses 0.6 3.2 Other assets 0.7 — Accounts payable (1) 10.5 5.4 Deferred revenue 20.8 7.9 Accrued liabilities (2) 5.9 5.1 Debt payable (3) 1,000.6 686.0 Lease liability (4) — 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 September 30, 2017 , accrued liabilities reflects $ 5.5 million accrued interest and $ 0.4 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 $1.3 million and $0.9 million as of September 30, 2017 and December 31, 2016 , respectively. (4) As part of the Motiva JV separation effective May 2017, Motiva is no longer a related party. As of September 30, 2017, this is a third-party balance. Related Party Credit Facilities We have entered into three credit facilities with Shell Treasury Center West (“STCW”), an affiliate of Shell: the Five Year Revolver, the Five Year Fixed Facility and the 364 -Day Revolver. The 364 -Day Revolver expired as of March 1, 2017, and has not been replaced. Zydeco has also entered into the Zydeco Revolver with STCW. For definitions and additional information regarding these credit facilities, see Note 7—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 $28.6 million and $77.9 million for the three and nine months ended September 30, 2017 , respectively, and $25.8 million and $79.5 million for the three and nine months ended September 30, 2016 , respectively. Storage revenues from related parties were $1.2 million and $4.6 million for the three and nine months ended September 30, 2017 , respectively, and $2.3 million and $6.5 million for the three and nine months ended September 30, 2016 , respectively. Additionally, we have certain transportation services agreements with a related party that are considered operating leases under GAAP and are recorded within Lease revenue - related parties in the condensed consolidated statement of income. Lease revenues from related parties were $11.7 million and $19.4 million for the three and nine months ended September 30, 2017 , respectively, and zero for both the three and nine months ended September 30, 2016 . These agreements were each entered into for terms of ten years , with the option to extend for two additional five year terms. As of September 30, 2017 , future minimum payments to be received under the ten year contract term of these agreements were estimated to be: Total Less than 1 year Years 2 to 3 Years 4 to 5 More than 5 years Operating leases $ 443.6 $ 46.3 $ 92.6 $ 92.6 $ 212.1 During the three and nine months ended September 30, 2017 , we converted excess allowance oil to cash through sales to affiliates of Shell and recognized a gain of $0.1 million and $0.8 million , respectively, and for the three and nine months ended September 30, 2016 , we recognized a gain of $0.3 million and $0.8 million , respectively, from such sales in Operations and maintenance expense. During the three and nine months ended September 30, 2017, Zydeco, Bengal, Odyssey, Mars, Poseidon, Proteus, Endymion, Colonial, Explorer and Cleopatra paid cash distributions to us of $71.4 million and $249.1 million , of which $24.1 million and $105.5 million related to Zydeco. During the three and nine months ended September 30, 2016 , Zydeco, Bengal, Mars, Poseidon, Colonial and Explorer paid cash distributions to us of $63.9 million and $174.8 million , of which $35.1 million and $80.7 million related to Zydeco. During the three and nine months ended September 30, 2017 , we were allocated $3.4 million and $8.4 million , respectively, and during the three and nine months ended September 30, 2016 , we were allocated $2.3 million and $7.8 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. As a result, we are not allocated corporate expenses from SPLC or Shell, but are allocated direct expenses and our proportionate share of field and regional expenses, including payroll expenses not covered under the Management Agreement. Beginning October 1, 2015, Pecten entered into an operating and management agreement under which we are not allocated corporate expenses from SPLC or Shell, but are allocated direct expenses and our proportionate share of field and regional expenses from SPLC. Beginning May 10, 2017, Sand Dollar entered into an operating and management agreement under which we are not allocated corporate expenses from SPLC or Shell, but are allocated direct expenses and our proportionate share of 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. The majority of our insurance coverage is provided by a wholly owned subsidiary of Shell with the remaining coverage provided by third-party insurers. The related party portion of insurance expense for the three and nine months ended September 30, 2017 was $2.1 million and $5.1 million , respectively, and for the three and nine months ended September 30, 2016 , was $1.2 million and $4.2 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 September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Operations and maintenance - related parties $ 8.4 $ 7.5 $ 26.6 $ 22.6 General and administrative - related parties (1) 8.6 7.4 25.2 22.3 (1) For the three and nine months ended September 30, 2017 , we incurred $2.1 million and $6.1 million under the Management Agreement and $2.2 million and $6.4 million under the Omnibus Agreement for the general and administrative fee. For the three and nine months ended September 30, 2016 we incurred $1.9 million and $5.8 million under the Management Agreement and $2.2 million and $6.4 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 and nine months ended September 30, 2017 were $1.2 million and $2.9 million , respectively, and for the three and nine months ended September 30, 2016 were $0.9 million and $2.6 million , respectively. Our share of defined contribution benefit plan costs for the three and nine months ended September 30, 2017 were $0.5 million and $1.1 million , respectively and for the three and nine months ended September 30, 2016 were $0.4 million and $1.1 million , respectively. 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 4 – Equity Method Investments for additional details. Reimbursements from Our General Partner During the three and nine months ended September 30, 2017 , we filed claims for reimbursement from our Parent of $3.1 million and $13.6 million , respectively. This reflects our proportionate share of Zydeco directional drill project costs and expenses of $2.2 million and $12.1 million , respectively, for the three and nine months ended September 30, 2017 . Additionally, this includes reimbursement for the Refinery Gas Pipeline gas to butane service conversion project of $0.9 million and $1.5 million for the three and nine months ended September 30, 2017 , respectively. During the three and nine months ended September 30, 2016 , we received reimbursement from our Parent for our proportionate share of Zydeco directional drill costs and expenses of $0.1 million and $0.4 million , respectively, as well as reimbursement for certain costs and expenses incurred by Pecten for storm water improvements at Lockport of $1.0 million and $1.2 million , respectively. These reimbursements are treated as a capital contribution from our general partner.

Equity Method Investments

Equity Method Investments	9 Months Ended
	Sep. 30, 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: September 30, 2017 December 31, 2016 Ownership Investment Amount Ownership Investment Amount Bengal 50.0% $ 78.2 50.0% $ 76.1 Odyssey 49.0% 3.6 49.0% 3.0 Mars 48.6% 129.7 48.6% 130.2 Poseidon 36.0% 4.8 36.0% 13.2 Proteus 10.0% 17.6 10.0% 19.1 Endymion 10.0% 19.9 10.0% 20.8 $ 253.8 $ 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 September 30, 2017 and December 31, 2016 , the unamortized basis differences included in our equity investments are $28.4 million and $30.9 million , respectively. For the three and nine months ended September 30, 2017 , the net amortization expense was $0.7 million and $2.1 million , respectively. For the three and nine months ended September 30, 2016, the net amortization expense was $0.3 million and $1.1 million , respectively. Our equity investments in affiliates balance was affected by the following during the periods indicated: Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 Distributions Received Income from Equity Investments Purchase Price Adjustment Distributions received Income from Equity investments Purchase Price Adjustment Bengal $ 5.5 $ 6.2 $ — $ 14.8 $ 16.9 $ — Odyssey 4.4 5.0 — 13.1 13.7 — Mars 21.9 22.0 — 64.2 63.7 — Poseidon 9.6 7.3 — 28.9 20.5 — Proteus 0.6 0.3 — 2.3 1.1 0.3 Endymion 0.5 0.4 — 2.0 1.2 0.1 $ 42.5 $ 41.2 — $ 125.3 $ 117.1 $ 0.4 Three Months Ended September 30, 2016 Nine Months Ended September 30, 2016 Distributions Received Income from Equity Investments Distributions Received Income from Equity Investments Bengal $ 2.7 $ 5.2 $ 16.1 $ 15.9 Mars 11.5 8.6 34.5 31.7 Poseidon 10.5 7.6 31.9 22.6 $ 24.7 $ 21.4 $ 82.5 $ 70.2 The following tables present aggregated selected unaudited income statement data for our equity method investments (on a 100% basis): Three Months Ended September 30, 2017 Total Revenues Total Operating Expenses Operating Income Net Income Statements of Income Bengal $ 18.7 $ 6.8 $ 11.9 $ 11.9 Odyssey 11.1 1.0 10.1 10.1 Mars 66.0 19.5 46.5 46.5 Poseidon 30.6 8.2 22.4 20.7 Proteus 7.6 2.9 4.7 4.4 Endymion 8.2 3.3 4.9 4.9 Nine Months Ended September 30, 2017 Total Revenues Total Operating Expenses Operating Income Net Income Statements of Income Bengal $ 54.6 $ 21.1 $ 33.5 $ 33.4 Odyssey 30.8 3.0 27.8 27.8 Mars 197.3 63.7 133.6 133.6 Poseidon 88.0 24.8 63.2 58.7 Proteus 22.8 9.0 13.8 12.9 Endymion 25.3 9.6 15.7 14.9 Three Months Ended September 30, 2016 Total Revenues Total Operating Expenses Operating Income Net Income Statements of Income Bengal $ 17.3 $ 7.2 $ 10.1 $ 10.3 Mars 54.0 23.1 30.9 30.9 Poseidon 31.3 8.2 23.1 22.0 Nine Months Ended September 30, 2016 Total Revenues Total Operating Expenses Operating Income Net Income Statements of Income Bengal $ 52.3 $ 20.7 $ 31.6 $ 31.7 Mars 175.5 62.1 113.4 113.4 Poseidon 90.7 22.5 68.2 64.7 The difference between operating income and net income represents interest expense or interest income.

Property, Plant and Equipment

Property, Plant and Equipment	9 Months Ended
	Sep. 30, 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 September 30, 2017 December 31, 2016 Land — $ 2.0 $ 2.0 Building and improvements 10 - 40 years 37.0 29.6 Pipeline and equipment (1) 10 - 30 years 888.2 895.7 Other 5 - 25 years 15.5 16.9 942.7 944.2 Accumulated depreciation and amortization (2) (368.1 ) (354.8 ) 574.6 589.4 Construction in progress 34.3 21.2 Property, plant and equipment, net $ 608.9 $ 610.6 (1) As of September 30, 2017 , includes cost of $163.4 million related to assets under operating lease (as lessor), which commenced in May 2017 . As of September 30, 2017 and December 31, 2016, includes cost of $22.8 million related to assets under capital lease (as lessee). (2) As of September 30, 2017 , includes accumulated depreciation of $32.1 million related to assets under operating lease (as lessor), which commenced in May 2017. As of September 30, 2017 and December 31, 2016, includes accumulated depreciation of $2.7 million and $1.6 million , respectively, related to assets under capital lease (as lessee). Depreciation and amortization expense on property, plant and equipment for the three and nine months ended September 30, 2017 was $8.9 million and $28.0 million , respectively, and for the three and nine months ended September 30, 2016 was $9.1 million and $27.1 million , respectively. Depreciation and amortization expense 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 operating and capital leases.

Accrued Liabilities - Third Par

Accrued Liabilities - Third Parties	9 Months Ended
	Sep. 30, 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: September 30, 2017 December 31, 2016 Transportation, project engineering $ 7.8 $ 4.2 Property taxes 7.2 0.6 Professional fees 0.5 0.3 Other accrued liabilities 1.7 1.8 Accrued liabilities - third parties $ 17.2 $ 6.9 For a discussion of accrued liabilities - related parties, see Note 3—Related Party Transactions .

