Summit Midstream Partners (SMLP) 10-Q 4 Aug 17 2017 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2017	Jul. 31, 2017
Entity Information [Line Items]
Entity Registrant Name	Summit Midstream Partners, LP
Entity Central Index Key	1,549,922
Document Type	10-Q
Document Period End Date	Jun. 30, 2017
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q2
Common units
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		73,058,946
General Partner Units
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		1,490,999

UNAUDITED CONDENSED CONSOLIDATE

UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 2,588	$ 7,428
Accounts receivable	55,837	97,364
Other current assets	2,264	4,309
Total current assets	60,689	109,101
Property, plant and equipment, net	1,859,953	1,853,671
Intangible assets, net	402,020	421,452
Goodwill	16,211	16,211
Investment in equity method investees	701,020	707,415
Other noncurrent assets	14,457	7,329
Total assets	3,054,350	3,115,179
Current liabilities:
Trade accounts payable	10,327	16,251
Accrued expenses	8,278	11,389
Due to affiliate	470	258
Deferred revenue	4,745	0
Ad valorem taxes payable	7,295	10,588
Accrued interest	17,015	17,483
Accrued environmental remediation	6,183	4,301
Other current liabilities	6,305	11,471
Total current liabilities	60,618	71,741
Long-term debt	1,280,645	1,240,301
Deferred Purchase Price Obligation	579,106	563,281
Deferred revenue	13,049	57,465
Noncurrent accrued environmental remediation	2,346	5,152
Other noncurrent liabilities	7,687	7,566
Total liabilities	1,943,451	1,945,506
Commitments and contingencies (Note 15)
Common limited partner capital (73,059 units issued and outstanding at June 30, 2017 and 72,111 units issued and outstanding at December 31, 2016)	1,071,244	1,129,132
General Partner interests (1,491 units issued and outstanding at June 30, 2017 and 1,471 units issued and outstanding at December 31, 2016)	28,217	29,294
Noncontrolling interest	11,438	11,247
Total partners' capital	1,110,899	1,169,673
Total liabilities and partners' capital	$ 3,054,350	$ 3,115,179

UNAUDITED CONDENSED CONSOLIDAT3

UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - shares shares in Thousands	Jun. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Common limited partner capital (shares)	73,059	72,111
Common limited partner capital (shares)	73,059	72,111
General partner interests (shares)	1,491	1,471
General partner interests (shares)	1,491	1,471

UNAUDITED CONDENSED CONSOLIDAT4

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenues:
Gathering services and related fees	$ 84,801	$ 76,187	$ 202,814	$ 154,287
Natural gas, NGLs and condensate sales	10,595	8,581	21,715	16,169
Other revenues	6,396	4,867	13,068	9,750
Total revenues	101,792	89,635	237,597	180,206
Costs and expenses:
Cost of natural gas and NGLs	9,099	6,864	18,151	13,154
Operation and maintenance	24,016	23,410	47,708	49,252
General and administrative	12,949	12,876	27,081	25,755
Depreciation and amortization	28,688	27,963	57,257	55,691
Transaction costs	119	122	119	1,296
Loss on asset sales, net	67	74	70	11
Long-lived asset impairment	3	569	287	569
Total costs and expenses	74,941	71,878	150,673	145,728
Other income	64	19	135	41
Interest expense	(17,553)	(16,035)	(34,269)	(31,917)
Early extinguishment of debt	0	0	(22,020)	0
Deferred Purchase Price Obligation	5,058	(17,465)	(15,825)	(24,928)
Income (loss) before income taxes and loss from equity method investees	14,420	(15,724)	14,945	(22,326)
Income tax benefit (expense)	211	(360)	(241)	(283)
Loss from equity method investees	(3,385)	(34,471)	(4,041)	(31,611)
Net income (loss)	11,246	(50,555)	10,663	(54,220)
Net income attributable to Summit Investments	0	0	0	2,745
Net income (loss) attributable to noncontrolling interest	89	(268)	191	(224)
Net income (loss) attributable to SMLP	11,157	(50,287)	10,472	(56,741)
Less net income and IDRs attributable to General Partner	2,351	935	4,443	2,746
Net income (loss) attributable to limited partners	$ 8,806	$ (51,222)	$ 6,029	$ (59,487)
Earnings (loss) per limited partner unit:
Basic (USD per share)	$ 0.12	$ (0.77)	$ 0.08	$ (0.89)
Diluted (USD per share)	$ 0.12	$ (0.77)	$ 0.08	$ (0.89)
Weighted-average limited partner units outstanding:
Basic (shares)	72,532	66,587	72,341	66,540
Diluted (shares)	72,842	66,587	72,708	66,540

