Spectra Energy Partners 10-Q 3 Aug 17 2017 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	6 Months Ended
	Jun. 30, 2017shares
Document and Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q2
Trading Symbol	SEP
Entity Registrant Name	SPECTRA ENERGY PARTNERS, LP
Entity Central Index Key	1,394,074
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	310,338,509
Entity General Partner, Units Outstanding	6,333,439

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Operating Revenues
Transportation of natural gas	$ 538	$ 475	$ 1,076	$ 959
Transportation of crude oil	100	87	201	173
Storage of natural gas and other	57	56	118	110
Total operating revenues	695	618	1,395	1,242
Operating Expenses
Operating, maintenance and other	209	190	436	369
Depreciation and amortization	87	77	172	154
Property and other taxes	56	46	112	90
Total operating expenses	352	313	720	613
Operating Income	343	305	675	629
Other Income and Expenses
Earnings from equity investments	40	30	78	57
Other income and expenses, net	49	31	94	51
Total other income and expenses	89	61	172	108
Interest Expense	60	56	116	112
Earnings Before Income Taxes	372	310	731	625
Income Tax Expense	5	5	10	9
Net Income	367	305	721	616
Net Income—Noncontrolling Interests	39	18	76	31
Net Income—Controlling Interests	328	287	645	585
Calculation of Limited Partners’ Interest in Net Income:
Net Income—Controlling Interests	328	287	645	585
Less: General partner’s interest in net income	94	76	183	145
Limited partners’ interest in net income	$ 234	$ 211	$ 462	$ 440
Weighted average limited partner units outstanding—basic and diluted	310	298	310	292
Net income per limited partner unit—basic and diluted	$ 0.75	$ 0.71	$ 1.49	$ 1.51
Distributions paid per limited partner unit	$ 0.70125	$ 0.65125	$ 1.39000	$ 1.29000

Condensed Consolidated Stateme3

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Net Income	$ 367	$ 305	$ 721	$ 616
Foreign currency translation adjustments	6	1	7	12
Total Comprehensive Income	373	306	728	628
Less: Comprehensive Income—Noncontrolling Interests	39	18	76	31
Comprehensive Income—Controlling Interests	$ 334	$ 288	$ 652	$ 597

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Current Assets
Cash and cash equivalents	$ 153	$ 216
Receivables, net	334	380
Inventory	40	40
Fuel tracker	13	6
Other	19	18
Total current assets	559	660
Investments and Other Assets
Investments in and loans to unconsolidated affiliates	1,290	1,127
Goodwill	3,236	3,234
Other assets, net	97	108
Total investments and other assets	4,623	4,469
Property, Plant and Equipment
Cost	21,229	19,958
Less accumulated depreciation and amortization	3,972	3,866
Property, plant and equipment, net	17,257	16,092
Regulatory and Other Assets	443	385
Total Assets	22,882	21,606
Current Liabilities
Accounts payable	341	441
Commercial paper	1,324	574
Taxes payable	96	76
Interest payable	79	79
Current portion of long-term debt	408	416
Other	144	193
Total current liabilities	2,392	1,779
Long-term Debt	6,214	6,223
Deferred Credits and Other Liabilities
Deferred income taxes	44	42
Regulatory and other liabilities	154	158
Total deferred credits and other liabilities	198	200
Commitments and Contingencies
Partners’ Capital
Common units (310.3 and 308.4 units issued and outstanding at June 30, 2017 and December 31, 2016, respectively)	11,767	11,650
General partner units (6.3 units issued and outstanding at June 30, 2017 and December 31, 2016)	512	452
Accumulated other comprehensive loss	(38)	(45)
Total partners’ capital	12,241	12,057
Noncontrolling interests	1,837	1,347
Total equity	14,078	13,404
Total Liabilities and Equity	$ 22,882	$ 21,606

Condensed Consolidated Balance5

Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) - shares shares in Millions	Jun. 30, 2017	Dec. 31, 2016
Common units, units issued	310.3	308.4
Common units, units outstanding	310.3	308.4
General partner units, units issued	6.3	6.3
General partner units, units outstanding	6.3	6.3

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
OPERATING ACTIVITIES
Net income	$ 721	$ 616
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	175	158
Deferred income tax expense	2	4
Earnings from equity investments	(78)	(57)
Distributions from equity investments	57	52
Other	(69)	(20)
Net cash provided by operating activities	808	753
INVESTING ACTIVITIES
Capital expenditures	(1,361)	(1,023)
Investments in and loans to unconsolidated affiliates	(158)	(112)
Purchase of intangible, net	0	(40)
Distributions from equity investments	21	45
Distribution to equity investment	0	(148)
Purchases of held-to-maturity securities	(10)	(22)
Proceeds from sales and maturities of held-to-maturity securities	10	22
Purchases of available-for-sale securities	(68)	(315)
Proceeds from sales and maturities of available-for-sale securities	76	316
Other changes in restricted funds	2	4
Other	3	(2)
Net cash used in investing activities	(1,485)	(1,275)
FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	400	0
Payments for the redemption of long-term debt	(416)	(267)
Net increase in commercial paper	750	217
Distributions to noncontrolling interests	(25)	(15)
Contributions from noncontrolling interests	416	278
Proceeds from the issuances of units	87	816
Distributions to partners	(597)	(504)
Other	(1)	0
Net cash provided by financing activities	614	525
Net increase (decrease) in cash and cash equivalents	(63)	3
Cash and cash equivalents at beginning of period	216	168
Cash and cash equivalents at end of period	153	171
Supplemental Information
Property, plant and equipment non-cash accruals	$ 171	$ 225

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Equity (Unaudited) - USD ($) $ in Millions	Total	Limited Partners Common	General Partner	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests
Beginning balance at Dec. 31, 2015	$ 11,346	$ 10,527	$ 336	$ (50)	$ 533
Increase (Decrease) in Equity
Net income	616	440	145		31
Other comprehensive income (loss)	12			12
Attributed deferred tax benefit	24		20		4
Issuances of units	816	800	16
Distributions to partners	(504)	(377)	(127)
Contributions from noncontrolling interests	278				278
Distributions to noncontrolling interests	(15)				(15)
Ending balance at Jun. 30, 2016	12,573	11,390	390	(38)	831
Beginning balance at Dec. 31, 2016	13,404	11,650	452	(45)	1,347
Increase (Decrease) in Equity
Net income	721	462	183		76
Other comprehensive income (loss)	7			7
Attributed deferred tax benefit	65		42		23
Issuances of units	87	85	2
Distributions to partners	(597)	(430)	(167)
Contributions from noncontrolling interests	416				416
Distributions to noncontrolling interests	(25)				(25)
Ending balance at Jun. 30, 2017	$ 14,078	$ 11,767	$ 512	$ (38)	$ 1,837