Related Party Debt

Related Party Debt	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Related Party Debt	Related Party Debt Consolidated related party debt obligations comprise the following as of the dates indicated: September 30, 2017 December 31, 2016 Five Year Fixed Facility, fixed rate, due March 1, 2022 (1) $ 506.9 $ — Five Year Revolver, variable rate, due October 31, 2019 (2) 495.0 686.9 Zydeco Revolver, variable rate, due August 6, 2019 (3) — — 364-Day Revolver, variable rate, expired March 1, 2017 (4) — — Unamortized debt issuance costs (1.3 ) (0.9 ) Debt payable – related party $ 1,000.6 $ 686.0 (1) As of September 30, 2017 , availability under the $600.0 million Five Year Fixed Facility was $93.1 million . (2) As of September 30, 2017 , availability under the $760.0 million Five Year Revolver was $265.0 million . (3) As of September 30, 2017 , the entire $30.0 million capacity was available under the Zydeco Revolver. (4) The 364 -Day Revolver expired March 1, 2017. For three and nine months ended September 30, 2017 , interest and fee expenses associated with our borrowings were $9.1 million and $19.8 million , respectively. For three and nine months ended September 30, 2016 , interest and fee expenses associated with our borrowings were $2.0 million and $5.0 million , respectively. Borrowings under our Five Year Revolver (as defined below) approximate fair value as the interest rates are variable and reflective of market rates, which results in a Level 2 instrument. The fair value of our Five Year Fixed Facility (as defined below) is estimated based on the published market prices for issuances of similar risk and tenor and is categorized as a Level 2 instrument. As of September 30, 2017 , the carrying amount and estimated fair value of total debt (before amortization of issuance costs) was $1,001.9 million and $1,017.7 million , respectively. On September 15, 2017, we used net proceeds from sales of common units to third parties to repay $265.0 million of borrowings outstanding under our Five Year Revolver. On May 10, 2017, we funded the May 2017 Acquisition with $50.0 million of cash on hand, $73.1 million in borrowings under our Five Year Revolver and $506.9 million in borrowings under our Five Year Fixed Facility (as defined below). On May 23, 2016, we partially funded the cash portion of the May 2016 Acquisition with $296.7 million in borrowings under our Five Year Revolver. 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 and all $ 137.4 million of borrowings outstanding under the 364 -Day Revolver. 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 that 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 . 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 nine months ended September 30, 2017 , the weighted average interest rate for the Five Year Revolver was 2.4% . 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. Borrowings under the credit facility bear interest at the three-month LIBOR rate plus a margin. As of September 30, 2017 , the interest rate for the Zydeco Revolver was 2.8% . The Zydeco Revolver also requires payment of customary fees, including issuance and commitment fees. The Zydeco Revolver matures on August 6, 2019. Covenants Under the Five Year Fixed Facility, Five Year Revolver and Zydeco Revolver, we (and Zydeco in the case of the Zydeco Revolver) have, among other things: • agreed to restrict additional indebtedness not loaned by STCW; • to give the applicable facility pari passu ranking with any new indebtedness; and • to refrain from securing our assets except as agreed with STCW ( Five Year Fixed Facility only). The facilities also contain customary events of default, such as nonpayment of principal, interest and fees when due and violation of covenants, as well as cross-default provisions under which a default under one credit facility may trigger an event of default in another facility with the same borrower. 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 September 30, 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	9 Months Ended
	Sep. 30, 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 September 30, 2017, we completed the sale of 5,200,000 common units under this program for $139.8 million net proceeds ( $140.2 million gross proceeds, or an average price of $26.96 per common unit, less $0.4 million of transaction fees). In connection with the issuance of the common units, we issued 106,122 general partner units to our general partner for $2.9 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 for general partnership purposes. During the quarter ended June 30, 2017, we completed the sale of 94,925 common units under this program for $2.9 million net proceeds ( $3.0 million gross proceeds, or an average price of $31.51 per common unit, less $0.1 million of transaction fees). In connection with the issuance of the common units, we issued 1,938 general partner units to our general partner for $0.1 million in order to maintain its 2.0% general partner interest in us. We used proceeds from these sales of common units and from our general partner's proportionate capital contribution for general partnership purposes. 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. Other than as described above, we did not have any sales under this program. Public Offerings On September 15, 2017, we completed the sale of 5,170,000 common units in a registered public offering for $135.2 million net proceeds. In connection with the issuance of common units, we issued 105,510 general partner units to our general partner for $2.8 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 for general partnership purposes. 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. On May 23, 2016, in conjunction with the May 2016 Acquisition, we completed the sale of 10,500,000 common units in a registered public offering (the “May 2016 Offering”) for $345.8 million net proceeds ( $349.1 million gross proceeds, or $ 33.25 per common unit, less $2.9 million of underwriter's fees and $0.4 million of transaction fees). In connection with the issuance of common units, we issued 214,285 general partner units to our general partner as non-cash consideration of $7.1 million in order to maintain its 2.0% general partner interest in us. We used the net proceeds from the May 2016 Offering and from our general partner's proportionate capital contribution to partially fund the May 2016 Acquisition. As part of the registered public offering on May 23, 2016, the underwriters received an option to purchase an additional 1,575,000 common units, which they exercised in full on June 9, 2016 for $51.8 million net proceeds ( $52.4 million gross proceeds, or $33.25 per common unit, less $0.5 million in underwriter's fees and $0.1 million of transaction fees). In connection with this issuance of common units, we issued 32,143 general partner units to our general partner for $1.1 million in order to maintain its 2.0% general partner interest in us. Units Outstanding As of September 30, 2017 , we had 187,782,369 common units outstanding, of which 98,832,233 were publicly owned. SPLC owned 88,950,136 common units, representing an aggregate 46.4% limited partner interest in us, all of the incentive distribution rights, and 3,832,293 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 September 30, 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 ) — — Units issued in connection with ATM program 5,294,925 — — 108,060 5,402,985 Units issued in connection with public offering 5,170,000 — — 105,510 5,275,510 Balance as of September 30, 2017 98,832,233 88,950,136 — 3,832,293 191,614,662 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 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 $ 13.9 $ 4.7 $ 14.8 $ 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 25.7 25.9 — 10.7 1.3 63.6 0.29100 August 14, 2017 June 30, 2017 26.9 27.0 — 12.9 1.4 68.2 0.30410 November 14, 2017 September 30, 2017 (1) 31.4 28.3 — 16.2 1.5 77.4 0.31800 (1) For more information see Note 12 — Subsequent Events . Distributions to Noncontrolling Interest Distributions to SPLC for its noncontrolling interest in Zydeco for the three and nine months ended September 30, 2017 were $2.0 million and $8.6 million , respectively, and for the three and nine months ended September 30, 2016 were $2.7 million and $17.1 million , respectively. See Note 3—Related Party Transactions for additional details.

Net Income Per Limited Partner

Net Income Per Limited Partner Unit	9 Months Ended
	Sep. 30, 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. Our net income includes earnings related to businesses acquired through transactions between entities under common control for periods prior to their acquisition by us. We have allocated these pre-acquisition earnings to our Parent. 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 Nine Months Ended 2017 2016 2017 2016 Net income $ 74.5 $ 61.8 $ 218.2 $ 204.5 Less: Net income attributable to Parent — 3.0 3.0 11.4 Net income attributable to noncontrolling interests 1.9 2.5 6.3 17.7 Net income attributable to the Partnership 72.6 56.3 208.9 175.4 Less: General Partner's distribution declared 17.7 7.1 44.0 14.7 Limited Partners' distribution declared on common units 59.7 29.0 165.2 79.4 Limited Partners' distribution declared on subordinated units — 17.8 — 50.5 Income (less than) / in excess of distributions $ (4.8 ) $ 2.4 $ (0.3 ) $ 30.8 Three Months Ended September 30, 2017 General Partner Limited Partners' Common Units Total (in millions of dollars, except per unit data) Distributions declared $ 17.7 $ 59.7 $ 77.4 Distributions in excess of income (0.1 ) (4.7 ) (4.8 ) Net income attributable to the Partnership $ 17.6 $ 55.0 $ 72.6 Weighted average units outstanding (in millions) (1) : Basic and diluted 179.2 Net income per Limited Partner Unit (in dollars): Basic and diluted $ 0.31 Nine Months Ended September 30, 2017 General Partner Limited Partners' Common Units Total (in millions of dollars, except per unit data) Distributions declared $ 44.0 $ 165.2 $ 209.2 Distributions in excess of income — (0.3 ) (0.3 ) Net income attributable to the Partnership $ 44.0 $ 164.9 $ 208.9 Weighted average units outstanding (in millions) (1) : Basic and diluted 178.0 Net income per Limited Partner Unit (in dollars): Basic and diluted $ 0.93 (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 September 30, 2016 General Partner Limited Partners' Common Units Limited Partners' Subordinated Units Total (in millions of dollars, except per unit data) Distributions declared $ 7.1 $ 29.0 $ 17.8 $ 53.9 Income in excess of distributions 0.1 1.4 0.9 2.4 Net income attributable to the Partnership $ 7.2 $ 30.4 $ 18.7 $ 56.3 Weighted average units outstanding (in millions): Basic and diluted 109.8 67.5 Net income per Limited Partner Unit (in dollars): Basic and diluted $ 0.28 $ 0.28 Nine Months Ended September 30, 2016 General Partner Limited Partners' Common Units Limited Partners' Subordinated Units Total (in millions of dollars, except per unit data) Distributions declared $ 14.7 $ 79.4 $ 50.5 $ 144.6 Income in excess of distributions 0.6 18.0 12.2 30.8 Net income attributable to the Partnership $ 15.3 $ 97.4 $ 62.7 $ 175.4 Weighted average units outstanding (in millions): Basic and diluted 99.2 67.5 Net income per Limited Partner Unit (in dollars): Basic and diluted $ 0.98 $ 0.93

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 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 and nine months ended September 30, 2017 and 2016 was immaterial.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 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 September 30, 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 3 - 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. There was no FERC indexing adjustment to this rate effective July 1, 2017. 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	9 Months Ended
	Sep. 30, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events We have evaluated events that have occurred after September 30, 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 condensed consolidated financial statements and accompanying notes. Distribution On October 18, 2017 , the Board declared a cash distribution of $0.3180 per limited partner unit for the three months ended September 30, 2017 . The distribution will be paid on November 14, 2017 to unitholders of record as of October 31, 2017 . October 2017 Acquisition On October 17, 2017, we acquired a 50.0% interest in Crestwood Permian Basin LLC (“Permian Basin LLC”), which owns the Nautilus gathering system in the Permian Basin, for $49.9 million in consideration and initial capital contributions (the “October 2017 Acquisition”). The October 2017 Acquisition closed pursuant to a Member Interest Purchase Agreement dated October 16, 2017 (the “October 2017 Purchase Agreement”), among the Operating Company and CPB Member LLC (a jointly owned subsidiary of Crestwood Equity Partners LP and First Reserve). We funded the October 2017 Acquisition with cash on hand.

Description of Business and B19

Description of Business and Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 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 well as interests in entities that own natural gas and refinery gas pipelines which transport offshore natural gas to market hubs and deliver refinery gas from refineries and plants to chemical sites along the Gulf Coast.
Basis of Presentation	Basis of Presentation Our condensed consolidated financial statements include all 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. 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 and nine months ended September 30, 2017 and 2016 include all adjustments we believe are necessary for a fair statement of the results for the interim periods presented. These adjustments are of a normal recurring nature unless otherwise disclosed. Operating results for the interim periods 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. The acquisition of Delta, Na Kika and Refinery Gas Pipeline (the “Shell Delta, Na Kika and Refinery Gas Pipeline Operations” or “Delta, Na Kika and Refinery Gas Pipeline”) was a transfer of businesses between entities under common control, which requires it to be accounted for as if the transfer had occurred at the beginning of the period of transfer, with prior periods retrospectively adjusted to furnish comparative financial information. Accordingly, the accompanying financial statements and notes have been retrospectively adjusted to include the historical results and financial position of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations prior to the effective date of the acquisition. See Note 2 - Acquisitions and Divestitures for additional information.
Revenue Recognition	Revenue Recognition Certain transportation services agreements with a related party are considered operating leases under GAAP. Revenues from these agreements are recorded within Lease revenue - related parties in the condensed consolidated statements of income. See Note 3-Related Party Transactions for additional information.
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 ASU'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 will adopt the requirements of the new standard in the first quarter of 2018 under the modified retrospective transition method. As part of our implementation efforts to date, all of our revenue contracts have been subject to review to evaluate the effect of the new standard on our revenue recognition practices. We have also made progress in evaluating new disclosure requirements and identifying impacts to our business processes, systems and controls to support recognition and disclosure under the new guidance. We expect the adoption of the new standard will change the way we recognize revenue from our committed shippers under transportation services agreements. We anticipate the new standard will result in earlier recognition of revenue related to cash collected from customers for shortfalls under these agreements, which is recorded as deferred revenue. We currently recognize deferred revenue under these arrangements into revenue once all contingencies or potential performance obligations associated with the related volumes have been satisfied or expired. Upon adoption of the new standard and application of the breakage model to our deferred revenue, we anticipate a cumulative transition adjustment resulting from the earlier recognition of revenue with a corresponding adjustment to beginning retained earnings and are in the process of quantifying the impact. We have also identified potential contracts or elements of contracts that may require a change in presentation on our income statement, specifically related to the service component of leases, product loss allowance, gross versus net presentation and reimbursements of capital expenditures. Currently, we do not anticipate these to materially impact our financial statements as there will be no net impact to income before taxes. However, this is still under review and subject to our ongoing assessment of the guidance. For additional information on accounting pronouncements issued prior to September 2017, refer to Note 2—Summary of Significant Accounting Policies in the Notes to Consolidated Financial Statements of our 2016 Annual Report.