UNAUDITED CONDENSED CONSOLIDAT5

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF PARTNERS' CAPITAL - USD ($) $ in Thousands	Total	Class B membership interest	Noncontrolling interest	Summit Investments' equity in contributed subsidiaries	Summit Investments' equity in contributed subsidiariesClass B membership interest	Limited partners, Common	Limited partners, CommonClass B membership interest	Limited partners, Subordinated	General Partner
Beginning balance at Dec. 31, 2015	$ 1,747,299		$ 0	$ 763,057		$ 744,977		$ 213,631	$ 25,634
Increase (Decrease) in Partners' Capital [Roll Forward]
Net (loss) income	(54,220)		(224)	2,745		(60,527)		1,040	2,746
Distributions to unitholders	(82,020)					(62,475)		(14,034)	(5,511)
Unit-based compensation	3,665	$ 285			$ 130	3,665	$ 155
Tax withholdings on vested SMLP LTIP awards	(796)					(796)
Subordinated units conversion						200,637		(200,637)
Purchase of 2016 Drop Down Assets	(866,858)			(866,858)
Establishment of noncontrolling interest			11,261	(11,261)
Distribution of debt related to Carve-Out Financial Statements of Summit Investments	342,926			342,926
Excess of acquired carrying value over consideration paid for Polar and Divide	247,997			(247,997)		243,044			4,953
Cash advance from Summit Investments to contributed subsidiaries, net	12,214			12,214
Expenses paid by Summit Investments on behalf of contributed subsidiaries	4,821			4,821
Capitalized interest allocated to contributed subsidiaries from Summit Investments	223			223
Ending balance at Jun. 30, 2016	1,107,539		11,037	$ 0		1,068,680		$ 0	27,822
Beginning balance at Dec. 31, 2016	1,169,673		11,247			1,129,132			29,294
Increase (Decrease) in Partners' Capital [Roll Forward]
Net (loss) income	10,663		191			6,029			4,443
Distributions to unitholders	(89,029)					(83,044)			(5,985)
Unit-based compensation	3,919					3,919
Tax withholdings on vested SMLP LTIP awards	(2,051)					(2,051)
Distribution of debt related to Carve-Out Financial Statements of Summit Investments	0
Excess of acquired carrying value over consideration paid for Polar and Divide	0
Capitalized interest allocated to contributed subsidiaries from Summit Investments	0
ATM Program issuances, net of costs	17,259					17,259
Contribution from General Partner	465								465
Ending balance at Jun. 30, 2017	$ 1,110,899		$ 11,438			$ 1,071,244			$ 28,217