General

General	6 Months Ended
	Jun. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
General	General The terms “we,” “our,” “us” and “Spectra Energy Partners” as used in this report refer collectively to Spectra Energy Partners, LP and its subsidiaries unless the context suggests otherwise. These terms are used for convenience only and are not intended as a precise description of any separate legal entity within Spectra Energy Partners. Nature of Operations. Spectra Energy Partners, through its subsidiaries and equity affiliates, is engaged in the transmission, storage and gathering of natural gas and the transportation and storage of crude oil through interstate pipeline systems. We are a Delaware master limited partnership. We manage our business in two reportable segments: U.S. Transmission and Liquids. The U.S. Transmission segment provides interstate transmission, storage and gathering of natural gas. The Liquids segment provides transportation of crude oil. On February 27, 2017, Enbridge Inc. (Enbridge) and Spectra Energy Corp (Spectra Energy) completed a merger transaction (the Merger) resulting in Spectra Energy being a wholly owned subsidiary of Enbridge. As a result of the Merger, we became an indirect subsidiary of Enbridge through Enbridge’s ownership of Spectra Energy. As of June 30, 2017 , Enbridge and its subsidiaries collectively owned a 75% ownership interest in us (a 73% limited partner interest and a 2% general partner interest), together with 100% of our incentive distribution rights, and the remaining 25% limited partner interest was publicly owned. Basis of Presentation. The accompanying condensed consolidated financial statements have been prepared in accordance with generally accepted accounting principles in the United States of America (U.S. GAAP) for interim consolidated financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. They do not include all the information and notes required by U.S. GAAP for annual consolidated financial statements and should therefore be read in conjunction with our annual consolidated financial statements and notes presented in our Annual Report on Form 10-K for the year ended December 31, 2016 . In the opinion of management, the condensed consolidated financial statements contain all adjustments, consisting only of normal recurring adjustments, necessary to present fairly our financial position, results of operations and cash flows for the interim periods reported. These condensed consolidated financial statements follow the same significant accounting policies as those included in our annual consolidated financial statements for the year ended December 31, 2016 , except for the adoption of new standards. See Note 14 for additional information on the adoption of new standards. Our operations and earnings for interim periods can be affected by seasonal fluctuations in the supply of and demand for natural gas, and may not be indicative of annual results.

Business Segments

Business Segments	6 Months Ended
	Jun. 30, 2017
Segment Reporting [Abstract]
Business Segments	We manage our business in two reportable segments: U.S. Transmission and Liquids. The remainder of our business operations is presented as “Other,” and consists of certain corporate costs. Condensed Consolidated Statements of Operations Total Operating Revenues Depreciation and Amortization Segment EBITDA/Consolidated Earnings Before Income Taxes (in millions) Three Months Ended June 30, 2017 U.S. Transmission $ 592 $ 79 $ 480 Liquids 103 8 64 Total reportable segments 695 87 544 Other — — (25 ) Depreciation and amortization — — 87 Interest expense — — 60 Total consolidated $ 695 $ 87 $ 372 Three Months Ended June 30, 2016 U.S. Transmission $ 529 $ 69 $ 406 Liquids 89 8 58 Total reportable segments 618 77 464 Other — — (22 ) Depreciation and amortization — — 77 Interest expense — — 56 Interest income and other — — 1 Total consolidated $ 618 $ 77 $ 310 Six Months Ended June 30, 2017 U.S. Transmission $ 1,188 $ 156 $ 959 Liquids 207 16 130 Total reportable segments 1,395 172 1,089 Other — — (71 ) Depreciation and amortization — 172 Interest expense — — 116 Interest income and other — — 1 Total consolidated $ 1,395 $ 172 $ 731 Six Months Ended June 30, 2016 U.S. Transmission $ 1,067 $ 139 $ 817 Liquids 175 15 114 Total reportable segments 1,242 154 931 Other — — (42 ) Depreciation and amortization — — 154 Interest expense — — 112 Interest income and other — — 2 Total consolidated $ 1,242 $ 154 $ 625

Net Income Per Limited Partner

Net Income Per Limited Partner Unit and Cash Distributions	6 Months Ended
	Jun. 30, 2017
Equity [Abstract]
Net Income Per Limited Partner Unit and Cash Distributions	Net Income Per Limited Partner Unit and Cash Distributions We determined basic and diluted net income per limited partner unit as follows: Three Months Ended Six Months Ended 2017 2016 2017 2016 (in millions, except per unit amounts) Net income—controlling interests $ 328 $ 287 $ 645 $ 585 Less: Net income attributable to: General partner’s interest in general partner units—2% 7 6 13 12 General partner’s interest in incentive distribution rights 87 70 170 133 Limited partners’ interest in net income attributable to common units $ 234 $ 211 $ 462 $ 440 Weighted average limited partner units outstanding—basic and diluted 310 298 310 292 Net income per limited partner unit—basic and diluted $ 0.75 $ 0.71 $ 1.49 $ 1.51 Our partnership agreement requires that, within 60 days after the end of each quarter, we distribute all of our Available Cash, as defined, to unitholders of record on the applicable record date. Available Cash. Available Cash, for any quarter, consists of all cash and cash equivalents on hand at the end of that quarter: • less the amount of cash reserves established by the general partner to: • provide for the proper conduct of business, • comply with applicable law, any debt instrument or other agreement, or • provide funds for minimum quarterly distributions to the unitholders and to the general partner for any one or more of the next four quarters, • plus, if the general partner so determines, all or a portion of cash and cash equivalents on hand on the date of determination of Available Cash for the quarter. Incentive Distribution Rights. The general partner holds incentive distribution rights beyond the first target distribution in accordance with the partnership agreement as follows: Marginal Percentage Interest in Distributions Distribution Targets Portion of Quarterly Distribution Per Common Unit Common Unitholders General Partner Minimum Quarterly Distribution $0.30 98 % 2 % First Target Distribution above $0.30 up to $0.345 98 % 2 % Second Target Distribution above $0.345 up to $0.375 85 % 15 % Third Target Distribution above $0.375 up to $0.45 75 % 25 % Thereafter above $0.45 50 % 50 % To the extent these incentive distributions are made to the general partner, there will be more Available Cash proportionately allocated to our general partner than to holders of common units. A cash distribution of $0.71375 per limited partner unit was declared on August 2, 2017 and is payable on August 29, 2017 to unitholders of record at the close of business on August 15, 2017 . There is a reduction in the aggregate quarterly distributions, if any, to Spectra Energy, (as indirect holder of incentive distribution rights), by $4 million per quarter for a period of 12 consecutive quarters commencing with the quarter ending on December 31, 2015 through the quarter ending on September 30, 2018. The reduction of distributions is a result of the sale of our interests in DCP Sand Hills Pipeline, LLC (Sand Hills) and DCP Southern Hills Pipeline, LLC (Southern Hills) to Spectra Energy in October 2015.