Description of Business and B20

Description of Business and Basis of Presentation (Tables)	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Ownership Percentage	The following table reflects our ownership, and Shell's retained ownership as of September 30, 2017 . SHLX Ownership Shell's Retained Ownership Pecten Midstream LLC (“Pecten”) 100.0 % — Sand Dollar Pipeline LLC (“Sand Dollar”) 100.0 % — Zydeco Pipeline Company LLC (“Zydeco”) 92.5 % 7.5 % Bengal Pipeline Company LLC (“Bengal”) 50.0 % — Odyssey Pipeline LLC (“Odyssey”) 49.0 % 22.0 % Mars Oil Pipeline Company LLC (“Mars”) 48.6 % 22.9 % Poseidon Oil Pipeline Company LLC (“Poseidon”) 36.0 % — Proteus Oil Pipeline Company, LLC (“Proteus”) 10.0 % — Endymion Oil Pipeline Company, LLC (“Endymion”) 10.0 % — Colonial Pipeline Company (“Colonial”) 6.0 % 10.12 % Explorer Pipeline Company (“Explorer”) 2.62 % 35.97 % Cleopatra Gas Gathering Company, LLC (“Cleopatra”) 1.0 % —

Acquisitions and Divestitures (

Acquisitions and Divestitures (Tables)	9 Months Ended
	Sep. 30, 2017
Business Combinations [Abstract]
Schedule of Acquired Book Value of Net Assets Under Common Control	In connection with the May 2016 Acquisition we acquired book value of net assets under common control as follows: Cost investment (1) $ 5.2 Equity method investments (2) 1.5 Partner's capital (3) 87.0 May 2016 Acquisition $ 93.7 (1) Book value of 3.0% additional interest in Colonial contributed by SPLC. (2) Book value of 1.0% additional interest in Bengal contributed by SPLC. (3) Book value of 30.0% additional interest in Zydeco from SPLC’s noncontrolling interest. In connection with the May 2017 Acquisition we acquired historical carrying value of property, plant and equipment, net and other assets under common control as follows: Delta $ 40.1 Na Kika 26.0 Refinery Gas Pipeline 134.6 May 2017 Acquisition $ 200.7
Schedule of Business Acquisitions	The following tables present our financial position and our results of operations and of cash flows giving effect to the May 2017 Acquisition of the Delta, Na Kika and Refinery Gas Pipeline Operations. The results of Delta, Na Kika and Refinery Gas Pipeline prior to the closing date of the acquisition are included in “Delta, Na Kika and Refinery Gas Pipeline Operations” and the consolidated results are included in “Consolidated Results” within the tables below: December 31, 2016 Shell Midstream Partners, L.P. (1) Delta, Na Kika and Refinery Gas Pipeline Operations (2) Consolidated Results ASSETS Current assets Cash and cash equivalents $ 121.9 $ — $ 121.9 Accounts receivable – third parties, net 18.4 2.4 20.8 Accounts receivable – related parties 10.1 2.0 12.1 Allowance oil 9.0 2.7 11.7 Prepaid expenses 6.0 0.5 6.5 Total current assets 165.4 7.6 173.0 Equity method investments 262.4 — 262.4 Property, plant and equipment, net 398.0 212.6 610.6 Cost investments 39.8 — 39.8 Other assets — 0.6 0.6 Total assets $ 865.6 $ 220.8 $ 1,086.4 LIABILITIES Current liabilities Accounts payable – third parties $ 1.5 $ 2.6 $ 4.1 Accounts payable – related parties 5.2 0.2 5.4 Deferred revenue – third parties 6.0 — 6.0 Deferred revenue – related parties 7.9 — 7.9 Accrued liabilities – third parties 5.6 1.3 6.9 Accrued liabilities – related parties 5.1 — 5.1 Total current liabilities 31.3 4.1 35.4 Noncurrent liabilities Debt payable – related party 686.0 — 686.0 Lease liability – related party 24.9 — 24.9 Asset retirement obligations 1.4 — 1.4 Other unearned income 2.1 — 2.1 Total noncurrent liabilities 714.4 — 714.4 Total liabilities 745.7 4.1 749.8 Commitments and Contingencies (Note 11) EQUITY Common unitholders – public 2,485.7 — 2,485.7 Common unitholder – SPLC (124.1 ) — (124.1 ) Subordinated unitholder (389.6 ) — (389.6 ) General partner – SPLC (1,873.7 ) — (1,873.7 ) Total partners' capital 98.3 — 98.3 Noncontrolling interest 21.6 — 21.6 Net parent investment — 216.7 216.7 Total equity 119.9 216.7 336.6 Total liabilities and equity $ 865.6 $ 220.8 $ 1,086.4 (1) As previously reported in our Annual Report on Form 10-K for 2016. (2) The financial position of the Delta, Na Kika and Refinery Gas Pipeline Operations as of December 31, 2016. Three Months Ended September 30, 2016 Shell Midstream Partners, L.P. (1) Delta, Na Kika and Refinery Gas Pipeline Operations (2) Consolidated Results Revenue Third parties $ 46.1 $ 7.7 $ 53.8 Related parties 21.8 6.3 28.1 Total revenue 67.9 14.0 81.9 Costs and expenses Operations and maintenance – third parties 11.4 2.7 14.1 Operations and maintenance – related parties 5.3 2.2 7.5 General and administrative – third parties 2.2 — 2.2 General and administrative – related parties 5.7 1.7 7.4 Depreciation, amortization and accretion 6.0 3.1 9.1 Property and other taxes 1.3 1.3 2.6 Total costs and expenses 31.9 11.0 42.9 Operating income 36.0 3.0 39.0 Income from equity investments 21.4 — 21.4 Dividend income from cost investments 4.2 — 4.2 Investment and dividend income 25.6 — 25.6 Interest expense, net 2.8 — 2.8 Income before income taxes 58.8 3.0 61.8 Income tax expense — — — Net income 58.8 3.0 61.8 Less: Net income attributable to Parent — 3.0 3.0 Less: Net income attributable to noncontrolling interests 2.5 — 2.5 Net income attributable to the Partnership $ 56.3 $ — $ 56.3 (1) As previously reported in our Quarterly Report on Form 10-Q for the quarterly period ended September 30, 2016. (2) Our Parents' results of the Delta, Na Kika and Refinery Gas Pipeline Operations from July 1, 2016 through September 30, 2016. Nine Months Ended September 30, 2016 Shell Midstream Partners, L.P. (1) Delta, Na Kika and Refinery Gas Pipeline Operations (2) Consolidated Results Revenue Third parties $ 149.8 $ 25.1 $ 174.9 Related parties 65.9 20.1 86.0 Total revenue 215.7 45.2 260.9 Costs and expenses Operations and maintenance – third parties 33.1 8.6 41.7 Operations and maintenance – related parties 15.9 6.7 22.6 General and administrative – third parties 6.2 0.2 6.4 General and administrative – related parties 17.3 5.0 22.3 Depreciation, amortization and accretion 17.7 9.4 27.1 Property and other taxes 6.4 3.9 10.3 Total costs and expenses 96.6 33.8 130.4 Operating income 119.1 11.4 130.5 Income from equity investments 70.2 — 70.2 Dividend income from cost investments 11.6 — 11.6 Investment and dividend income 81.8 — 81.8 Interest expense, net 7.8 — 7.8 Income before income taxes 193.1 11.4 204.5 Income tax expense — — — Net income 193.1 11.4 204.5 Less: Net income attributable to Parent — 11.4 11.4 Less: Net income attributable to noncontrolling interests 17.7 — 17.7 Net income attributable to the Partnership $ 175.4 $ — $ 175.4 (1) As previously reported in our Quarterly Report on Form 10-Q for the nine month period ended September 30, 2016. (2) Our Parents' results of the Delta, Na Kika and Refinery Gas Pipeline Operations from January 1, 2016 through September 30, 2016. Nine Months Ended September 30, 2016 Shell Midstream Partners, L.P. (1) Delta, Na Kika and Refinery Gas Pipeline Operations (2) Consolidated Results Cash flows from operating activities Net income $ 193.1 $ 11.4 $ 204.5 Adjustments to reconcile net income to net cash provided by operating activities Depreciation, amortization and accretion 17.7 9.4 27.1 Non-cash interest expense 0.2 — 0.2 Undistributed equity earnings 2.7 — 2.7 Changes in operating assets and liabilities Accounts receivable 6.6 0.7 7.3 Allowance oil (3.6 ) (0.2 ) (3.8 ) Prepaid expenses 4.3 0.7 5.0 Accounts payable (1.6 ) (0.7 ) (2.3 ) Deferred revenue (0.4 ) — (0.4 ) Accrued liabilities 5.1 3.1 8.2 Net cash provided by operating activities 224.1 24.4 248.5 Cash flows from investing activities Capital expenditures (21.3 ) (7.5 ) (28.8 ) Acquisitions (120.0 ) — (120.0 ) Return of investment 9.6 — 9.6 Net cash used in investing activities (131.7 ) (7.5 ) (139.2 ) Cash flows from financing activities Net proceeds from public offerings 818.1 — 818.1 Borrowing under credit facility 296.7 — 296.7 Contributions from general partner 9.8 — 9.8 Repayment of credit facilities (410.0 ) — (410.0 ) Capital distributions to general partner (599.2 ) — (599.2 ) Distributions to noncontrolling interest (17.1 ) — (17.1 ) Distributions to unitholders and general partner (126.0 ) — (126.0 ) Net distributions to Parent — (16.9 ) (16.9 ) Other contribution from Parent 3.1 — 3.1 Net cash used in financing activities (24.6 ) (16.9 ) (41.5 ) Net increase in cash and cash equivalents 67.8 — 67.8 Cash and cash equivalents at beginning of the period 93.0 — 93.0 Cash and cash equivalents at end of the period $ 160.8 $ — $ 160.8 Supplemental Cash Flow Information Non-cash investing and financing transactions Change in accrued capital expenditures $ (1.1 ) $ (4.2 ) $ (5.3 ) Other non-cash contributions from Parent 0.3 — 0.3 Other non-cash capital distributions to general partner (7.1 ) — (7.1 ) Other non-cash contribution from general partner 7.1 — 7.1 Other non-cash credit facilities issuance costs (0.6 ) — (0.6 ) (1) As previously reported in our Quarterly Report on Form 10-Q for the nine month period ended September 30, 2016. (2) Our Parents' results of the Delta, Na Kika and Refinery Gas Pipeline Operations from January 1, 2016 through September 30, 2016.

Related Party Transactions (Tab

Related Party Transactions (Tables)	9 Months Ended
	Sep. 30, 2017
Related Party Transactions [Abstract]
Schedule of Other Related Party Balances	Other related party balances consist of the following: September 30, 2017 December 31, 2016 Accounts receivable $ 16.2 $ 12.1 Prepaid expenses 0.6 3.2 Other assets 0.7 — Accounts payable (1) 10.5 5.4 Deferred revenue 20.8 7.9 Accrued liabilities (2) 5.9 5.1 Debt payable (3) 1,000.6 686.0 Lease liability (4) — 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 September 30, 2017 , accrued liabilities reflects $ 5.5 million accrued interest and $ 0.4 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 $1.3 million and $0.9 million as of September 30, 2017 and December 31, 2016 , respectively. (4) As part of the Motiva JV separation effective May 2017, Motiva is no longer a related party. As of September 30, 2017, this is a third-party balance.
Schedule of Future Minimum Payments To Be Received	As of September 30, 2017 , future minimum payments to be received under the ten year contract term of these agreements were estimated to be: Total Less than 1 year Years 2 to 3 Years 4 to 5 More than 5 years Operating leases $ 443.6 $ 46.3 $ 92.6 $ 92.6 $ 212.1
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 September 30, Nine Months Ended September 30, 2017 2016 2017 2016 Operations and maintenance - related parties $ 8.4 $ 7.5 $ 26.6 $ 22.6 General and administrative - related parties (1) 8.6 7.4 25.2 22.3 (1) For the three and nine months ended September 30, 2017 , we incurred $2.1 million and $6.1 million under the Management Agreement and $2.2 million and $6.4 million under the Omnibus Agreement for the general and administrative fee. For the three and nine months ended September 30, 2016 we incurred $1.9 million and $5.8 million under the Management Agreement and $2.2 million and $6.4 million under the Omnibus Agreement for the general and administrative fee.

Equity Method Investments (Tabl

Equity Method Investments (Tables)	9 Months Ended
	Sep. 30, 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: September 30, 2017 December 31, 2016 Ownership Investment Amount Ownership Investment Amount Bengal 50.0% $ 78.2 50.0% $ 76.1 Odyssey 49.0% 3.6 49.0% 3.0 Mars 48.6% 129.7 48.6% 130.2 Poseidon 36.0% 4.8 36.0% 13.2 Proteus 10.0% 17.6 10.0% 19.1 Endymion 10.0% 19.9 10.0% 20.8 $ 253.8 $ 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 September 30, 2017 Nine Months Ended September 30, 2017 Distributions Received Income from Equity Investments Purchase Price Adjustment Distributions received Income from Equity investments Purchase Price Adjustment Bengal $ 5.5 $ 6.2 $ — $ 14.8 $ 16.9 $ — Odyssey 4.4 5.0 — 13.1 13.7 — Mars 21.9 22.0 — 64.2 63.7 — Poseidon 9.6 7.3 — 28.9 20.5 — Proteus 0.6 0.3 — 2.3 1.1 0.3 Endymion 0.5 0.4 — 2.0 1.2 0.1 $ 42.5 $ 41.2 — $ 125.3 $ 117.1 $ 0.4 Three Months Ended September 30, 2016 Nine Months Ended September 30, 2016 Distributions Received Income from Equity Investments Distributions Received Income from Equity Investments Bengal $ 2.7 $ 5.2 $ 16.1 $ 15.9 Mars 11.5 8.6 34.5 31.7 Poseidon 10.5 7.6 31.9 22.6 $ 24.7 $ 21.4 $ 82.5 $ 70.2
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 September 30, 2017 Total Revenues Total Operating Expenses Operating Income Net Income Statements of Income Bengal $ 18.7 $ 6.8 $ 11.9 $ 11.9 Odyssey 11.1 1.0 10.1 10.1 Mars 66.0 19.5 46.5 46.5 Poseidon 30.6 8.2 22.4 20.7 Proteus 7.6 2.9 4.7 4.4 Endymion 8.2 3.3 4.9 4.9 Nine Months Ended September 30, 2017 Total Revenues Total Operating Expenses Operating Income Net Income Statements of Income Bengal $ 54.6 $ 21.1 $ 33.5 $ 33.4 Odyssey 30.8 3.0 27.8 27.8 Mars 197.3 63.7 133.6 133.6 Poseidon 88.0 24.8 63.2 58.7 Proteus 22.8 9.0 13.8 12.9 Endymion 25.3 9.6 15.7 14.9 Three Months Ended September 30, 2016 Total Revenues Total Operating Expenses Operating Income Net Income Statements of Income Bengal $ 17.3 $ 7.2 $ 10.1 $ 10.3 Mars 54.0 23.1 30.9 30.9 Poseidon 31.3 8.2 23.1 22.0 Nine Months Ended September 30, 2016 Total Revenues Total Operating Expenses Operating Income Net Income Statements of Income Bengal $ 52.3 $ 20.7 $ 31.6 $ 31.7 Mars 175.5 62.1 113.4 113.4 Poseidon 90.7 22.5 68.2 64.7

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	9 Months Ended
	Sep. 30, 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 September 30, 2017 December 31, 2016 Land — $ 2.0 $ 2.0 Building and improvements 10 - 40 years 37.0 29.6 Pipeline and equipment (1) 10 - 30 years 888.2 895.7 Other 5 - 25 years 15.5 16.9 942.7 944.2 Accumulated depreciation and amortization (2) (368.1 ) (354.8 ) 574.6 589.4 Construction in progress 34.3 21.2 Property, plant and equipment, net $ 608.9 $ 610.6 (1) As of September 30, 2017 , includes cost of $163.4 million related to assets under operating lease (as lessor), which commenced in May 2017 . As of September 30, 2017 and December 31, 2016, includes cost of $22.8 million related to assets under capital lease (as lessee). (2) As of September 30, 2017 , includes accumulated depreciation of $32.1 million related to assets under operating lease (as lessor), which commenced in May 2017. As of September 30, 2017 and December 31, 2016, includes accumulated depreciation of $2.7 million and $1.6 million , respectively, related to assets under capital lease (as lessee).