UNAUDITED CONDENSED CONSOLIDAT6

UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows from operating activities:
Net income (loss)	$ 10,663	$ (54,220)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	56,955	55,957
Amortization of debt issuance costs	2,072	1,947
Deferred Purchase Price Obligation	15,825	24,928
Unit-based and noncash compensation	3,999	3,950
Loss from equity method investees	4,041	31,611
Distributions from equity method investees	18,003	24,181
Loss on asset sales, net	70	11
Long-lived asset impairment	287	569
Early extinguishment of debt	22,020	0
Write-off of debt issuance costs	302	0
Changes in operating assets and liabilities:
Accounts receivable	41,527	41,276
Trade accounts payable	(4,372)	1,447
Accrued expenses	(3,111)	1,008
Due from (to) affiliate	212	(966)
Deferred revenue	(39,671)	2,033
Ad valorem taxes payable	(3,293)	(2,613)
Accrued interest	(468)	0
Accrued environmental remediation, net	(924)	(1,752)
Other, net	(2,796)	2,133
Net cash provided by operating activities	121,341	131,500
Cash flows from investing activities:
Capital expenditures	(45,912)	(91,372)
Contributions to equity method investees	(15,649)	(15,645)
Acquisitions of gathering systems from affiliate	0	(359,431)
Other, net	(521)	(435)
Net cash used in investing activities	(62,082)	(466,883)
Cash flows from financing activities:
Distributions to unitholders	(89,029)	(82,020)
Borrowings under Revolving Credit Facility	112,500	439,300
Repayments under Revolving Credit Facility	(269,500)	(50,300)
Debt issuance costs	(15,613)	(2,766)
Payment of redemption and call premiums on senior notes	(17,913)	0
Proceeds from ATM Program issuances, net of costs	17,259	0
Contribution from General Partner	465	0
Cash advance from Summit Investments to contributed subsidiaries, net	0	12,214
Expenses paid by Summit Investments on behalf of contributed subsidiaries	0	4,821
Issuance of senior notes	500,000	0
Tender and redemption of senior notes	(300,000)	0
Other, net	(2,268)	(916)
Net cash (used in) provided by financing activities	(64,099)	320,333
Net change in cash and cash equivalents	(4,840)	(15,050)
Cash and cash equivalents, beginning of period	7,428	21,793
Cash and cash equivalents, end of period	2,588	6,743
Supplemental cash flow disclosures:
Cash interest paid	33,382	31,464
Less capitalized interest	918	1,779
Interest paid (net of capitalized interest)	32,464	29,685
Noncash investing and financing activities:
Capital expenditures in trade accounts payable (period-end accruals)	6,869	14,322
Issuance of Deferred Purchase Price Obligation to affiliate to partially fund the 2016 Drop Down	0	507,427
Excess of acquired carrying value over consideration paid and recognized for 2016 Drop Down Assets	0	247,997
Distribution of debt related to Carve-Out Financial Statements of Summit Investments	0	342,926
Capitalized interest allocated to contributed subsidiaries from Summit Investments	$ 0	$ 223