Variable Interest Entities

Variable Interest Entities	6 Months Ended
	Jun. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entity Disclosure	Variable Interest Entities Sabal Trail. In April 2016, NextEra Energy, Inc. (NextEra) purchased a 9.5% interest in Sabal Trail Transmission, LLC (Sabal Trail) from us. See Note 5 for additional information related to this transaction. As of June 30, 2017 , we owned a 50% interest in Sabal Trail, a joint venture that is constructing a natural gas pipeline to transport natural gas to Florida. Sabal Trail is a variable interest entity (VIE) due to insufficient equity at risk to finance its activities. We determined that we are the primary beneficiary because we direct the activities of Sabal Trail that most significantly impact its economic performance and we consolidate Sabal Trail in our financial statements. The current estimate of the total remaining construction cost is approximately $0.4 billion . The following summarizes assets and liabilities for Sabal Trail: Condensed Consolidated Balance Sheets June 30, 2017 December 31, 2016 (in millions) Assets Current assets $ 95 $ 165 Net property, plant and equipment 2,844 1,942 Regulatory assets and deferred debits 126 79 Total Assets $ 3,065 $ 2,186 Liabilities and Equity Current liabilities $ 140 $ 239 Equity 2,925 1,947 Total Liabilities and Equity $ 3,065 $ 2,186 See Note 15 for a subsequent event related to Sabal Trail. Nexus. We own a 50% interest in Nexus Gas Transmission, LLC (Nexus), a joint venture that is constructing a natural gas pipeline from Ohio to Michigan and continuing on to Ontario, Canada. Nexus is a VIE due to insufficient equity at risk to finance its activities. We determined that we are not the primary beneficiary because the power to direct the activities of Nexus that most significantly impact its economic performance is shared. We account for Nexus under the equity method. Our maximum exposure to loss is $1.0 billion . We have an investment in Nexus of $510 million and $356 million as of June 30, 2017 and December 31, 2016 , respectively, classified as Investments in and Loans to Unconsolidated Affiliates on our Condensed Consolidated Balance Sheets. In December 2016, we issued performance guarantees to a third party and an affiliate on behalf of Nexus. See Note 12 for further discussion of the guarantee arrangement. PennEast Pipeline. In June 2017, we purchased an additional 10% in PennEast Pipeline (PennEast) from PSEG Power Gas Holdings, LLC, increasing our ownership interest in PennEast to 20% . PennEast is a joint venture that is constructing a natural gas pipeline originating in northeastern Pennsylvania, and ending near Pennington, Mercer County, New Jersey. PennEast is a VIE due to insufficient equity at risk to finance its activities. We determined that we are not the primary beneficiary because the power to direct the activities of PennEast that most significantly impact its economic performance is shared. We account for PennEast under the equity method. Our maximum exposure to loss is $273 million . We have an investment in PennEast of $43 million and $11 million as of June 30, 2017 and December 31, 2016 , respectively, classified as Investments in and Loans to Unconsolidated Affiliates on our Condensed Consolidated Balance Sheets.

Intangible Asset

Intangible Asset	6 Months Ended
	Jun. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets Disclosure	Intangible Asset During the first quarter of 2016 we entered into a project coordination agreement (PCA) with NextEra, Duke Energy Corporation and Williams Partners L.P. In accordance with the agreement, payments will be made, based on our proportional ownership interest in the Sabal Trail project, as certain milestones of the project are met. During the first quarter of 2016, the first milestone was achieved and paid, consisting of $48 million . In April 2016, NextEra purchased an additional 9.5% interest in Sabal Trail, reducing our ownership interest in Sabal Trail to 50% . Upon purchase of the additional ownership interest, NextEra reimbursed us $8 million for NextEra’s proportional share of the first milestone payment, which reduced our total milestone payments to $40 million as of June 2016. During the third quarter of 2016, the second milestone was achieved and paid, consisting of an additional payment of $40 million , for total milestone payments of $80 million as of June 30, 2017. Both payments are classified as Investing Activities — Purchase of Intangible, Net. This PCA is an intangible asset and is classified as Investments and Other Assets — Other Assets, Net on our Condensed Consolidated Balance Sheet. The intangible asset will be amortized over a period of 25 years beginning at the time of in-service of Sabal Trail, which is expected to occur during the third quarter of 2017.

Goodwill

Goodwill	6 Months Ended
	Jun. 30, 2017
Goodwill Disclosure [Abstract]
Goodwill Disclosure	Goodwill We perform our goodwill impairment test annually and evaluate goodwill when events or changes in circumstances indicate that its carrying value may not be recoverable. We completed our annual goodwill impairment test as of April 1, 2017 and no impairments were identified. We perform our annual review for goodwill impairment at the reporting unit level, which is identified by assessing whether the components of our operating segments constitute businesses for which discrete financial information is available, whether segment management regularly reviews the operating results of those components and whether the economic and regulatory characteristics are similar. We determined that our reporting units are equivalent to our reportable segments. As permitted under accounting guidance on testing goodwill for impairment, we perform either a qualitative assessment or a quantitative assessment of each of our reporting units based on management’s judgment. With respect to our qualitative assessments, we consider events and circumstances specific to us, such as macroeconomic conditions, industry and market considerations, cost factors and overall financial performance, when evaluating whether it is more likely than not that the fair values of our reporting units are less than their respective carrying amounts.

Marketable Securities and Restr

Marketable Securities and Restricted Funds	6 Months Ended
	Jun. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Marketable Securities and Restricted Funds	Marketable Securities and Restricted Funds We routinely invest excess cash and various restricted balances in securities such as commercial paper, corporate debt securities, and other money market securities in the United States, as well as equity securities in Canada. We do not purchase marketable securities for speculative purposes, therefore we do not have any securities classified as trading securities. While we do not routinely sell marketable securities prior to their scheduled maturity dates, some of our investments may be held and restricted for the purposes of funding future capital expenditures and National Energy Board (NEB) regulatory requirements, so these investments are classified as available-for-sale (AFS) marketable securities as they may occasionally be sold prior to their scheduled maturity dates due to the unexpected timing of cash needs. Initial investments in securities are classified as purchases of the respective type of securities (AFS marketable securities or held-to-maturity (HTM) marketable securities). Maturities of securities are classified within proceeds from sales and maturities of securities in the Condensed Consolidated Statements of Cash Flows. AFS Securities . We had $2 million and $10 million of AFS securities classified as Investments and Other Assets — Other Assets, Net on the Condensed Consolidated Balance Sheets as of June 30, 2017 and December 31, 2016 , respectively. These investments include $2 million and $1 million of restricted funds held and collected from customers for Canadian pipeline abandonment in accordance with the NEB's regulatory requirements, as of June 30, 2017 and December 31, 2016 , respectively, as well as $9 million of restricted funds related to certain construction projects as of December 31, 2016. At June 30, 2017 , the weighted-average contractual maturity of outstanding AFS securities was less than one year . There were no material gross unrecognized holding gains or losses associated with investments in AFS securities at June 30, 2017 or December 31, 2016 . HTM Securities . All of our HTM securities are restricted funds. We had $3 million of money market securities classified as Current Assets — Other on the Condensed Consolidated Balance Sheets as of June 30, 2017 and December 31, 2016 , respectively. These securities are restricted pursuant to certain Express-Platte pipeline system (Express-Platte) debt agreements. At June 30, 2017 , the weighted-average contractual maturity of outstanding HTM securities was less than one year . There were no material gross unrecognized holding gains or losses associated with investments in HTM securities at June 30, 2017 or December 31, 2016 . Other Restricted Funds . In addition to the AFS and HTM securities that were restricted funds as described above, we had other restricted funds totaling $3 million and $5 million classified as Investments and Other Assets — Other Assets, Net on the Condensed Consolidated Balance Sheets at June 30, 2017 and December 31, 2016 , respectively. These restricted funds are related to certain construction projects. Changes in restricted balances are presented within Investing Activities on our Condensed Consolidated Statements of Cash Flows.