Accrued Liabilities - Third P25

Accrued Liabilities - Third Parties (Tables)	9 Months Ended
	Sep. 30, 2017
Payables and Accruals [Abstract]
Schedule of Accrued Liabilities	Accrued liabilities - third parties consist of the following as of the dates indicated: September 30, 2017 December 31, 2016 Transportation, project engineering $ 7.8 $ 4.2 Property taxes 7.2 0.6 Professional fees 0.5 0.3 Other accrued liabilities 1.7 1.8 Accrued liabilities - third parties $ 17.2 $ 6.9

Related Party Debt (Tables)

Related Party Debt (Tables)	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Schedule of Consolidated Related Party Debt Obligations	Consolidated related party debt obligations comprise the following as of the dates indicated: September 30, 2017 December 31, 2016 Five Year Fixed Facility, fixed rate, due March 1, 2022 (1) $ 506.9 $ — Five Year Revolver, variable rate, due October 31, 2019 (2) 495.0 686.9 Zydeco Revolver, variable rate, due August 6, 2019 (3) — — 364-Day Revolver, variable rate, expired March 1, 2017 (4) — — Unamortized debt issuance costs (1.3 ) (0.9 ) Debt payable – related party $ 1,000.6 $ 686.0 (1) As of September 30, 2017 , availability under the $600.0 million Five Year Fixed Facility was $93.1 million . (2) As of September 30, 2017 , availability under the $760.0 million Five Year Revolver was $265.0 million . (3) As of September 30, 2017 , the entire $30.0 million capacity was available under the Zydeco Revolver. (4) The 364 -Day Revolver expired March 1, 2017.

Equity (Tables)

Equity (Tables)	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Schedule of Changes in Number of Units Outstanding	The changes in the number of units outstanding from December 31, 2016 through September 30, 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 ) — — Units issued in connection with ATM program 5,294,925 — — 108,060 5,402,985 Units issued in connection with public offering 5,170,000 — — 105,510 5,275,510 Balance as of September 30, 2017 98,832,233 88,950,136 — 3,832,293 191,614,662
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 $ 13.9 $ 4.7 $ 14.8 $ 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 25.7 25.9 — 10.7 1.3 63.6 0.29100 August 14, 2017 June 30, 2017 26.9 27.0 — 12.9 1.4 68.2 0.30410 November 14, 2017 September 30, 2017 (1) 31.4 28.3 — 16.2 1.5 77.4 0.31800 (1) For more information see Note 12 — Subsequent Events .

Net Income Per Limited Partne28

Net Income Per Limited Partner Unit (Tables)	9 Months Ended
	Sep. 30, 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 Nine Months Ended 2017 2016 2017 2016 Net income $ 74.5 $ 61.8 $ 218.2 $ 204.5 Less: Net income attributable to Parent — 3.0 3.0 11.4 Net income attributable to noncontrolling interests 1.9 2.5 6.3 17.7 Net income attributable to the Partnership 72.6 56.3 208.9 175.4 Less: General Partner's distribution declared 17.7 7.1 44.0 14.7 Limited Partners' distribution declared on common units 59.7 29.0 165.2 79.4 Limited Partners' distribution declared on subordinated units — 17.8 — 50.5 Income (less than) / in excess of distributions $ (4.8 ) $ 2.4 $ (0.3 ) $ 30.8
Schedule of Basic and Diluted Net Income Per Unit	Three Months Ended September 30, 2017 General Partner Limited Partners' Common Units Total (in millions of dollars, except per unit data) Distributions declared $ 17.7 $ 59.7 $ 77.4 Distributions in excess of income (0.1 ) (4.7 ) (4.8 ) Net income attributable to the Partnership $ 17.6 $ 55.0 $ 72.6 Weighted average units outstanding (in millions) (1) : Basic and diluted 179.2 Net income per Limited Partner Unit (in dollars): Basic and diluted $ 0.31 Nine Months Ended September 30, 2017 General Partner Limited Partners' Common Units Total (in millions of dollars, except per unit data) Distributions declared $ 44.0 $ 165.2 $ 209.2 Distributions in excess of income — (0.3 ) (0.3 ) Net income attributable to the Partnership $ 44.0 $ 164.9 $ 208.9 Weighted average units outstanding (in millions) (1) : Basic and diluted 178.0 Net income per Limited Partner Unit (in dollars): Basic and diluted $ 0.93 (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 September 30, 2016 General Partner Limited Partners' Common Units Limited Partners' Subordinated Units Total (in millions of dollars, except per unit data) Distributions declared $ 7.1 $ 29.0 $ 17.8 $ 53.9 Income in excess of distributions 0.1 1.4 0.9 2.4 Net income attributable to the Partnership $ 7.2 $ 30.4 $ 18.7 $ 56.3 Weighted average units outstanding (in millions): Basic and diluted 109.8 67.5 Net income per Limited Partner Unit (in dollars): Basic and diluted $ 0.28 $ 0.28 Nine Months Ended September 30, 2016 General Partner Limited Partners' Common Units Limited Partners' Subordinated Units Total (in millions of dollars, except per unit data) Distributions declared $ 14.7 $ 79.4 $ 50.5 $ 144.6 Income in excess of distributions 0.6 18.0 12.2 30.8 Net income attributable to the Partnership $ 15.3 $ 97.4 $ 62.7 $ 175.4 Weighted average units outstanding (in millions): Basic and diluted 99.2 67.5 Net income per Limited Partner Unit (in dollars): Basic and diluted $ 0.98 $ 0.93

Description of Business and B29

Description of Business and Basis of Presentation (Details)	9 Months Ended
	Sep. 30, 2017segmentsystem	Dec. 31, 2016
Description Of Business And Basis Of Presentation [Line Items]
Number of pipeline systems	9
Number of refined products systems	3
Number of natural gas gathering pipeline systems	1
Number of gas pipeline systems	1
Number of crude tank storage and terminal systems	1
Number of reportable segments | segment	1
Pecten Midstream LLC (“Pecten”)
Description Of Business And Basis Of Presentation [Line Items]
SHLX Ownership	100.00%
Shell's Retained Ownership	0.00%
Sand Dollar Pipeline LLC (“Sand Dollar”)
Description Of Business And Basis Of Presentation [Line Items]
SHLX Ownership	100.00%
Shell's Retained Ownership	0.00%
Zydeco Pipeline Company LLC (“Zydeco”)
Description Of Business And Basis Of Presentation [Line Items]
SHLX Ownership	92.50%
Shell's Retained Ownership	7.50%
Bengal Pipeline Company LLC (“Bengal”)
Description Of Business And Basis Of Presentation [Line Items]
SHLX Ownership	50.00%	50.00%
Shell's Retained Ownership	0.00%
Odyssey Pipeline LLC (“Odyssey”)
Description Of Business And Basis Of Presentation [Line Items]
SHLX Ownership	49.00%	49.00%
Shell's Retained Ownership	22.00%
Mars Oil Pipeline Company LLC (“Mars”)
Description Of Business And Basis Of Presentation [Line Items]
SHLX Ownership	48.60%	48.60%
Shell's Retained Ownership	22.90%
Poseidon Oil Pipeline Company LLC (“Poseidon”)
Description Of Business And Basis Of Presentation [Line Items]
SHLX Ownership	36.00%	36.00%
Shell's Retained Ownership	0.00%
Proteus Oil Pipeline Company, LLC (“Proteus”)
Description Of Business And Basis Of Presentation [Line Items]
SHLX Ownership	10.00%	10.00%
Shell's Retained Ownership	0.00%
Endymion Oil Pipeline Company, LLC (“Endymion”)
Description Of Business And Basis Of Presentation [Line Items]
SHLX Ownership	10.00%	10.00%
Shell's Retained Ownership	0.00%
Colonial Pipeline Company (“Colonial”)
Description Of Business And Basis Of Presentation [Line Items]
SHLX Ownership	6.00%
Shell's Retained Ownership	10.12%
Explorer Pipeline Company (“Explorer”)
Description Of Business And Basis Of Presentation [Line Items]
SHLX Ownership	2.62%
Shell's Retained Ownership	35.97%
Cleopatra Gas Gathering Company, LLC (“Cleopatra”)
Description Of Business And Basis Of Presentation [Line Items]
SHLX Ownership	1.00%
Shell's Retained Ownership	0.00%

Acquisitions and Divestitures

Acquisitions and Divestitures - Additional Information (Details) - USD ($) $ in Millions

Sep. 15, 2017

May 10, 2017

Apr. 28, 2017

Mar. 01, 2017

Sep. 27, 2016

Aug. 09, 2016

Jun. 09, 2016

May 23, 2016

Mar. 29, 2016

May 12, 2015

Nov. 03, 2014

May 31, 2017

Jun. 30, 2017

Sep. 30, 2017

Jun. 30, 2017

Mar. 31, 2016

Sep. 30, 2017

Sep. 30, 2017

Sep. 30, 2016

[2]

Business Acquisition [Line Items]

Historical carrying value of property, plant and equipment acquired

$ 9.9

April 2017 Divestiture

$ 0.8

[1]

$ 0

Proceeds from April 2017 divestiture

[3]

20.2

Net proceeds from public offering

[3]

$ 283.7

Units issued in connection with public offering (in shares)

5,275,510

Contributions from general partner

$ 5.8

[1]

9.8

Aggregate percentage of general partner interest

2.00%

Capital distributions to general partner, cash

$ 429.3

[1]

$ 599.2

Shell Treasury Center West Inc | Five Year Fixed Facility

Business Acquisition [Line Items]

Debt instrument term

5 years

Shell Treasury Center West Inc | Five Year Revolver

Business Acquisition [Line Items]

Debt instrument term

5 years

5 years

5 years

5 years

5 years

General Partner

Business Acquisition [Line Items]

Units issued in connection with public offering (in shares)

105,510

32,143

258,163

105,510

Contributions from general partner

$ 1.1

$ 8.2

$ 2.9

$ 0.1

$ 0.5

Aggregate percentage of general partner interest

2.00%

2.00%

2.00%

2.00%

2.00%

2.00%

2.00%

Shell Pipeline Company L P | Common Units

Business Acquisition [Line Items]

Units issued in connection with public offering (in shares)

0

Shell Pipeline Company L P | General Partner

Business Acquisition [Line Items]

Proceeds from April 2017 divestiture

$ 18.7

Net proceeds from public offering

$ 5.8

Zydeco Pipeline Company LLC (“Zydeco”) | Disposed of by sale

Business Acquisition [Line Items]

April 2017 Divestiture

$ 21

Net assets divested

0.8

Proceeds from April 2017 divestiture

20.2

Zydeco Pipeline Company LLC (“Zydeco”) | Disposed of by sale | Shell Pipeline Company L P

Business Acquisition [Line Items]

April 2017 Divestiture

$ 19.4

Revolving Credit Facility | Shell Treasury Center West Inc | Five Year Revolver

Business Acquisition [Line Items]

Debt instrument term

5 years

5 years

5 years

5 years

5 years

Fixed Facility | Shell Treasury Center West Inc | Five Year Fixed Facility

Business Acquisition [Line Items]

Debt instrument term

5 years

5 years

Delta

Business Acquisition [Line Items]

Interest acquired

100.00%

May 2017 Acquisition

Business Acquisition [Line Items]

Consideration transferred

$ 630

Consideration, cash on hand

50

Transaction costs

0.8

Purchase option and right of refusal, shutdown period (in years)