ORGANIZATION, BUSINESS OPERATIO

ORGANIZATION, BUSINESS OPERATIONS AND PRESENTATION AND CONSOLIDATION	6 Months Ended
	Jun. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
ORGANIZATION, BUSINESS OPERATIONS AND PRESENTATION AND CONSOLIDATION	ORGANIZATION, BUSINESS OPERATIONS AND PRESENTATION AND CONSOLIDATION Organization. SMLP, a Delaware limited partnership, was formed in May 2012 and began operations in October 2012 in connection with its IPO of common limited partner units. SMLP is a growth-oriented limited partnership focused on developing, owning and operating midstream energy infrastructure assets that are strategically located in the core producing areas of unconventional resource basins, primarily shale formations, in the continental United States. Our business activities are conducted through various operating subsidiaries, each of which is owned or controlled by our wholly owned subsidiary holding company, Summit Holdings, a Delaware limited liability company. References to the "Partnership," "we," or "our" refer collectively to SMLP and its subsidiaries. The General Partner, a Delaware limited liability company, manages our operations and activities. Summit Investments, a Delaware limited liability company, is the ultimate owner of our General Partner and has the right to appoint the entire Board of Directors. Summit Investments is controlled by Energy Capital Partners. As of June 30, 2017, a subsidiary of Energy Capital Partners directly owned 5,915,827 SMLP common units. In addition to its approximate 2% general partner interest in SMLP (including the IDRs in respect of SMLP), Summit Investments has indirect ownership interests in our common units. As of June 30, 2017 , Summit Investments beneficially owned 25,854,581 SMLP common units. Neither SMLP nor its subsidiaries have any employees. All of the personnel that conduct our business are employed by Summit Investments, but these individuals are sometimes referred to as our employees. Business Operations. We provide natural gas gathering, treating and processing services as well as crude oil and produced water gathering services pursuant to primarily long-term and fee-based agreements with our customers. Our results are driven primarily by the volumes of natural gas that we gather, treat, compress and process as well as by the volumes of crude oil and produced water that we gather. We are the owner-operator of or have significant ownership interests in the following gathering systems: • Ohio Gathering, a natural gas gathering system and a condensate stabilization facility operating in the Appalachian Basin, which includes the Utica and Point Pleasant shale formations in southeastern Ohio; • Summit Utica, a natural gas gathering system operating in the Appalachian Basin, which includes the Utica and Point Pleasant shale formations in southeastern Ohio; • Bison Midstream, an associated natural gas gathering system operating in the Williston Basin, which includes the Bakken and Three Forks shale formations in northwestern North Dakota; • Polar and Divide, crude oil and produced water gathering systems and transmission pipelines located in the Williston Basin, which includes the Bakken and Three Forks shale formations in northwestern North Dakota; • Tioga Midstream, crude oil, produced water and associated natural gas gathering systems operating in the Williston Basin, which includes the Bakken and Three Forks shale formations in northwestern North Dakota; • Grand River, a natural gas gathering and processing system located in the Piceance Basin, which includes the Mesaverde formation and the Mancos and Niobrara shale formations in western Colorado and eastern Utah; • Niobrara G&P, an associated natural gas gathering and processing system operating in the DJ Basin, which includes the Niobrara and Codell shale formations in northeastern Colorado; • DFW Midstream, a natural gas gathering system operating in the Fort Worth Basin, which includes the Barnett Shale formation in north-central Texas; • Mountaineer Midstream, a natural gas gathering system operating in the Appalachian Basin, which includes the Marcellus Shale formation in northern West Virginia; and • Summit Permian, an associated natural gas gathering and processing system under development in the northern Delaware Basin in southeastern New Mexico. In February 2016, the Partnership and SMP Holdings, a wholly owned subsidiary of Summit Investments, entered into a contribution agreement (the "Contribution Agreement") pursuant to which SMP Holdings agreed to contribute to the Partnership substantially all of its limited partner interest in OpCo, a Delaware limited partnership that owns (i) 100% of the issued and outstanding membership interests of Summit Utica, Meadowlark Midstream and Tioga Midstream and collectively with Summit Utica and Meadowlark Midstream, (the "Contributed Entities"), each a limited liability company and (ii) a 40% ownership interest in each of OGC and OCC (collectively with OpCo and the Contributed Entities, the “2016 Drop Down Assets”)(the “2016 Drop Down”). The 2016 Drop Down closed in March 2016; concurrent therewith, a subsidiary of Summit Investments retained a 1% noncontrolling interest in OpCo. Summit Marketing (formerly known as Summit Midstream OpCo GP, LLC), a Delaware limited liability company and a wholly owned subsidiary of Summit Holdings, manages OpCo, a Delaware limited liability partnership, and provides natural gas and crude oil marketing services in and around our gathering systems. Presentation and Consolidation. We prepare our unaudited condensed consolidated financial statements in accordance with GAAP as established by the FASB. We make estimates and assumptions that affect the reported amounts of assets and liabilities at the balance sheet dates, including fair value measurements, the reported amounts of revenue and expense and the disclosure of contingencies. Although management believes these estimates are reasonable, actual results could differ from its estimates. The unaudited condensed consolidated financial statements include the assets, liabilities and results of operations of SMLP and its subsidiaries. All intercompany transactions among the consolidated entities have been eliminated in consolidation. Comprehensive income or loss is the same as net income or loss for all periods presented. The financial position, results of operations and cash flows of acquired drop down assets, liabilities, expenses or entities that were carved out of entities held by Summit Investments and included herein have been derived from the accounting records of the respective Summit Investments' subsidiary on a carve-out basis. SMLP recognized its drop down acquisitions at Summit Investments' historical cost because the acquisitions were executed by entities under common control. The excess of Summit Investments' net investment over the consideration paid and recognized for a contributed subsidiary is recognized as an addition to partners' capital, while the excess of purchase price paid and recognized over net investment is recognized as a reduction to partners' capital. Due to the common control aspect, we account for drop down transactions on an “as-if pooled” basis