Debt and Credit Facility

Debt and Credit Facility	6 Months Ended
	Jun. 30, 2017
Debt Disclosure [Abstract]
Debt and Credit Facility	Debt Credit Facility Maturity Date Total Facility Commercial Paper Outstanding at June 30, 2017 Available (in millions) Spectra Energy Partners, LP 2021 $ 2,500 $ 1,324 $ 1,176 The issuances of commercial paper, letters of credit and revolving borrowings reduce the amount available under the credit facility. As of June 30, 2017 , there were no letters of credit issued or revolving borrowings outstanding under the credit facility. Our credit agreements contain various covenants. Failure to meet those covenants beyond applicable grace periods could result in accelerated due dates and/or termination of the agreements. We were in compliance with these covenants as of June 30, 2017 . In addition, our credit agreements allow for acceleration of payments or termination of the agreements due to nonpayment, or in some cases, due to the acceleration of our other significant indebtedness or other significant indebtedness of some of our subsidiaries. Our debt and credit agreements do not contain provisions that trigger an acceleration of indebtedness based solely on the occurrence of a material adverse change in our financial condition or results of operations. Debt Issuances . On June 7, 2017, we issued $400 million variable-rate senior unsecured note due in 2020. Net proceeds from the offering were used to fully repay and terminate the variable-rate senior unsecured term loan due in November 2018.

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The following presents, for each of the fair value hierarchy levels, assets that are measured at fair value on a recurring basis as of June 30, 2017 and December 31, 2016 : Description Condensed Consolidated Balance Sheet Caption June 30, 2017 Total Level 1 Level 2 Level 3 (in millions) Corporate debt securities Cash and cash equivalents $ 59 $ — $ 59 $ — Canadian equity securities Investments and other assets — other assets, net 2 2 — — Interest rate swaps Investments and other assets — other assets, net 8 — 8 — Total Assets $ 69 $ 2 $ 67 $ — Description Condensed Consolidated Balance Sheet Caption December 31, 2016 Total Level 1 Level 2 Level 3 (in millions) Corporate debt securities Cash and cash equivalents $ 145 $ — $ 145 $ — Corporate debt securities Investments and other assets — other assets, net 9 — 9 — Canadian equity securities Investments and other assets — other assets, net 1 1 — — Interest rate swaps Investments and other assets — other assets, net 9 — 9 — Total Assets $ 164 $ 1 $ 163 $ — Level 1 Level 1 valuations represent quoted unadjusted prices for identical instruments in active markets. Level 2 Valuation Techniques Fair values of our financial instruments that are actively traded in the secondary market, including our long-term debt, are determined based on market-based prices. These valuations may include inputs such as quoted market prices of the exact or similar instruments, broker or dealer quotations, or alternative pricing sources that may include models or matrix pricing tools, with reasonable levels of price transparency. For interest rate swaps, we utilize data obtained from a third-party source for the determination of fair value. Both the future cash flows for the fixed-leg and floating-leg of our swaps are discounted to present value. Level 3 Valuation Techniques Level 3 valuation techniques include the use of pricing models, discounted cash flow methodologies or similar techniques where at least one significant model assumption or input is unobservable. Level 3 financial instruments also include those for which the determination of fair value requires significant management judgment or estimation. Financial Instruments The fair values of financial instruments that are recorded and carried at book value are summarized in the following table. Judgment is required in interpreting market data to develop the estimates of fair value. These estimates are not necessarily indicative of the amounts we could have realized in current markets. June 30, 2017 December 31, 2016 Book Value Approximate Fair Value Book Value Approximate Fair Value (in millions) Note receivable, noncurrent (a) $ 71 $ 71 $ 71 $ 71 Long-term debt, including current maturities (b) 6,656 6,980 6,672 6,855 ________ (a) Included within Investments in and Loans to Unconsolidated Affiliates. (b) Excludes commercial paper, unamortized items and fair value hedge carrying value adjustments. The fair value of our long-term debt is determined based on market-based prices as described in the Level 2 valuation technique described above and is classified as Level 2. The fair values of cash and cash equivalents, restricted cash, short-term investments, accounts receivable, note receivable-noncurrent, accounts payable, commercial paper and short-term money market securities are not materially different from their carrying amounts because of the short-term nature of these instruments or because the stated rates approximate market rates. During the six months ended June 30, 2017 and 2016 , there were no material adjustments to assets and liabilities measured at fair value on a nonrecurring basis.

Risk Management and Hedging Act

Risk Management and Hedging Activities	6 Months Ended
	Jun. 30, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Risk Management and Hedging Activities	Risk Management and Hedging Activities Changes in interest rates expose us to risk as a result of our issuance of variable and fixed-rate debt and commercial paper. We are exposed to foreign currency risk from the Canadian portion of Express-Platte. We employ established policies and procedures to manage our risks associated with these market fluctuations, which may include the use of derivatives, mostly around interest rate exposures. For interest rate derivative instruments that are designated and qualify as fair value hedges, the gain or loss on the derivative as well as the offsetting loss or gain on the hedged item attributable to the hedged risk is recognized in the Condensed Consolidated Statements of Operations. There were no significant amounts of gains or losses recognized in net income during the six months ended June 30, 2017 . At June 30, 2017 , we had “pay floating — receive fixed” interest rate swaps outstanding with a total notional amount of $900 million to hedge against changes in the fair value of our fixed-rate debt that arise as a result of changes in market interest rates . These swaps also allow us to transform a portion of the underlying interest payments related to our long-term fixed-rate debt securities into variable-rate interest payments in order to achieve our desired mix of fixed and variable-rate debt. Information about our interest rate swaps that had netting or rights of offset arrangements are as follows: June 30, 2017 December 31, 2016 Gross Amounts Presented in the Condensed Consolidated Balance Sheet Amounts Not Offset in the Condensed Consolidated Balance Sheet Net Amount Gross Amounts Presented in the Condensed Consolidated Balance Sheet Amounts Not Offset in the Condensed Consolidated Balance Sheet Net Amount Description (in millions) Assets $ 8 $ — $ 8 $ 9 $ — $ 9

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Environmental We are subject to various U.S. federal, state and local laws and regulations, as well as Canadian federal and provincial laws, relating to the protection of the environment. These laws and regulations can change from time to time, imposing new obligations on us. Environmental risk is inherent to liquid hydrocarbon and natural gas pipeline operations, and we and our affiliates are, at times, subject to environmental remediation at various contaminated sites. We manage this environmental risk through appropriate environmental policies and practices to minimize any impact our operations may have on the environment. To the extent that we are unable to recover payment for environmental liabilities from insurance or other potentially responsible parties, we will be responsible for payment of liabilities arising from environmental incidents associated with the operating activities of our liquids and natural gas businesses. Litigation We are subject to various legal and regulatory actions and proceedings which arise in the normal course of business, including interventions in regulatory proceedings and challenges to regulatory approvals and permits by special interest groups. While the final outcome of such actions and proceedings cannot be predicted with certainty, management believes that the resolution of such actions and proceedings will not have a material impact on our interim consolidated financial position or results of operations.