2 years

Capital distributions to general partner

$ 429.3

Revenue related to the assets acquired

$ 40.1

Net earnings related to the assets acquired

$ 18.9

May 2017 Acquisition | Shell Treasury Center West Inc | Five Year Fixed Facility

Business Acquisition [Line Items]

Debt instrument term

5 years

May 2017 Acquisition | Shell Treasury Center West Inc | Five Year Revolver

Business Acquisition [Line Items]

Debt instrument term

5 years

May 2017 Acquisition | Revolving Credit Facility | Shell Treasury Center West Inc | Five Year Revolver

Business Acquisition [Line Items]

Consideration, funded with borrowings

$ 73.1

Debt instrument term

5 years

5 years

May 2017 Acquisition | Fixed Facility | Shell Treasury Center West Inc | Five Year Fixed Facility

Business Acquisition [Line Items]

Consideration, funded with borrowings

$ 506.9

Debt instrument term

5 years

Na Kika

Business Acquisition [Line Items]

Interest acquired

100.00%

Refinery Gas Pipeline

Business Acquisition [Line Items]

Interest acquired

100.00%

Zydeco Pipeline Company LLC (“Zydeco”)

Business Acquisition [Line Items]

Interest acquired

30.00%

August 2016 Acquisition

Business Acquisition [Line Items]

Interest acquired

2.62%

Consideration transferred

$ 26.2

Consideration, cash on hand

26.3

Transaction costs

$ 0.1

Explorer Pipeline Company

Business Acquisition [Line Items]

Noncontrolling interest, ownership percentage by noncontrolling owners

35.97%

Bengal

Business Acquisition [Line Items]

Interest acquired

1.00%

Colonial Pipeline Company (“Colonial”)

Business Acquisition [Line Items]

Interest acquired

3.00%

May 2016 Acquisition

Business Acquisition [Line Items]

Consideration transferred

$ 700

Consideration, cash on hand

50.4

Transaction costs

0.4

Capital distributions to general partner

606.3

Capital distributions to general partner, cash

599.2

Other non-cash capital distributions to general partner

$ 7.1

May 2016 Acquisition | Shell Treasury Center West Inc | Five Year Revolver

Business Acquisition [Line Items]

Debt instrument term

5 years

May 2016 Acquisition | Common Units

Business Acquisition [Line Items]

Net proceeds from public offering

$ 345.8

Units issued in connection with public offering (in shares)

10,500,000

May 2016 Acquisition | General Partner

Business Acquisition [Line Items]

Units issued in connection with public offering (in shares)

214,285

Contributions from general partner

$ 7.1

Aggregate percentage of general partner interest

2.00%

May 2016 Acquisition | Revolving Credit Facility | Shell Treasury Center West Inc | Five Year Revolver

Business Acquisition [Line Items]

Consideration, funded with borrowings

$ 296.7

[1]

The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta,Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.

[2]

Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.

[3]

Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.

Acquisitions and Divestitures31

Acquisitions and Divestitures - Book Value of Assets Acquired (Details) - USD ($) $ in Millions	May 23, 2016	May 10, 2017
Delta
Business Acquisition [Line Items]
Book value of assets acquired		$ 40.1
Interest acquired		100.00%
Na Kika
Business Acquisition [Line Items]
Book value of assets acquired		$ 26
Interest acquired		100.00%
Refinery Gas Pipeline
Business Acquisition [Line Items]
Book value of assets acquired		$ 134.6
Interest acquired		100.00%
May 2017 Acquisition
Business Acquisition [Line Items]
Book value of assets acquired		$ 200.7
May 2016 Acquisition
Business Acquisition [Line Items]
Book value of assets acquired	$ 93.7
Cost investment	5.2
Equity method investments	1.5
Partner's capital	$ 87
Colonial Pipeline Company (“Colonial”)
Business Acquisition [Line Items]
Interest acquired	3.00%
Bengal
Business Acquisition [Line Items]
Interest acquired	1.00%
Zydeco Pipeline Company LLC (“Zydeco”)
Business Acquisition [Line Items]
Interest acquired	30.00%

Acquisitions and Divestitures32

Acquisitions and Divestitures - Balance Sheet (Details) - USD ($) $ in Millions		Sep. 30, 2017		Dec. 31, 2016		Sep. 30, 2016		Dec. 31, 2015
Current assets
Cash and cash equivalents		$ 171.9	[1]	$ 121.9	[1],[2]	$ 160.8	[3]	$ 93	[3]
Accounts receivable – third parties, net		12.9		20.8	[2]
Accounts receivable – related parties		16.2		12.1	[2]
Allowance oil		10.7		11.7	[2]
Prepaid expenses		1.2		6.5	[2]
Total current assets		212.9		173	[2]
Equity method investments		253.8		262.4	[2]
Property, plant and equipment, net		608.9		610.6	[2]
Cost investments		39.8		39.8	[2]
Other assets		1.3		0.6	[2]
Total assets		1,116.7		1,086.4	[2]
Current liabilities
Accounts payable – third parties		2.5		4.1	[2]
Accounts payable – related parties		10.5		5.4	[2]
Deferred revenue – third parties		6.5		6	[2]
Deferred revenue – related parties		20.8		7.9	[2]
Accrued liabilities – third parties		17.2		6.9	[2]
Accrued liabilities – related parties		5.9		5.1	[2]
Total current liabilities		63.4		35.4	[2]
Noncurrent liabilities
Debt payable – related party		1,000.6		686	[2]
Lease liability – related party		24.4		24.9	[2]
Asset retirement obligations		1.4		1.4	[2]
Other unearned income		2.7		2.1	[2]
Total noncurrent liabilities		1,029.1		714.4	[2]
Total liabilities		1,092.5		749.8	[2]
Commitments and Contingencies (Note 11)					[2]
EQUITY
Total partners' capital		3.4		98.3	[2]
Noncontrolling interest		20.8		21.6	[2]
Net parent investment		0		216.7	[2]
Total equity	[4]	24.2		336.6	[2]
Total liabilities and equity		1,116.7		1,086.4	[2]
Shell Pipeline Company L P
EQUITY
General partner unitholders		(2,256.8)		(1,873.7)	[2]
Common Units | General Public
EQUITY
Limited partner unitholders		2,770.4		2,485.7	[2]
Common Units | Shell Pipeline Company L P
EQUITY
Limited partner unitholders		(510.2)		(124.1)	[2]
Subordinated Units | Shell Pipeline Company L P
EQUITY
Limited partner unitholders		0		(389.6)	[2]
Total equity		$ 0		(389.6)
Previously Reported
Current assets
Cash and cash equivalents				121.9		160.8		93
Accounts receivable – third parties, net				18.4
Accounts receivable – related parties				10.1
Allowance oil				9
Prepaid expenses				6
Total current assets				165.4
Equity method investments				262.4
Property, plant and equipment, net				398
Cost investments				39.8
Other assets				0
Total assets				865.6
Current liabilities
Accounts payable – third parties				1.5
Accounts payable – related parties				5.2
Deferred revenue – third parties				6
Deferred revenue – related parties				7.9
Accrued liabilities – third parties				5.6
Accrued liabilities – related parties				5.1
Total current liabilities				31.3
Noncurrent liabilities
Debt payable – related party				686
Lease liability – related party				24.9
Asset retirement obligations				1.4
Other unearned income				2.1
Total noncurrent liabilities				714.4
Total liabilities				745.7
Commitments and Contingencies (Note 11)
EQUITY
Total partners' capital				98.3
Noncontrolling interest				21.6
Net parent investment				0
Total equity				119.9
Total liabilities and equity				865.6
Previously Reported | Shell Pipeline Company L P
EQUITY
General partner unitholders				(1,873.7)
Previously Reported | Common Units | General Public
EQUITY
Limited partner unitholders				2,485.7
Previously Reported | Common Units | Shell Pipeline Company L P
EQUITY
Limited partner unitholders				(124.1)
Previously Reported | Subordinated Units | Shell Pipeline Company L P
EQUITY
Limited partner unitholders				(389.6)
Adjustment
Current assets
Cash and cash equivalents				0		$ 0		$ 0
Accounts receivable – third parties, net				2.4
Accounts receivable – related parties				2
Allowance oil				2.7
Prepaid expenses				0.5
Total current assets				7.6
Equity method investments				0
Property, plant and equipment, net				212.6
Cost investments				0
Other assets				0.6
Total assets				220.8
Current liabilities
Accounts payable – third parties				2.6
Accounts payable – related parties				0.2
Deferred revenue – third parties				0
Deferred revenue – related parties				0
Accrued liabilities – third parties				1.3
Accrued liabilities – related parties				0
Total current liabilities				4.1
Noncurrent liabilities
Debt payable – related party				0
Lease liability – related party				0
Asset retirement obligations				0
Other unearned income				0
Total noncurrent liabilities				0
Total liabilities				4.1
Commitments and Contingencies (Note 11)
EQUITY
Total partners' capital				0
Noncontrolling interest				0
Net parent investment				216.7
Total equity				216.7
Total liabilities and equity				220.8
Adjustment | Shell Pipeline Company L P
EQUITY
General partner unitholders				0
Adjustment | Common Units | General Public
EQUITY
Limited partner unitholders				0
Adjustment | Common Units | Shell Pipeline Company L P
EQUITY
Limited partner unitholders				0
Adjustment | Subordinated Units | Shell Pipeline Company L P
EQUITY
Limited partner unitholders				$ 0
[1]	The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta,Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.
[2]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.
[3]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.
[4]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.

Acquisitions and Divestitures33

Acquisitions and Divestitures - Statement of Income (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016		Sep. 30, 2017	[2]	Sep. 30, 2016
Revenue
Third parties		$ 53.8				$ 174.9
Related parties		28.1				86
Total revenue	$ 94.4	81.9	[1]	$ 265.6		260.9	[1]
Costs and expenses
Operations and maintenance – third parties	25.8	14.1	[1]	64.3		41.7	[1]
Operations and maintenance – related parties	8.4	7.5	[1]	26.6		22.6	[1]
General and administrative – third parties	1	2.2	[1]	5.6		6.4	[1]
General and administrative – related parties	8.6	7.4	[1]	25.2		22.3	[1]
Depreciation, amortization and accretion	8.9	9.1	[1]	28	[3]	27.1	[1],[4]
Property and other taxes	3.6	2.6	[1]	11.2		10.3	[1]
Total costs and expenses	56.3	42.9	[1]	160.9		130.4	[1]
Operating income	38.1	39	[1]	104.7		130.5	[1]
Income from equity investments	41.2	21.4	[1]	117.1		70.2	[1]
Dividend income from cost investments	4.8	4.2	[1]	18.3		11.6	[1]
Investment, dividend and other income	46.1	25.6	[1]	135.5		81.8	[1]
Interest expense, net	9.7	2.8	[1]	22		7.8	[1]
Income before income taxes	74.5	61.8	[1]	218.2		204.5	[1]
Income tax expense	0	0	[1]	0		0	[1]
Net income	74.5	61.8	[1]	218.2	[3],[5]	204.5	[1],[4]
Less: Net income attributable to Parent	0	3	[1]	3		11.4	[1]
Less: Net income attributable to noncontrolling interests	1.9	2.5	[1]	6.3		17.7	[1]
Net income attributable to the Partnership	$ 72.6	56.3	[1]	$ 208.9		175.4	[1]
Previously Reported
Revenue
Third parties		46.1				149.8
Related parties		21.8				65.9
Total revenue		67.9				215.7
Costs and expenses
Operations and maintenance – third parties		11.4				33.1
Operations and maintenance – related parties		5.3				15.9
General and administrative – third parties		2.2				6.2
General and administrative – related parties		5.7				17.3
Depreciation, amortization and accretion		6				17.7
Property and other taxes		1.3				6.4
Total costs and expenses		31.9				96.6
Operating income		36				119.1
Income from equity investments		21.4				70.2
Dividend income from cost investments		4.2				11.6
Investment, dividend and other income		25.6				81.8
Interest expense, net		2.8				7.8
Income before income taxes		58.8				193.1
Income tax expense		0				0
Net income		58.8				193.1
Less: Net income attributable to Parent		0				0
Less: Net income attributable to noncontrolling interests		2.5				17.7
Net income attributable to the Partnership		56.3				175.4
Adjustment
Revenue
Third parties		7.7				25.1
Related parties		6.3				20.1
Total revenue		14				45.2
Costs and expenses
Operations and maintenance – third parties		2.7				8.6
Operations and maintenance – related parties		2.2				6.7
General and administrative – third parties		0				0.2
General and administrative – related parties		1.7				5
Depreciation, amortization and accretion		3.1				9.4
Property and other taxes		1.3				3.9
Total costs and expenses		11				33.8
Operating income		3				11.4
Income from equity investments		0				0
Dividend income from cost investments		0				0
Investment, dividend and other income		0				0
Interest expense, net		0				0
Income before income taxes		3				11.4
Income tax expense		0				0
Net income		3				11.4
Less: Net income attributable to Parent		3				11.4
Less: Net income attributable to noncontrolling interests		0				0
Net income attributable to the Partnership		$ 0				$ 0
[1]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.
[2]	The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.
[3]	The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta,Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.
[4]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.
[5]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.