for the periods during which common control existed. These unaudited condensed consolidated financial statements have been prepared pursuant to the rules and the regulations of the SEC. Certain information and note disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to those rules and regulations. We believe that the disclosures made are adequate to make the information not misleading. In the opinion of management, the unaudited condensed consolidated financial statements contain all adjustments, including normal recurring adjustments, which are necessary to fairly present the unaudited condensed consolidated balance sheet as of June 30, 2017, the unaudited condensed consolidated statements of operations for the three- and six- month periods ended June 30, 2017 and 2016 and the unaudited condensed consolidated statements of partners' capital and cash flows for the six-month periods ended June 30, 2017 and 2016. The balance sheet at December 31, 2016 included herein was derived from our audited financial statements, but does not include all disclosures required by GAAP. These unaudited condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto that are included in our annual report on Form 10-K for the year ended December 31, 2016, as filed with the SEC on February 27, 2017 (the "2016 Annual Report"). The results of operations for an interim period are not necessarily indicative of results expected for a full year.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	6 Months Ended
	Jun. 30, 2017
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES There have been no changes to our significant accounting policies since December 31, 2016. Recent Accounting Pronouncements. Accounting standard setters frequently issue new or revised accounting rules. We review new pronouncements to determine the impact, if any, on our financial statements. Accounting standards that have or could possibly have a material effect on our financial statements are discussed below. Recently Adopted Accounting Pronouncements . We have recently adopted the following accounting pronouncements: • ASU No. 2016-09 Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting ("ASU 2016-09"). ASU 2016-09 simplifies several aspects for share-based payment award transactions, including income tax consequences, the liability or equity classification of awards and classification on the statements of cash flows. ASU 2016-09 is effective for public companies for fiscal years beginning after December 15, 2016. It does not specify a single transition approach, rather it specifies retrospective, modified retrospective and/or prospective transition approaches based on the aspect being applied. We adopted the provisions of ASU 2016-09 effective January 1, 2017. The adoption of this standard had no impact on our consolidated financial statements. Accounting Pronouncements Pending Adoption . We are currently in the process of evaluating the applicability and/or impact of the following accounting pronouncements: • ASU No. 2014-09 Revenue from Contracts with Customers (Topic 606) ("ASU 2014-09"). Under ASU 2014-09, revenue will be recognized under a five-step model: (i) identify the contract with the customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to performance obligations; and (v) recognize revenue when (or as) the performance obligation is satisfied. ASU 2014-09 is effective for fiscal years and interim periods within those years, beginning after December 15, 2017 and allows for early adoption. We expect to adopt the provisions of ASU 2014-09 effective January 1, 2018 using the modified retrospective method. We have substantially completed our review of our existing contracts under the new guidance. However, we are still assessing the financial statement impact of adoption for certain items discussed below. For contracts where we perform gathering services and earn a per-unit fee which is recognized at a point in time, revenue will be recognized over time as the service is performed, which is expected to accelerate the recognition of revenue by an immaterial amount. In addition, our contracts generally contain forms of what will be considered variable consideration, which will likely be constrained as the volumes are susceptible to factors outside of our control and influence. However, we will be billing amounts that correspond directly to the value transferred such that the resulting revenue recognized will be similar to current GAAP. We are continuing to evaluate our MVCs and contributions in aid of construction and cannot currently fully conclude on the impact of adoption. We are working with an industry group to develop our position on certain implementation matters. We anticipate that we will be able to complete our assessment of the impact of adoption by the end of the third quarter of 2017. • ASU No. 2016-02 Leases (Topic 842) ("ASU 2016-02"). ASU 2016-02 requires that lessees recognize all leases on the balance sheet, with the exception of short-term leases. A lease liability will be recorded for the obligation of a lessee to make lease payments arising from a lease. A right-of-use asset will be recorded which represents the lessee’s right to use, or to control the use of, a specified asset for a lease term. We are currently evaluating the impact of this guidance on lessor accounting but have made no determinations at this time. ASU 2016-02 is effective for public companies for fiscal years beginning after December 15, 2018, and requires the modified retrospective approach for transition. We are currently evaluating the provisions of ASU 2016-02 to determine its impact on our financial statements and related disclosures and expect to adopt its provisions effective January 1, 2019. • ASU No. 2016-08 Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net) ("ASU 2016-08"). ASU 2016-08 does not change the core principle of Topic 606, rather it clarifies the implementation guidance on principal versus agent considerations. We expect to adopt the provisions of ASU 2016-08 effective January 1, 2018. Our position regarding the impact of and transition method for this update is the same as for ASU 2014-09. • ASU No. 2016-10 Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing ("ASU 2016-10"). ASU 2016-10 clarifies the following two aspects of Topic 606: (i) identifying performance obligations; and (ii) the licensing implementation guidance, while retaining the related principles for those areas. We expect to adopt the provisions of ASU 2016-10 effective January 1, 2018. Our position regarding the impact of and transition method for this update is the same as for ASU 2014-09. • ASU No. 2016-12 Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients ("ASU 2016-12"). ASU 2016-12 does not change the core principle of the guidance in Topic 606. Rather, the amendments therein affect only the narrow aspects of Topic 606 including assessing the collectability criterion and issues related to contract modification at transition and completed contracts at transition. We expect to adopt the provisions of ASU 2016-12 effective January 1, 2018. Our position regarding the impact of and transition method for this update is the same as for ASU 2014-09.