Guarantees

Guarantees	6 Months Ended
	Jun. 30, 2017
Guarantees [Abstract]
Guarantees	Guarantees We have various financial guarantees which are issued in the normal course of business. We enter into these arrangements to facilitate a commercial transaction with a third party by enhancing the value of the transaction to the third party. To varying degrees, these guarantees involve elements of performance and credit risk, which are not included on our Condensed Consolidated Balance Sheets. The possibility of having to perform under these guarantees is largely dependent upon future operations of various subsidiaries, investees and other third parties, or the occurrence of certain future events. In December 2016, we issued performance guarantees to a third party and an affiliate on behalf of an equity method investee. These guarantees were issued to enable the equity method investee to enter into long-term transportation contracts with the third party. While the likelihood is remote, the maximum potential amount of future payments we could have been required to make as of June 30, 2017 was $73 million . These performance guarantees expire in 2032 . As of June 30, 2017, the amounts recorded for the guarantees described above are not material, both individually and in the aggregate.

Issuances of Common Units

Issuances of Common Units	6 Months Ended
	Jun. 30, 2017
Issuances of Common Units [Abstract]
Issuances of Common Units	Issuances of Common Units During the six months ended June 30, 2017 , we issued 1.9 million common units to the public under our at-the-market program, and approximately 40,000 general partner units to our general partner in order for it to maintain a 2% general partner interest. Total net proceeds were $87 million , including approximately $2 million of proceeds from our general partner.

New Accounting Pronouncements

New Accounting Pronouncements	6 Months Ended
	Jun. 30, 2017
Accounting Changes and Error Corrections [Abstract]
New Accounting Pronouncements	New Accounting Pronouncements ADOPTION OF NEW STANDARDS Simplifying the Measurement of Goodwill Impairment Effective January 1, 2017, we early adopted Accounting Standards Update (ASU) 2017-04 and applied the standard on a prospective basis. Under the new guidance, goodwill impairment will now be the amount by which a reporting unit’s carrying value exceeds its fair value; this amount should not exceed the carrying amount of goodwill. The adoption of the pronouncement did not have a material impact on our consolidated financial statements. Clarifying the Definition of a Business in an Acquisition Effective January 1, 2017, we early adopted ASU 2017-01 on a prospective basis. The new standard was issued with the objective of adding guidance to assist entities with evaluating whether transactions should be accounted for as acquisitions (disposals) of assets or businesses. The adoption of the pronouncement did not have a material impact on our consolidated financial statements. Accounting for Intra-Entity Asset Transfers Effective January 1, 2017, we early adopted ASU 2016-16 on a modified retrospective basis. The new standard was issued with the intent of improving the accounting for the income tax consequences of intra-entity asset transfers other than inventory. Under the new guidance, an entity should recognize the income tax consequences of an intra-entity transfer of an asset, other than inventory, when the transfer occurs. The adoption of the pronouncement did not have a material impact on our consolidated financial statements. Simplifying the Embedded Derivatives Analysis for Debt Instruments Effective January 1, 2017, we adopted ASU 2016-06 on a modified retrospective basis. The new guidance simplifies the embedded derivative analysis for debt instruments containing contingent call or put options. The adoption of the pronouncement did not have a material impact on our consolidated financial statements. FUTURE ACCOUNTING POLICY CHANGES Clarifying Guidance on Derecognition and Partial Sales of Nonfinancial Assets ASU 2017-05 was issued in February 2017 with the intent of clarifying the scope of asset derecognition guidance and accounting for partial sales of nonfinancial assets. The ASU clarifies the scope provisions of nonfinancial assets and how to allocate consideration to each distinct asset, and amends the guidance for derecognition of a distinct nonfinancial asset in partial sale transactions. We are currently assessing the impact of the new standard on the consolidated financial statements. The accounting update is effective for annual and interim periods beginning after December 15, 2017 and is to be applied on a retrospective or modified retrospective basis. Accounting for Credit Losses ASU 2016-13 was issued in June 2016 with the intent of providing financial statement users with more useful information about the expected credit losses on financial instruments and other commitments to extend credit held by a reporting entity at each reporting date. Current treatment uses the incurred loss methodology for recognizing credit losses that delays the recognition until it is probable a loss has been incurred. The amendment adds a new impairment model, known as the current expected credit loss model that is based on expected losses rather than incurred losses. Under the new guidance, an entity recognizes as an allowance its estimate of expected credit losses, which the Financial Accounting Standards Board believes will result in more timely recognition of such losses. We are currently assessing the impact of the new standard on its consolidated financial statements. The accounting update is effective for annual and interim periods beginning on or after December 15, 2019 and is to be applied using a modified retrospective approach. Recognition of Leases ASU 2016-02 was issued in February 2016 with the intent to increase transparency and comparability among organizations. It requires lessees of operating lease arrangements to recognize lease assets and lease liabilities on the statement of financial position and disclose additional key information about lease agreements. The accounting update also replaces the current definition of a lease and requires that an arrangement be recognized as a lease when a customer has the right to obtain substantially all of the economic benefits from the use of an asset, as well as the right to direct the use of the asset. We are currently assessing the impact of the new standard on its consolidated financial statements. The accounting update is effective for fiscal years beginning after December 15, 2018 and is to be applied using a modified retrospective approach. Revenue from Contracts with Customers ASU 2014-09 was issued in 2014 with the intent of significantly enhancing consistency and comparability of revenue recognition practices across entities and industries. The new standard establishes a single, principles-based five-step model to be applied to all contracts with customers and introduces new and enhanced disclosure requirements. The standard is effective January 1, 2018. The new revenue standard permits either a full retrospective method of adoption with restatement of all prior periods presented, or a modified retrospective method with the cumulative effect of applying the new standard recognized as an adjustment to opening retained earnings in the period of adoption. We have tentatively decided to adopt the new revenue standard using the modified retrospective method. We have reviewed a sample of our revenue contracts in order to evaluate the effect of the new standard on our revenue recognition practices. Based on our initial assessment, estimates of variable consideration which will be required under the new standard for certain Liquids Pipelines, and U.S. Transmission revenue contracts as well as the allocation of the transaction price for certain Liquids Pipelines revenue contracts, may result in changes to the pattern or timing of revenue recognition for those contracts. While we have not yet completed the assessment, we do not expect these changes will have a material impact on revenue or earnings (loss). We are currently developing processes to generate the disclosures required under the new standard.

Subsequent Events

Subsequent Events	6 Months Ended
	Jun. 30, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On July 3, 2017, Sabal Trail was placed into service. During July, we determined that we are no longer the primary beneficiary because the power to direct the activities of Sabal Trail is now shared. We have deconsolidated Sabal Trail and will begin accounting for Sabal Trail under the equity method. See Note 4 for a summary of assets and liabilities included in our Condensed Consolidated Balance Sheets.