Acquisitions and Divestitures34

Acquisitions and Divestitures - Statement of Cash Flows (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2017		Sep. 30, 2016		Sep. 30, 2017		Sep. 30, 2016
Cash flows from operating activities
Net income	$ 74.5		$ 61.8	[1]	$ 218.2	[2],[3],[4]	$ 204.5	[1],[5]
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation, amortization and accretion	8.9		9.1	[1]	28	[3],[4]	27.1	[1],[5]
Non-cash interest expense					0.3	[4]	0.2	[5]
Undistributed equity earnings					(4.1)	[4]	2.7	[5]
Changes in operating assets and liabilities
Accounts receivable					(0.9)	[4]	7.3	[5]
Allowance oil					(1.7)	[4]	(3.8)	[5]
Prepaid expenses					4.4	[4]	5	[5]
Accounts payable					3.6	[4]	(2.3)	[5]
Deferred revenue					14	[4]	(0.4)	[5]
Accrued liabilities					13.9	[4]	8.2	[5]
Net cash provided by operating activities					276	[4]	248.5	[5]
Cash flows from investing activities
Capital expenditures					(35.5)	[4]	(28.8)	[5]
Acquisitions					(200.7)	[4]	(120)	[5]
Return of investment					12.3	[4]	9.6	[5]
Net cash used in investing activities					(222.7)	[4]	(139.2)	[5]
Cash flows from financing activities
Net proceeds from public offerings					277.9	[4]	818.1	[5]
Borrowing under credit facility					580	[4]	296.7	[5]
Contributions from general partner					5.8	[4]	9.8	[5]
Repayment of credit facilities					(265)	[4]	(410)	[5]
Capital distributions to general partner					(429.3)	[4]	(599.2)	[5]
Distributions to noncontrolling interest					(8.6)	[4]	(17.1)	[5]
Distributions to unitholders and general partner					(190.4)	[4]	(126)	[5]
Net distributions to Parent					(6.3)	[4]	(16.9)	[5]
Other contributions from Parent					13.6	[4]	3.1	[5]
Net cash used in financing activities					(3.3)	[4]	(41.5)	[5]
Net increase in cash and cash equivalents					50	[4]	67.8	[5]
Cash and cash equivalents at beginning of the period					121.9	[4],[6]	93	[5]
Cash and cash equivalents at end of the period	$ 171.9	[4]	160.8	[5]	171.9	[4]	160.8	[5]
Change in accrued capital expenditures					1.5	[4]	(5.3)	[5]
Other non-cash contributions from Parent					1.5	[4]	0.3	[5]
Other non-cash capital distributions to general partner					0	[4]	(7.1)	[5]
Other non-cash contribution from general partner					0	[4]	7.1	[5]
Other non-cash credit facilities issuance costs					0	[4]	(0.6)	[5]
Previously Reported
Cash flows from operating activities
Net income			58.8				193.1
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation, amortization and accretion			6				17.7
Non-cash interest expense							0.2
Undistributed equity earnings							2.7
Changes in operating assets and liabilities
Accounts receivable							6.6
Allowance oil							(3.6)
Prepaid expenses							4.3
Accounts payable							(1.6)
Deferred revenue							(0.4)
Accrued liabilities							5.1
Net cash provided by operating activities							224.1
Cash flows from investing activities
Capital expenditures							(21.3)
Acquisitions							(120)
Return of investment							9.6
Net cash used in investing activities							(131.7)
Cash flows from financing activities
Net proceeds from public offerings							818.1
Borrowing under credit facility							296.7
Contributions from general partner							9.8
Repayment of credit facilities							(410)
Capital distributions to general partner							(599.2)
Distributions to noncontrolling interest							(17.1)
Distributions to unitholders and general partner							(126)
Net distributions to Parent							0
Other contributions from Parent							3.1
Net cash used in financing activities							(24.6)
Net increase in cash and cash equivalents							67.8
Cash and cash equivalents at beginning of the period					121.9		93
Cash and cash equivalents at end of the period			160.8				160.8
Change in accrued capital expenditures							(1.1)
Other non-cash contributions from Parent							0.3
Other non-cash capital distributions to general partner							(7.1)
Other non-cash contribution from general partner							7.1
Other non-cash credit facilities issuance costs							(0.6)
Adjustment
Cash flows from operating activities
Net income			3				11.4
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation, amortization and accretion			3.1				9.4
Non-cash interest expense							0
Undistributed equity earnings							0
Changes in operating assets and liabilities
Accounts receivable							0.7
Allowance oil							(0.2)
Prepaid expenses							0.7
Accounts payable							(0.7)
Deferred revenue							0
Accrued liabilities							3.1
Net cash provided by operating activities							24.4
Cash flows from investing activities
Capital expenditures							(7.5)
Acquisitions							0
Return of investment							0
Net cash used in investing activities							(7.5)
Cash flows from financing activities
Net proceeds from public offerings							0
Borrowing under credit facility							0
Contributions from general partner							0
Repayment of credit facilities							0
Capital distributions to general partner							0
Distributions to noncontrolling interest							0
Distributions to unitholders and general partner							0
Net distributions to Parent							(16.9)
Other contributions from Parent							0
Net cash used in financing activities							(16.9)
Net increase in cash and cash equivalents							0
Cash and cash equivalents at beginning of the period					$ 0		0
Cash and cash equivalents at end of the period			$ 0				0
Change in accrued capital expenditures							(4.2)
Other non-cash contributions from Parent							0
Other non-cash capital distributions to general partner							0
Other non-cash contribution from general partner							0
Other non-cash credit facilities issuance costs							$ 0
[1]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.
[2]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.
[3]	The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.
[4]	The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta,Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.
[5]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.
[6]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.

Related Party Transactions - Ad

Related Party Transactions - Additional Information (Details)

Sep. 15, 2017USD ($)

Sep. 27, 2016

Mar. 29, 2016USD ($)

Nov. 11, 2015

Jun. 29, 2015

May 12, 2015

Nov. 03, 2014USD ($)

Sep. 30, 2017USD ($)credit_facility

Sep. 30, 2016USD ($)

Mar. 31, 2016

Sep. 30, 2017USD ($)credit_facilityterm

Sep. 30, 2016USD ($)

Dec. 31, 2016

May 23, 2016

May 31, 2015

Related Party Transaction [Line Items]

Repayments of Lines of Credit

$ 265,000,000

[1]

$ 410,000,000

[2]

Reimbursement Of Cost And Expenses Incurred

$ 3,100,000

13,600,000

Aggregate liability of SPLC

10,700,000

10,700,000

Statute of limitations expirations, number of days

60 days

Revenue from related parties

$ 28,100,000

86,000,000

Gain (loss) from sale of excess allowance oil

100,000

300,000

800,000

800,000

Transportation Services

Related Party Transaction [Line Items]

Revenue from related parties

28,600,000

25,800,000

77,900,000

79,500,000

Storage Services

Related Party Transaction [Line Items]

Revenue from related parties

1,200,000

2,300,000

4,600,000

6,500,000

Transportation Services Operating Leases

Related Party Transaction [Line Items]

Revenue from related parties

$ 11,700,000

0

$ 19,400,000

0

Initial term

10 years

Number of additional terms | term

2

Additional term

5 years

Shell Treasury Center West Inc

Related Party Transaction [Line Items]

Number of revolving credit facilities | credit_facility

3

3

Zydeco, Mars, Bengal, Poseidon and Colonial

Related Party Transaction [Line Items]

Total distributions to general partners

$ 71,400,000

63,900,000

$ 249,100,000

174,800,000

SPLC

Related Party Transaction [Line Items]

General and administrative - related parties

3,400,000

2,300,000

8,400,000

7,800,000

General insurance expense

$ 2,100,000

1,200,000

$ 5,100,000

4,200,000

Five Year Revolver | Shell Treasury Center West Inc

Related Party Transaction [Line Items]

Debt instrument term

5 years

5 years

5 years

5 years

5 years

Five Year Fixed Facility | Shell Treasury Center West Inc

Related Party Transaction [Line Items]

Debt instrument term

5 years

364 Day Revolver | Shell Treasury Center West Inc

Related Party Transaction [Line Items]

Repayments of Lines of Credit

$ 137,400,000

Debt instrument term

364 days

364 days

364 days

SPLC | Zydeco Pipeline Company LLC (“Zydeco”)

Related Party Transaction [Line Items]

Noncontrolling Interest

57.00%

7.50%

7.50%

7.50%

7.50%

37.50%

Maximum

Related Party Transaction [Line Items]

Aggregate liability of SPLC

$ 15,000,000

Shell Auger and Lockport Operations

Related Party Transaction [Line Items]

Reimbursement Of Cost And Expenses Incurred

1,000,000

1,200,000

Shell Pipeline Company L P

Related Party Transaction [Line Items]

Payment of general and administrative fee

$ 8,500,000

Zydeco Pipeline Company LLC (“Zydeco”)

Related Party Transaction [Line Items]

Reimbursement Of Cost And Expenses Incurred

$ 2,200,000

100,000

$ 12,100,000

400,000

Total distributions to general partners

$ 24,100,000

$ 35,100,000

$ 105,500,000

$ 80,700,000

Revolving Credit Facility [Member] | Five Year Revolver | Shell Treasury Center West Inc

Related Party Transaction [Line Items]

Repayments of Lines of Credit

$ 265,000,000

$ 272,600,000

Debt instrument term

5 years

5 years

5 years

5 years

5 years

Revolving Credit Facility [Member] | 364 Day Revolver | Shell Treasury Center West Inc

Related Party Transaction [Line Items]

Debt instrument term

364 days

364 days

364 days

[1]

The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta,Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.

[2]

Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.

Related Party Transactions - Sc

Related Party Transactions - Schedule of Other Related Party Balances (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Related Party Transaction [Line Items]
Accounts receivable	$ 16.2	$ 12.1	[1]
Prepaid expenses	0.6	3.2
Other assets	0.7	0
Accounts payable	10.5	5.4	[1]
Deferred revenue	20.8	7.9	[1]
Accrued liabilities	5.9	5.1	[1]
Debt payable	1,000.6	686	[1]
Lease liability	0	24.9
Accrued interest, related parties	5.5	2.6
Other accrued liabilities, related parties	0.4	0.9
Fuel accrual, related parties		1.6
Unamortized debt issuance costs	1.3	0.9
Affiliated Entity
Related Party Transaction [Line Items]
Unamortized debt issuance costs	$ 1.3	$ 0.9
[1]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.

Related Party Transactions - Fu

Related Party Transactions - Future Minimum Payments Receivable (Details) $ in Millions	Sep. 30, 2017USD ($)
Related Party Transactions [Abstract]
Total	$ 443.6
Less than 1 year	46.3
Years 2 to 3	92.6
Years 4 to 5	92.6
More than 5 years	$ 212.1

Related Party Transactions - 38

Related Party Transactions - Schedule of Condensed Combined Statement of Operations (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016		Sep. 30, 2017		Sep. 30, 2016
Related Party Transaction [Line Items]
Operations and maintenance – related parties	$ 8.4	$ 7.5	[1]	$ 26.6	[2]	$ 22.6	[1]
General and administrative – related parties	8.6	7.4	[1]	25.2	[2]	22.3	[1]
Management Agreement
Related Party Transaction [Line Items]
Payment for general administrative services	2.1	1.9		6.1		5.8
Omnibus Agreement
Related Party Transaction [Line Items]
Payment for general administrative services	$ 2.2	$ 2.2		$ 6.4		$ 6.4
[1]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.
[2]	The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.

Related Party Transactions - Pe

Related Party Transactions - Pension and Retirement Savings Plans (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Related Party Transactions [Abstract]
Health and life insurance costs	$ 1.2	$ 0.9	$ 2.9	$ 2.6
Defined contribution benefit plan costs	$ 0.5	$ 0.4	$ 1.1	$ 1.1

Related Party Transactions - Re

Related Party Transactions - Reimbursements from Our General Partner (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Related Party Transaction [Line Items]
Reimbursement of Zydeco directional drill	$ 3.1		$ 13.6
Refinery Gas Pipeline
Related Party Transaction [Line Items]
Reimbursement of Zydeco directional drill	0.9		1.5
Zydeco Pipeline Company LLC (“Zydeco”)
Related Party Transaction [Line Items]
Reimbursement of Zydeco directional drill	$ 2.2	$ 0.1	$ 12.1	$ 0.4
Shell Auger and Lockport Operations
Related Party Transaction [Line Items]
Reimbursement of Zydeco directional drill		$ 1		$ 1.2

Equity Method Investments - Sch

Equity Method Investments - Schedule of Equity Investments in Affiliates (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Investment Amount	$ 253.8	$ 262.4	[1]
Bengal
Schedule of Equity Method Investments [Line Items]
Ownership	50.00%	50.00%
Investment Amount	$ 78.2	$ 76.1
Odyssey
Schedule of Equity Method Investments [Line Items]
Ownership	49.00%	49.00%
Investment Amount	$ 3.6	$ 3
Mars
Schedule of Equity Method Investments [Line Items]
Ownership	48.60%	48.60%
Investment Amount	$ 129.7	$ 130.2
Poseidon
Schedule of Equity Method Investments [Line Items]
Ownership	36.00%	36.00%
Investment Amount	$ 4.8	$ 13.2
Proteus
Schedule of Equity Method Investments [Line Items]
Ownership	10.00%	10.00%
Investment Amount	$ 17.6	$ 19.1
Endymion
Schedule of Equity Method Investments [Line Items]
Ownership	10.00%	10.00%
Investment Amount	$ 19.9	$ 20.8
[1]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.