Summary of Operations and Signi

Summary of Operations and Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2017
Accounting Policies [Abstract]
Goodwill and Intangible Assets, Goodwill, Policy	We perform our goodwill impairment test annually and evaluate goodwill when events or changes in circumstances indicate that its carrying value may not be recoverable. We completed our annual goodwill impairment test as of April 1, 2017 and no impairments were identified. We perform our annual review for goodwill impairment at the reporting unit level, which is identified by assessing whether the components of our operating segments constitute businesses for which discrete financial information is available, whether segment management regularly reviews the operating results of those components and whether the economic and regulatory characteristics are similar. We determined that our reporting units are equivalent to our reportable segments. As permitted under accounting guidance on testing goodwill for impairment, we perform either a qualitative assessment or a quantitative assessment of each of our reporting units based on management’s judgment. With respect to our qualitative assessments, we consider events and circumstances specific to us, such as macroeconomic conditions, industry and market considerations, cost factors and overall financial performance, when evaluating whether it is more likely than not that the fair values of our reporting units are less than their respective carrying amounts.
Derivatives, Offsetting Fair Value Amounts, Policy	For interest rate derivative instruments that are designated and qualify as fair value hedges, the gain or loss on the derivative as well as the offsetting loss or gain on the hedged item attributable to the hedged risk is recognized in the Condensed Consolidated Statements of Operations.
Fair Value Measurement, Policy	Level 1 Level 1 valuations represent quoted unadjusted prices for identical instruments in active markets. Level 2 Valuation Techniques Fair values of our financial instruments that are actively traded in the secondary market, including our long-term debt, are determined based on market-based prices. These valuations may include inputs such as quoted market prices of the exact or similar instruments, broker or dealer quotations, or alternative pricing sources that may include models or matrix pricing tools, with reasonable levels of price transparency. For interest rate swaps, we utilize data obtained from a third-party source for the determination of fair value. Both the future cash flows for the fixed-leg and floating-leg of our swaps are discounted to present value. Level 3 Valuation Techniques Level 3 valuation techniques include the use of pricing models, discounted cash flow methodologies or similar techniques where at least one significant model assumption or input is unobservable. Level 3 financial instruments also include those for which the determination of fair value requires significant management judgment or estimation.
Sabal Trail
Variable Interest Entity [Line Items]
Consolidation, Variable Interest Entity, Policy	Sabal Trail is a variable interest entity (VIE) due to insufficient equity at risk to finance its activities. We determined that we are the primary beneficiary because we direct the activities of Sabal Trail that most significantly impact its economic performance and we consolidate Sabal Trail in our financial statements.
Nexus
Variable Interest Entity [Line Items]
Consolidation, Variable Interest Entity, Policy	Nexus is a VIE due to insufficient equity at risk to finance its activities. We determined that we are not the primary beneficiary because the power to direct the activities of Nexus that most significantly impact its economic performance is shared. We account for Nexus under the equity method.

Business Segments (Tables)

Business Segments (Tables)	6 Months Ended
	Jun. 30, 2017
Segment Reporting [Abstract]
Business Segment Data	Condensed Consolidated Statements of Operations Total Operating Revenues Depreciation and Amortization Segment EBITDA/Consolidated Earnings Before Income Taxes (in millions) Three Months Ended June 30, 2017 U.S. Transmission $ 592 $ 79 $ 480 Liquids 103 8 64 Total reportable segments 695 87 544 Other — — (25 ) Depreciation and amortization — — 87 Interest expense — — 60 Total consolidated $ 695 $ 87 $ 372 Three Months Ended June 30, 2016 U.S. Transmission $ 529 $ 69 $ 406 Liquids 89 8 58 Total reportable segments 618 77 464 Other — — (22 ) Depreciation and amortization — — 77 Interest expense — — 56 Interest income and other — — 1 Total consolidated $ 618 $ 77 $ 310 Six Months Ended June 30, 2017 U.S. Transmission $ 1,188 $ 156 $ 959 Liquids 207 16 130 Total reportable segments 1,395 172 1,089 Other — — (71 ) Depreciation and amortization — 172 Interest expense — — 116 Interest income and other — — 1 Total consolidated $ 1,395 $ 172 $ 731 Six Months Ended June 30, 2016 U.S. Transmission $ 1,067 $ 139 $ 817 Liquids 175 15 114 Total reportable segments 1,242 154 931 Other — — (42 ) Depreciation and amortization — — 154 Interest expense — — 112 Interest income and other — — 2 Total consolidated $ 1,242 $ 154 $ 625

Net Income Per Limited Partne25

Net Income Per Limited Partner Unit and Cash Distributions (Tables)	6 Months Ended
	Jun. 30, 2017
Equity [Abstract]
Net Income Per Limited Partner Unit Calculations	: Three Months Ended Six Months Ended 2017 2016 2017 2016 (in millions, except per unit amounts) Net income—controlling interests $ 328 $ 287 $ 645 $ 585 Less: Net income attributable to: General partner’s interest in general partner units—2% 7 6 13 12 General partner’s interest in incentive distribution rights 87 70 170 133 Limited partners’ interest in net income attributable to common units $ 234 $ 211 $ 462 $ 440 Weighted average limited partner units outstanding—basic and diluted 310 298 310 292 Net income per limited partner unit—basic and diluted $ 0.75 $ 0.71 $ 1.49 $ 1.51
Incentive Distribution Rights in Accordance with Partnership Agreement	Incentive Distribution Rights. The general partner holds incentive distribution rights beyond the first target distribution in accordance with the partnership agreement as follows: Marginal Percentage Interest in Distributions Distribution Targets Portion of Quarterly Distribution Per Common Unit Common Unitholders General Partner Minimum Quarterly Distribution $0.30 98 % 2 % First Target Distribution above $0.30 up to $0.345 98 % 2 % Second Target Distribution above $0.345 up to $0.375 85 % 15 % Third Target Distribution above $0.375 up to $0.45 75 % 25 % Thereafter above $0.45 50 % 50 %

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	6 Months Ended
	Jun. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Variable Interest Entities	The following summarizes assets and liabilities for Sabal Trail: Condensed Consolidated Balance Sheets June 30, 2017 December 31, 2016 (in millions) Assets Current assets $ 95 $ 165 Net property, plant and equipment 2,844 1,942 Regulatory assets and deferred debits 126 79 Total Assets $ 3,065 $ 2,186 Liabilities and Equity Current liabilities $ 140 $ 239 Equity 2,925 1,947 Total Liabilities and Equity $ 3,065 $ 2,186

Debt and Credit Facility (Table

Debt and Credit Facility (Tables)	6 Months Ended
	Jun. 30, 2017
Debt Disclosure [Abstract]
Debt and Credit Facility Summary	Credit Facility Maturity Date Total Facility Commercial Paper Outstanding at June 30, 2017 Available (in millions) Spectra Energy Partners, LP 2021 $ 2,500 $ 1,324 $ 1,176

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following presents, for each of the fair value hierarchy levels, assets that are measured at fair value on a recurring basis as of June 30, 2017 and December 31, 2016 : Description Condensed Consolidated Balance Sheet Caption June 30, 2017 Total Level 1 Level 2 Level 3 (in millions) Corporate debt securities Cash and cash equivalents $ 59 $ — $ 59 $ — Canadian equity securities Investments and other assets — other assets, net 2 2 — — Interest rate swaps Investments and other assets — other assets, net 8 — 8 — Total Assets $ 69 $ 2 $ 67 $ — Description Condensed Consolidated Balance Sheet Caption December 31, 2016 Total Level 1 Level 2 Level 3 (in millions) Corporate debt securities Cash and cash equivalents $ 145 $ — $ 145 $ — Corporate debt securities Investments and other assets — other assets, net 9 — 9 — Canadian equity securities Investments and other assets — other assets, net 1 1 — — Interest rate swaps Investments and other assets — other assets, net 9 — 9 — Total Assets $ 164 $ 1 $ 163 $ —
Fair Values of Financial Instruments That are Recorded and Carried at Book Value	The fair values of financial instruments that are recorded and carried at book value are summarized in the following table. Judgment is required in interpreting market data to develop the estimates of fair value. These estimates are not necessarily indicative of the amounts we could have realized in current markets. June 30, 2017 December 31, 2016 Book Value Approximate Fair Value Book Value Approximate Fair Value (in millions) Note receivable, noncurrent (a) $ 71 $ 71 $ 71 $ 71 Long-term debt, including current maturities (b) 6,656 6,980 6,672 6,855 ________ (a) Included within Investments in and Loans to Unconsolidated Affiliates. (b) Excludes commercial paper, unamortized items and fair value hedge carrying value adjustments.

Risk Management and Hedging A29

Risk Management and Hedging Activities Derivative Assets Offsetting (Tables)	6 Months Ended
	Jun. 30, 2017
Offsetting Derivative Assets [Abstract]
Derivative Assets Offsetting Table	Information about our interest rate swaps that had netting or rights of offset arrangements are as follows: June 30, 2017 December 31, 2016 Gross Amounts Presented in the Condensed Consolidated Balance Sheet Amounts Not Offset in the Condensed Consolidated Balance Sheet Net Amount Gross Amounts Presented in the Condensed Consolidated Balance Sheet Amounts Not Offset in the Condensed Consolidated Balance Sheet Net Amount Description (in millions) Assets $ 8 $ — $ 8 $ 9 $ — $ 9

General (Details)

General (Details)	Jun. 30, 2017
Enbridge Inc.
Business Acquisition
Ownership percentage by parent	75.00%
Publicly Owned
Business Acquisition
Ownership percentage by public	25.00%

Business Segments (Additional I

Business Segments (Additional Information) (Details)	6 Months Ended
	Jun. 30, 2017reportable_segments
Segment Reporting [Abstract]
Number of Reportable Segments	2

Business Segment Data (Details)

Business Segment Data (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Segment Reporting Information
Total operating revenues	$ 695	$ 618	$ 1,395	$ 1,242
Depreciation and amortization	87	77	172	154
Interest expense	60	56	116	112
Interest income and other		1	1	2
Earnings from continuing operations before income taxes	372	310	731	625
US Transmission
Segment Reporting Information
Total operating revenues	592	529	1,188	1,067
Earnings before interest taxes depreciation and amortization	480	406	959	817
Depreciation and amortization	79	69	156	139
Liquids
Segment Reporting Information
Total operating revenues	103	89	207	175
Earnings before interest taxes depreciation and amortization	64	58	130	114
Depreciation and amortization	8	8	16	15
Other
Segment Reporting Information
Earnings before interest taxes depreciation and amortization	(25)	(22)	(71)	(42)
Total Operating Segments
Segment Reporting Information
Total operating revenues	695	618	1,395	1,242
Earnings before interest taxes depreciation and amortization	544	464	1,089	931
Depreciation and amortization	$ 87	$ 77	$ 172	$ 154

Net Income Per Limited Partne33

Net Income Per Limited Partner Unit and Cash Distributions (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Related Party Transaction [Line Items]
Net income—controlling interests	$ 328	$ 287	$ 645	$ 585
Less: General partner’s interest in net income	94	76	183	145
Limited partners’ interest in net income attributable to common units	$ 234	$ 211	$ 462	$ 440
Weighted average limited partner units outstanding—basic and diluted	310	298	310	292
Net income per limited partner unit—basic and diluted	$ 0.75	$ 0.71	$ 1.49	$ 1.51
Partnership Interest
Related Party Transaction [Line Items]
Less: General partner’s interest in net income	$ 7	$ 6	$ 13	$ 12
General partner's interest in net income, ownership interest percentage			2.00%	2.00%
Incentive Distribution Rights
Related Party Transaction [Line Items]
Less: General partner’s interest in net income	$ 87	$ 70	$ 170	$ 133

Net Income Per Limited Partne34

Net Income Per Limited Partner Unit and Cash Distributions - Incentive Distribution Rights in Accordance with Partnership Agreement (Details)	6 Months Ended
	Jun. 30, 2017$ / shares
Minimum Quarterly Distribution
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Marginal Percentage Interest in Distributions Common Unitholders	98.00%
Marginal Percentage Interest in Distributions General Partner	2.00%
Minimum Quarterly Distribution | Minimum
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Total Quarterly Distribution Target Per-Unit Amount (in dollars per share)	$ 0.30
First Target Distribution
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Marginal Percentage Interest in Distributions Common Unitholders	98.00%
Marginal Percentage Interest in Distributions General Partner	2.00%
First Target Distribution | Maximum
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Total Quarterly Distribution Target Per-Unit Amount (in dollars per share)	$ 0.345
Second Target Distribution
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Marginal Percentage Interest in Distributions Common Unitholders	85.00%
Marginal Percentage Interest in Distributions General Partner	15.00%
Second Target Distribution | Minimum
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Total Quarterly Distribution Target Per-Unit Amount (in dollars per share)	$ 0.345
Second Target Distribution | Maximum
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Total Quarterly Distribution Target Per-Unit Amount (in dollars per share)	$ 0.375
Third Target Distribution
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Marginal Percentage Interest in Distributions Common Unitholders	75.00%
Marginal Percentage Interest in Distributions General Partner	25.00%
Third Target Distribution | Minimum
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Total Quarterly Distribution Target Per-Unit Amount (in dollars per share)	$ 0.375
Third Target Distribution | Maximum
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Total Quarterly Distribution Target Per-Unit Amount (in dollars per share)	$ 0.45
Thereafter
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Marginal Percentage Interest in Distributions Common Unitholders	50.00%
Marginal Percentage Interest in Distributions General Partner	50.00%
Thereafter | Minimum
Incentive Distribution Made to Managing Member or General Partner [Line Items]
Total Quarterly Distribution Target Per-Unit Amount (in dollars per share)	$ 0.45

Net Income Per Limited Partne35

Net Income Per Limited Partner Unit and Cash Distributions (Additional Information) (Details) - USD ($) $ / shares in Units, $ in Millions	Aug. 02, 2017	Jun. 30, 2017
Equity [Abstract]
Distribution Made To Member Or Limited Partner Distribution Period		60 days
Subsequent Event
Subsequent Event [Line Items]
Distributions to be paid to unit holders	$ 0.71375
Distribution to limited partner, declaration date	Aug. 2, 2017
Distribution made to limited partner, distribution date	Aug. 29, 2017
Distribution made to limited partner, date of record	Aug. 15, 2017
Incentive Distribution Rights | Subsequent Event
Subsequent Event [Line Items]
Contribution from Parent	$ 4