Equity Method Investments - Add

Equity Method Investments - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Equity Method Investments and Joint Ventures [Abstract]
Unamortized basis differences included in equity investments	$ 28.4		$ 28.4		$ 30.9
Amortization expense (income)	$ 0.7	$ 0.3	$ 2.1	$ 1.1

Equity Method Investments - S43

Equity Method Investments - Schedule of Equity Investments in Affiliates Balance Affected (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016		Sep. 30, 2017		Sep. 30, 2016
Schedule of Equity Method Investments [Line Items]
Distributions Received	$ 42.5	$ 24.7		$ 125.3		$ 82.5
Income from equity investments	41.2	21.4	[1]	117.1	[2]	70.2	[1]
Purchase price adjustment	0			0.4	[3]	0	[4]
Bengal
Schedule of Equity Method Investments [Line Items]
Distributions Received	5.5	2.7		14.8		16.1
Income from equity investments	6.2	5.2		16.9		15.9
Purchase price adjustment	0			0
Odyssey
Schedule of Equity Method Investments [Line Items]
Distributions Received	4.4			13.1
Income from equity investments	5			13.7
Purchase price adjustment	0			0
Mars
Schedule of Equity Method Investments [Line Items]
Distributions Received	21.9	11.5		64.2		34.5
Income from equity investments	22	8.6		63.7		31.7
Purchase price adjustment	0			0
Poseidon
Schedule of Equity Method Investments [Line Items]
Distributions Received	9.6	10.5		28.9		31.9
Income from equity investments	7.3	$ 7.6		20.5		$ 22.6
Purchase price adjustment	0			0
Proteus
Schedule of Equity Method Investments [Line Items]
Distributions Received	0.6			2.3
Income from equity investments	0.3			1.1
Purchase price adjustment	0			0.3
Endymion
Schedule of Equity Method Investments [Line Items]
Distributions Received	0.5			2
Income from equity investments	0.4			1.2
Purchase price adjustment	$ 0			$ 0.1
[1]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.
[2]	The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.
[3]	The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta,Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.
[4]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.

Equity Method Investments - Sum

Equity Method Investments - Summary of Income Statement Data for Equity Method Investments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Bengal
Schedule of Equity Method Investments [Line Items]
Total Revenues	$ 18.7	$ 17.3	$ 54.6	$ 52.3
Total Operating Expenses	6.8	7.2	21.1	20.7
Operating Income	11.9	10.1	33.5	31.6
Net Income	11.9	10.3	33.4	31.7
Odyssey
Schedule of Equity Method Investments [Line Items]
Total Revenues	11.1		30.8
Total Operating Expenses	1		3
Operating Income	10.1		27.8
Net Income	10.1		27.8
Mars
Schedule of Equity Method Investments [Line Items]
Total Revenues	66	54	197.3	175.5
Total Operating Expenses	19.5	23.1	63.7	62.1
Operating Income	46.5	30.9	133.6	113.4
Net Income	46.5	30.9	133.6	113.4
Poseidon
Schedule of Equity Method Investments [Line Items]
Total Revenues	30.6	31.3	88	90.7
Total Operating Expenses	8.2	8.2	24.8	22.5
Operating Income	22.4	23.1	63.2	68.2
Net Income	20.7	$ 22	58.7	$ 64.7
Proteus
Schedule of Equity Method Investments [Line Items]
Total Revenues	7.6		22.8
Total Operating Expenses	2.9		9
Operating Income	4.7		13.8
Net Income	4.4		12.9
Endymion
Schedule of Equity Method Investments [Line Items]
Total Revenues	8.2		25.3
Total Operating Expenses	3.3		9.6
Operating Income	4.9		15.7
Net Income	$ 4.9		$ 14.9

Property, Plant and Equipment -

Property, Plant and Equipment - Components of Property, Plant and Equipment (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Property Plant And Equipment [Line Items]
Land	$ 2	$ 2
Building and improvements	37	29.6
Pipeline and equipment	888.2	895.7
Other	15.5	16.9
Property, plant and equipment, gross	942.7	944.2
Accumulated depreciation and amortization	(368.1)	(354.8)
Property plant and equipment excluding construction in progress	574.6	589.4
Construction in progress	34.3	21.2
Property, plant and equipment, net	608.9	610.6	[1]
Operating leased assets, cost	163.4
Costs related to assets under capital lease	22.8	22.8
Accumulated depreciation on assets under operating lease	32.1
Accumulated depreciation on assets under capital lease	$ 2.7	$ 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
[1]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.

Property, Plant and Equipment46

Property, Plant and Equipment - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016		Sep. 30, 2017		Sep. 30, 2016
Property, Plant and Equipment [Abstract]
Depreciation and amortization expense	$ 8.9	$ 9.1	[1]	$ 28	[2],[3]	$ 27.1	[1],[4]
[1]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.
[2]	The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.
[3]	The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta,Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.
[4]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.

Accrued Liabilities - Third P47

Accrued Liabilities - Third Parties - Schedule of Accrued Liabilities (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Transportation, project engineering	$ 7.8	$ 4.2
Property taxes	7.2	0.6
Professional fees	0.5	0.3
Other accrued liabilities	1.7	1.8
Accrued liabilities - third parties	$ 17.2	$ 6.9	[1]
[1]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.

Related Party Debt - Schedule o

Related Party Debt - Schedule of Consolidated Related Party Debt Obligations (Details) - USD ($)

Sep. 15, 2017

May 10, 2017

Mar. 01, 2017

Sep. 27, 2016

May 23, 2016

Mar. 29, 2016

Nov. 11, 2015

Jun. 29, 2015

May 12, 2015

Nov. 03, 2014

Sep. 30, 2017

Mar. 31, 2016

Sep. 30, 2017

Dec. 31, 2016

Line Of Credit Facility [Line Items]

Outstanding borrowing

$ 1,000,600,000

$ 1,000,600,000

$ 686,000,000

Unamortized debt issuance costs

$ (1,300,000)

$ (1,300,000)

(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]

Debt instrument term

5 years

5 years

5 years

5 years

5 years

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

364 days

364 days

Fixed Facility | Five Year Fixed Facility, fixed rate, due March 1, 2022

Line Of Credit Facility [Line Items]

Outstanding borrowing

$ 506,900,000

$ 506,900,000

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

$ 600,000,000

Debt instrument term

5 years

5 years

Remaining borrowing capacity

93,100,000

$ 93,100,000

Revolving Credit Facility | Zydeco Pipeline Company LLC (“Zydeco”)

Line Of Credit Facility [Line Items]

Outstanding borrowing

0

0

0

Revolving Credit Facility | Zydeco Pipeline Company LLC (“Zydeco”) | Shell Treasury Center West Inc

Line Of Credit Facility [Line Items]

Line of credit facility maximum borrowing capacity

30,000,000

30,000,000

Revolving Credit Facility | Five Year Revolver, variable rate, due October 31, 2019

Line Of Credit Facility [Line Items]

Outstanding borrowing

495,000,000

495,000,000

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

$ 300,000,000

760,000,000

$ 760,000,000

Debt instrument term

5 years

5 years

5 years

5 years

5 years

Remaining borrowing capacity

265,000,000

$ 265,000,000

Revolving Credit Facility | 364-Day Revolver, variable rate, due March 1, 2017

Line Of Credit Facility [Line Items]

Outstanding borrowing

$ 0

$ 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]

Line of credit facility maximum borrowing capacity

$ 180,000,000

Debt instrument term

364 days

364 days

364 days

May 2017 Acquisition | 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

May 2017 Acquisition | Five Year Revolver, variable rate, due October 31, 2019 | Shell Treasury Center West Inc

Line Of Credit Facility [Line Items]

Debt instrument term

5 years

May 2017 Acquisition | Fixed Facility | 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

May 2017 Acquisition | Revolving Credit Facility | Five Year Revolver, variable rate, due October 31, 2019 | Shell Treasury Center West Inc

Line Of Credit Facility [Line Items]

Debt instrument term

5 years

5 years

Related Party Debt - Additional

Related Party Debt - Additional Information (Details) - USD ($)

Sep. 15, 2017

May 10, 2017

Mar. 07, 2017

Mar. 01, 2017

Sep. 27, 2016

May 23, 2016

Mar. 29, 2016

Nov. 11, 2015

Jun. 29, 2015

May 12, 2015

Nov. 03, 2014

Aug. 06, 2014

Sep. 30, 2017

Sep. 30, 2016

Mar. 31, 2016

Sep. 30, 2017

Sep. 30, 2016

Line Of Credit Facility [Line Items]

Interest and fee expenses

$ 9,100,000

$ 2,000,000

$ 19,800,000

$ 5,000,000

Repayments of debt

265,000,000

[1]

$ 410,000,000

[2]

Level 2

Line Of Credit Facility [Line Items]

Long-term debt, carrying value

1,001,900,000

1,001,900,000

Long-term debt, fair value

$ 1,017,700,000

$ 1,017,700,000

Revolving Credit Facility | Zydeco Pipeline Company LLC (“Zydeco”)

Line Of Credit Facility [Line Items]

Weighted average interest rate

2.80%

Revolving Credit Facility | STCW | Zydeco Pipeline Company LLC (“Zydeco”)

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 Revolver, variable rate, due October 31, 2019

Line Of Credit Facility [Line Items]

Debt instrument term

5 years

5 years

5 years

5 years

5 years

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 | 364-Day Revolver, variable rate, due March 1, 2017

Line Of Credit Facility [Line Items]

Debt instrument term

364 days

364 days

364 days

Repayments of debt

$ 137,400,000

Shell Treasury Center West Inc | Revolving Credit Facility | Zydeco Pipeline Company LLC (“Zydeco”)

Line Of Credit Facility [Line Items]

Line of credit facility maximum borrowing capacity

$ 30,000,000

$ 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

5 years

5 years

5 years

5 years

Repayments of debt

$ 265,000,000

$ 272,600,000

Line of credit facility maximum borrowing capacity

$ 300,000,000

760,000,000

$ 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

364 days

364 days

Line of credit facility maximum borrowing capacity

$ 180,000,000

Shell Treasury Center West Inc | Revolving Credit Facility | 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 | Revolving Credit Facility | Amended And Restated Revolver

Line Of Credit Facility [Line Items]

Line of credit facility maximum borrowing capacity

$ 760,000,000

$ 400,000,000

Issuance fee paid

$ 600,000

Weighted average interest rate

2.40%

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

5 years

Line of credit facility maximum borrowing capacity

$ 600,000,000

$ 600,000,000

Issuance fee paid

$ 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

May 2017 Acquisition

Line Of Credit Facility [Line Items]

Consideration, cash on hand

$ 50,000,000

May 2017 Acquisition | Shell Treasury Center West Inc | Five Year Revolver, variable rate, due October 31, 2019

Line Of Credit Facility [Line Items]

Debt instrument term

5 years

May 2017 Acquisition | 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

May 2017 Acquisition | 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

5 years

Consideration, funded with borrowings

$ 73,100,000

May 2017 Acquisition | 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

Consideration, funded with borrowings

$ 506,900,000

May 2016 Acquisition

Line Of Credit Facility [Line Items]

Consideration, cash on hand

$ 50,400,000

May 2016 Acquisition | Shell Treasury Center West Inc | Five Year Revolver, variable rate, due October 31, 2019

Line Of Credit Facility [Line Items]

Debt instrument term

5 years

May 2016 Acquisition | Shell Treasury Center West Inc | Revolving Credit Facility | Five Year Revolver, variable rate, due October 31, 2019

Line Of Credit Facility [Line Items]

Consideration, funded with borrowings

$ 296,700,000

[1]

The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta,Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.

[2]

Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.

Equity - At-the-Market Program

Equity - At-the-Market Program (Details) - USD ($)	Sep. 15, 2017	Jun. 09, 2016	Mar. 29, 2016	Mar. 02, 2016	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2016	Sep. 30, 2017		Sep. 30, 2016	[2]
Class of Stock [Line Items]
Issuance of common units, maximum proceeds				$ 300,000,000
Units issued under the ATM Program (in shares)								5,402,985
Consideration for units issued to our general partner								$ 5,800,000	[1]	$ 9,800,000
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		5 years		5 years		5 years	5 years
Shell Treasury Center West Inc | 364 Day Revolver
Class of Stock [Line Items]
Debt instrument term			364 days				364 days	364 days
General Partner
Class of Stock [Line Items]
Units issued under the ATM Program (in shares)					106,122	1,938	15,307	108,060
Consideration for units issued to our general partner		$ 1,100,000	$ 8,200,000		$ 2,900,000	$ 100,000	$ 500,000
Aggregate percentage of general partner interest	2.00%	2.00%	2.00%		2.00%	2.00%	2.00%	2.00%
General Public | Common Units
Class of Stock [Line Items]
Units issued under the ATM Program (in shares)					5,200,000	94,925	750,000	5,294,925
Net proceeds from the ATM Program					$ 139,800,000	$ 2,900,000	$ 25,400,000
Gross proceeds from the ATM Program					$ 140,200,000	$ 3,000,000	$ 25,500,000
Common units per share (in USD per share)		$ 33.25	$ 31.75		$ 26.96	$ 31.51	$ 34	$ 26.96
Transaction fees		$ 100,000	$ 200,000		$ 400,000	$ 100,000	$ 100,000
[1]	The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta,Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.
[2]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.

Equity - Public Offering (Detai

Equity - Public Offering (Details) - USD ($) $ / shares in Units, $ in Millions		Sep. 15, 2017	Jun. 09, 2016	May 23, 2016	Mar. 29, 2016	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2016	Sep. 30, 2017		Sep. 30, 2016	[3]
Class of Stock [Line Items]
Units issued in connection with public offering (in shares)									5,275,510
Net proceeds from public offering	[1]								$ 283.7
Contribution from general partner for additional shares issued		$ 2.8
Aggregate percentage of general partner interest									2.00%
Consideration for units issued to our general partner									$ 5.8	[2]	$ 9.8
Shell Treasury Center West Inc | Five Year Revolver
Class of Stock [Line Items]
Debt instrument term		5 years			5 years	5 years		5 years	5 years
Shell Treasury Center West Inc | Five Year Revolver | May 2016 Acquisition
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	364 days
Common Units | May 2016 Acquisition
Class of Stock [Line Items]
Units issued in connection with public offering (in shares)				10,500,000
Net proceeds from public offering				$ 345.8
General Partner
Class of Stock [Line Items]
Units issued in connection with public offering (in shares)		105,510	32,143		258,163				105,510
Aggregate percentage of general partner interest		2.00%	2.00%		2.00%	2.00%	2.00%	2.00%	2.00%
Consideration for units issued to our general partner			$ 1.1		$ 8.2	$ 2.9	$ 0.1	$ 0.5
General Partner | May 2016 Acquisition
Class of Stock [Line Items]
Units issued in connection with public offering (in shares)				214,285
Aggregate percentage of general partner interest				2.00%
Consideration for units issued to our general partner				$ 7.1
General Public | Common Units
Class of Stock [Line Items]
Units issued in connection with public offering (in shares)		5,170,000		1,575,000	12,650,000				5,170,000
Net proceeds from public offering		$ 135.2	51.8		$ 395.1
Gross proceeds from public offering			$ 52.4		$ 401.6
Common units per share (in USD per share)			$ 33.25		$ 31.75	$ 26.96	$ 31.51	$ 34	$ 26.96
Underwriter fees			$ 0.5		$ 6.3
Transaction fees			$ 0.1		$ 0.2	$ 0.4	$ 0.1	$ 0.1
General Public | Common Units | May 2016 Acquisition
Class of Stock [Line Items]
Units issued in connection with public offering (in shares)				10,500,000
Net proceeds from public offering				$ 345.8
Gross proceeds from public offering				$ 349.1
Common units per share (in USD per share)				$ 33.25
Underwriter fees				$ 2.9
Transaction fees				$ 0.4
[1]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.
[2]	The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta,Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.
[3]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.

Equity - Units Outstanding (Det

Equity - Units Outstanding (Details) - shares	Sep. 15, 2017	Jun. 09, 2016	Mar. 29, 2016	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2016	Sep. 30, 2017	Dec. 31, 2016
Class of Stock [Line Items]
Limited partners' capital account, units outstanding (in shares)				187,782,369			187,782,369
Capital units, publicly owned (in shares)				191,614,662			191,614,662	180,936,167
Ownership interest percentage							46.40%
Aggregate percentage of general partner interest							2.00%
General Partner
Class of Stock [Line Items]
Capital units, publicly owned (in shares)				3,832,293			3,832,293	3,618,723
Aggregate percentage of general partner interest	2.00%	2.00%	2.00%	2.00%	2.00%	2.00%	2.00%
General Public | Common Units
Class of Stock [Line Items]
Limited partners' capital account, units outstanding (in shares)				98,832,233			98,832,233	88,367,308
Capital units, publicly owned (in shares)				98,832,233			98,832,233	88,367,308
Shell Pipeline Company L P | Common Units
Class of Stock [Line Items]
Limited partners' capital account, units outstanding (in shares)				88,950,136			88,950,136	21,475,068
Capital units, publicly owned (in shares)				88,950,136			88,950,136	21,475,068

Equity - Schedule of Number of

Equity - Schedule of Number of Units Outstanding (Details) - shares	Sep. 15, 2017	Jun. 09, 2016	May 23, 2016	Mar. 29, 2016	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2016	Sep. 30, 2017
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in shares)								180,936,167
Expiration of subordination period (in shares)								0
Partners' capital account, units, sold in private placement								5,402,985
Units issued in connection with ATM program (in shares)								5,275,510
Ending balance (in shares)					191,614,662			191,614,662
General Partner
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in shares)								3,618,723
Expiration of subordination period (in shares)								0
Partners' capital account, units, sold in private placement					106,122	1,938	15,307	108,060
Units issued in connection with ATM program (in shares)	105,510	32,143		258,163				105,510
Ending balance (in shares)					3,832,293			3,832,293
General Public | Common Units
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in shares)								88,367,308
Expiration of subordination period (in shares)								0
Partners' capital account, units, sold in private placement					5,200,000	94,925	750,000	5,294,925
Units issued in connection with ATM program (in shares)	5,170,000		1,575,000	12,650,000				5,170,000
Ending balance (in shares)					98,832,233			98,832,233
Shell Pipeline Company L P | Common Units
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in shares)								21,475,068
Expiration of subordination period (in shares)								67,475,068
Partners' capital account, units, sold in private placement								0
Units issued in connection with ATM program (in shares)								0
Ending balance (in shares)					88,950,136			88,950,136
Shell Pipeline Company L P | Subordinated Units
Increase (Decrease) in Partners' Capital [Roll Forward]
Beginning balance (in shares)								67,475,068
Expiration of subordination period (in shares)								(67,475,068)
Partners' capital account, units, sold in private placement								0
Units issued in connection with ATM program (in shares)								0
Ending balance (in shares)					0			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 shares per subordinated shares)	1

Equity - Schedule of Distributi

Equity - Schedule of Distributions Declared and/or Paid (Details) - USD ($) $ / shares in Units, $ in Millions	Sep. 15, 2017	Jun. 09, 2016	Mar. 29, 2016	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016		Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2017		Sep. 30, 2016	[1]
Distribution Made To Limited Partner [Line Items]
Aggregate percentage of general partner interest													2.00%
Distributions declared and/or paid				$ 77.4	$ 68.2	$ 63.6	$ 58.6	$ 53.9		$ 49	$ 41.7	$ 35.3
Distributions paid per limited partner unit (in dollars per share)				$ 0.3180	$ 0.30410	$ 0.291	$ 0.27700	$ 0.26375	[1]	$ 0.2500	$ 0.2350	$ 0.2200	$ 0.9131	[2]	$ 0.74880
Shell Pipeline Company L P
Distribution Made To Limited Partner [Line Items]
Distributions declared and/or paid				$ 0	$ 0	$ 0	$ 18.7	$ 17.8		$ 16.9	$ 15.8	$ 14.8
Common Units | General Public
Distribution Made To Limited Partner [Line Items]
Distributions declared and/or paid				31.4	26.9	25.7	24.5	23.3		22	17.9	13.9
Common Units | Shell Pipeline Company L P
Distribution Made To Limited Partner [Line Items]
Distributions declared and/or paid				$ 28.3	$ 27	25.9	5.9	5.7		5.4	$ 5.1	4.7
General Partner
Distribution Made To Limited Partner [Line Items]
Aggregate percentage of general partner interest	2.00%	2.00%	2.00%	2.00%	2.00%						2.00%		2.00%
Distributions declared and/or paid				$ 1.5	$ 1.4	1.3	1.2	1.1		1	$ 0.9	0.7
General Partner | IDR's
Distribution Made To Limited Partner [Line Items]
Distributions declared and/or paid				$ 16.2	$ 12.9	$ 10.7	$ 8.3	$ 6		$ 3.7	$ 2	$ 1.2
[1]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.
[2]	The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.

Equity - Distributions to Nonco

Equity - Distributions to Noncontrolling Interest (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Zydeco Pipeline Company LLC (“Zydeco”)
Class of Stock [Line Items]
Distributions to noncontrolling interest	$ 2	$ 2.7	$ 8.6	$ 17.1

Net Income Per Limited Partne57

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			9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016		Sep. 30, 2017		Sep. 30, 2016
Limited Partners Capital Account [Line Items]
Net income	$ 74.5	$ 61.8	[1]	$ 218.2	[2],[3],[4]	$ 204.5	[1],[5]
Less: Net income attributable to Parent	0	3	[1]	3	[3]	11.4	[1]
Less: Net income attributable to noncontrolling interests	1.9	2.5	[1]	6.3	[3]	17.7	[1]
Net income attributable to the Partnership	72.6	56.3	[1]	208.9	[3]	175.4	[1]
Distributions declared	77.4	53.9		209.2		144.6
Income (less than) / in excess of distributions	(4.8)	2.4		(0.3)		30.8
General Partner
Limited Partners Capital Account [Line Items]
Net income attributable to the Partnership	17.6	7.2		44		15.3
Distributions declared	17.7	7.1		44		14.7
Income (less than) / in excess of distributions	(0.1)	0.1		0		0.6
Limited Partners' Common Units
Limited Partners Capital Account [Line Items]
Net income attributable to the Partnership	55	30.4		164.9		97.4
Distributions declared	59.7	29		165.2		79.4
Income (less than) / in excess of distributions	(4.7)	1.4		(0.3)		18
Limited Partner's Subordinated Units
Limited Partners Capital Account [Line Items]
Net income attributable to the Partnership		18.7				62.7
Distributions declared	$ 0	17.8		$ 0		50.5
Income (less than) / in excess of distributions		$ 0.9				$ 12.2
[1]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.
[2]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.
[3]	The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.
[4]	The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta,Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.
[5]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.

Net Income Per Limited Partne58

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			9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016		Sep. 30, 2017		Sep. 30, 2016
Distribution Made To Limited Partner [Line Items]
Distributions declared	$ 77.4	$ 53.9		$ 209.2		$ 144.6
Income (less than) / in excess of distributions	(4.8)	2.4		(0.3)		30.8
Net income attributable to the Partnership	72.6	56.3	[1]	208.9	[2]	175.4	[1]
General Partner
Distribution Made To Limited Partner [Line Items]
Distributions declared	17.7	7.1		44		14.7
Income (less than) / in excess of distributions	(0.1)	0.1		0		0.6
Net income attributable to the Partnership	17.6	7.2		44		15.3
Limited Partners' Common Units
Distribution Made To Limited Partner [Line Items]
Distributions declared	59.7	29		165.2		79.4
Income (less than) / in excess of distributions	(4.7)	1.4		(0.3)		18
Net income attributable to the Partnership	$ 55	$ 30.4		$ 164.9		$ 97.4
Weighted average units outstanding (in millions):
Weighted average units outstanding, basic and diluted (in shares)	179.2	109.8		178		99.2
Net income per Limited Partner Unit (in dollars):
Net income per Limited Partner unit, basic and diluted (in dollars per share)	$ 0.31	$ 0.28	[1]	$ 0.93	[2]	$ 0.98	[1]
Limited Partner's Subordinated Units
Distribution Made To Limited Partner [Line Items]
Distributions declared	$ 0	$ 17.8		$ 0		$ 50.5
Income (less than) / in excess of distributions		0.9				12.2
Net income attributable to the Partnership		$ 18.7				$ 62.7
Weighted average units outstanding (in millions):
Weighted average units outstanding, basic and diluted (in shares)		67.5				67.5
Net income per Limited Partner Unit (in dollars):
Net income per Limited Partner unit, basic and diluted (in dollars per share)	$ 0	$ 0.28	[1]	$ 0	[2]	$ 0.93	[1]
[1]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.
[2]	The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.

Income Taxes Income Taxes (Deta

Income Taxes Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016		Sep. 30, 2017		Sep. 30, 2016
Income Tax Disclosure [Abstract]
Income tax expense	$ 0	$ 0	[1]	$ 0	[2]	$ 0	[1]
[1]	Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.
[2]	The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Millions	Sep. 01, 2016	Sep. 30, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Accrual for environmental clean-up costs		$ 0	$ 0
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

Oct. 18, 2017

Oct. 17, 2017

Sep. 30, 2017

Jun. 30, 2017

Mar. 31, 2017

Dec. 31, 2016

Sep. 30, 2016

[1]

Jun. 30, 2016

Mar. 31, 2016

Dec. 31, 2015

Sep. 30, 2017

[2]

Sep. 30, 2016

[1]

Subsequent Event [Line Items]

Distributions paid per limited partner unit (in dollars per share)

$ 0.3180

$ 0.30410

$ 0.291

$ 0.27700

$ 0.26375

$ 0.2500

$ 0.2350

$ 0.2200

$ 0.9131

$ 0.74880

Subsequent Event

Subsequent Event [Line Items]

Distributions paid per limited partner unit (in dollars per share)

$ 0.3180

Subsequent Event | Crestwood Basin Interest

Subsequent Event [Line Items]

Ownership

50.00%

Payment for equity interest

$ 49.9

[1]

Prior period financial information has been retrospectively adjusted for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations.

[2]

The financial information for the nine months ended September 30, 2017 reflects adjustments for the acquisition of the Shell Delta, Na Kika and Refinery Gas Pipeline Operations from January 1, 2017 through May 9, 2017.