Variable Interest Entities (Det

Variable Interest Entities (Details) - USD ($) $ in Millions	Aug. 01, 2017	Apr. 01, 2016	Jun. 30, 2017	Dec. 31, 2016
Sabal Trail
Variable Interest Entity [Line Items]
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Sale of Interest by Parent		9.50%
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage			50.00%
Variable Interest Entity, Consolidated, Carrying Amount, Assets			$ 3,065	$ 2,186
Variable Interest Entity Consolidated Carrying Amount Liabilities and Equity			3,065	2,186
Sabal Trail | Current Assets
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets			95	165
Sabal Trail | Property, Plant and Equipment
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets			2,844	1,942
Sabal Trail | Regulatory Assets and Deferred Debits
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Assets			126	79
Sabal Trail | Current Liabilities
Variable Interest Entity [Line Items]
Variable Interest Entity, Consolidated, Carrying Amount, Liabilities			140	239
Sabal Trail | Equity
Variable Interest Entity [Line Items]
Variable Interest Entity Consolidated Carrying Amount Equity			$ 2,925	1,947
Nexus
Variable Interest Entity [Line Items]
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage			50.00%
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount			$ 1,000
Investments			$ 510	356
PennEast Pipeline
Variable Interest Entity [Line Items]
Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage			20.00%
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount			$ 273
Investments			$ 43	$ 11
Scenario, Forecast | Sabal Trail
Variable Interest Entity [Line Items]
Construction and Development Costs	$ 400

Intangible Asset (Details)

Intangible Asset (Details) - USD ($) $ in Millions	Apr. 01, 2016	Sep. 30, 2016	Mar. 31, 2016	Jun. 30, 2017	Jun. 30, 2016
Finite-Lived Intangible Assets [Line Items]
Purchase of intangible, net				$ 0	$ 40
Sabal Trail
Finite-Lived Intangible Assets [Line Items]
Purchase of intangible, net		$ 40	$ 48		$ 40
Consolidation, Less than Wholly Owned Subsidiary, Parent Ownership Interest, Sale of Interest by Parent	9.50%
Subsidiary or Equity Method Investee, Cumulative Percentage Ownership after All Transactions	50.00%
Intangible Assets, Reimbursement of Intangible	$ 8
Finite-Lived Intangible Assets, Gross				$ 80
Finite-Lived Intangible Asset, Useful Life				25 years

Marketable Securities and Res38

Marketable Securities and Restricted Funds - Schedule of Available-for-Sale Securities (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax	$ 0	$ 0
Investments and Other Assets - Other
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	2	10
Canadian Pipeline Abandonment Requirement | Investments and Other Assets - Other
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities	$ 2	1
Project Costs | Investments and Other Assets - Other
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities		$ 9
Available-for-sale Securities | Maximum
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, contractual maturity	1 year

Marketable Securities and Res39

Marketable Securities and Restricted Funds - Schedule of Held-to-Maturity Securities (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	$ 0	$ 0
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0	0
Current Assets - Other | Money Market Funds
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Fair Value	$ 3	$ 3
Held-to-maturity Securities | Maximum
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity securities, contractual maturity	1 year

Marketable Securities and Res40

Marketable Securities and Restricted Funds Marketable Securities and Restricted Funds - Other Restricted Funds (Details) - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Project Costs | Investments and Other Assets - Other
Gain (Loss) on Investments [Line Items]
Restricted Cash and Cash Equivalents, Noncurrent	$ 3	$ 5

Debt and Credit Facility (Addit

Debt and Credit Facility (Additional Information) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Jun. 07, 2017	Dec. 31, 2016
Line of Credit Facility [Line Items]
Expiration Date	2,021
Line of Credit Facility, Maximum Borrowing Capacity	$ 2,500
Commercial Paper Outstanding at June 30, 2017	1,324		$ 574
Available	$ 1,176
Senior Unsecured Note - Variable rate [Domain] | Spectra Energy Partners Lp [Member]
Line of Credit Facility [Line Items]
Total Facility		$ 400

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value Hierarchy Levels, Assets that are Measured at Fair Value on a Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	Jun. 30, 2017	Dec. 31, 2016
Financial Instruments [Line Items]
Assets, Fair Value Disclosure	$ 69	$ 164
Fair Value, Inputs, Level 1
Financial Instruments [Line Items]
Assets, Fair Value Disclosure	2	1
Fair Value, Inputs, Level 2
Financial Instruments [Line Items]
Assets, Fair Value Disclosure	67	163
Corporate Debt Securities | Cash and Cash Equivalents
Financial Instruments [Line Items]
Assets, Fair Value Disclosure	59	145
Corporate Debt Securities | Cash and Cash Equivalents | Fair Value, Inputs, Level 2
Financial Instruments [Line Items]
Assets, Fair Value Disclosure	59	145
Corporate Debt Securities | Investments and Other Assets - Other
Financial Instruments [Line Items]
Assets, Fair Value Disclosure		9
Corporate Debt Securities | Investments and Other Assets - Other | Fair Value, Inputs, Level 2
Financial Instruments [Line Items]
Assets, Fair Value Disclosure		9
Interest Rate Swap | Investments and Other Assets - Other
Financial Instruments [Line Items]
Assets, Fair Value Disclosure	8	9
Interest Rate Swap | Investments and Other Assets - Other | Fair Value, Inputs, Level 2
Financial Instruments [Line Items]
Assets, Fair Value Disclosure	8	9
CANADA | Canadian Equity Securities | Investments and Other Assets - Other
Financial Instruments [Line Items]
Assets, Fair Value Disclosure	2	1
CANADA | Canadian Equity Securities | Investments and Other Assets - Other | Fair Value, Inputs, Level 1
Financial Instruments [Line Items]
Assets, Fair Value Disclosure	$ 2	$ 1

Fair Value Measurements - Fai43

Fair Value Measurements - Fair Values of Financial Instruments Recorded and Carried at Book Value (Details) - USD ($) $ in Millions		Jun. 30, 2017	Dec. 31, 2016
Book Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Note receivable, noncurrent	[1]	$ 71	$ 71
Long-term debt, including current maturities	[2]	6,656	6,672
Approximate Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions
Note receivable, noncurrent	[1]	71	71
Long-term debt, including current maturities	[2]	$ 6,980	$ 6,855
[1]	Included within Investments in and Loans to Unconsolidated Affiliates.
[2]	Excludes commercial paper, unamortized items and fair value hedge carrying value adjustments.

Risk Management and Hedging A44

Risk Management and Hedging Activities (Details) - Interest Rate Swap - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Derivative [Line Items]
Gain (Loss) on Derivative Instruments, Net, Pretax	$ 0
Derivative Asset, Fair Value, Gross Asset	8	$ 9
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	0	0
Derivative Asset	$ 8	$ 9

Risk Management and Hedging A45

Risk Management and Hedging Activities - Additional Detail (Details) $ in Millions	Jun. 30, 2017USD ($)
Interest Rate Swap
Derivative [Line Items]
Derivative, Notional Amount	$ 900

Guarantees (Details)

Guarantees (Details) $ in Millions	6 Months Ended
	Jun. 30, 2017USD ($)
Guarantees [Abstract]
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 73
Guarantor Obligations, Term	2,032

Issuances of Common Units (Addi

Issuances of Common Units (Additional Information) (Detail) - USD ($) shares in Thousands, $ in Millions	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Issuances of Common Units [Line Items]
Proceeds from issuance of common units	$ 87	$ 816
Limited Partners Common
Issuances of Common Units [Line Items]
Partners units issued (in shares)	1,900
General Partner
Issuances of Common Units [Line Items]
Partners units issued (in shares)	40
Proceeds from issuance of common units	$ 2
Limited Partner and General Partner
Issuances of Common Units [Line Items]
Proceeds from issuance of common units	$ 87