PROPERTY, PLANT AND EQUIPMENT,

PROPERTY, PLANT AND EQUIPMENT, NET	6 Months Ended
	Jun. 30, 2017
Property, Plant and Equipment [Abstract]
PROPERTY, PLANT AND EQUIPMENT, NET	PROPERTY, PLANT AND EQUIPMENT, NET Details on property, plant and equipment follow. June 30, 2017 December 31, 2016 (In thousands) Gathering and processing systems and related equipment $ 2,067,428 $ 2,026,363 Construction in progress 40,332 39,954 Land and line fill 11,735 11,442 Other 35,083 35,227 Total 2,154,578 2,112,986 Less accumulated depreciation 294,625 259,315 Property, plant and equipment, net $ 1,859,953 $ 1,853,671 Depreciation expense and capitalized interest follow. Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) Depreciation expense $ 18,607 $ 17,595 $ 37,098 $ 34,966 Capitalized interest 450 1,063 918 1,779

SEGMENT INFORMATION

SEGMENT INFORMATION	6 Months Ended
	Jun. 30, 2017
Segment Reporting [Abstract]
SEGMENT INFORMATION	SEGMENT INFORMATION We evaluate our business operations each reporting period to determine whether any of our gathering system operating segments in which we internally report financial information are considered significant and would require us to separately disclose certain segment financial information in our external reporting. As a result of our evaluation for the three-months ended June 30, 2017, we determined that both the Summit Utica natural gas gathering system and the Ohio Gathering natural gas gathering system, each previously reported within the Utica Shale reportable segment, were and are expected to continue to be significant operating segments. As such, we are modifying our current segments such that the Utica Shale reportable segment includes the Summit Utica gathering system and the Ohio Gathering reportable segment includes our ownership interest in OGC and OCC. For the three- and six-months ended June 30, 2017, we have disclosed the required segment information for Summit Utica and Ohio Gathering and the periods prior to January 1, 2017 have been recast to reflect this change. As of June 30, 2017, our reportable segments are: • the Utica Shale, which is served by Summit Utica; • Ohio Gathering, which includes our ownership interest in OGC and OCC; • the Williston Basin, which is served by Bison Midstream, Polar and Divide and Tioga Midstream; • the Piceance/DJ Basins, which is served by Grand River and Niobrara G&P; • the Barnett Shale, which is served by DFW Midstream; and • the Marcellus Shale, which is served by Mountaineer Midstream. Each of our reportable segments provides midstream services in a specific geographic area. Our reportable segments reflect the way in which we internally report the financial information used to make decisions and allocate resources in connection with our operations. As noted above, the Ohio Gathering reportable segment includes our investment in Ohio Gathering (see Note 7). Income or loss from equity method investees, as reflected on the statements of operations, solely relates to Ohio Gathering and is recognized and disclosed on a one-month lag (see Note 7). No other line items in the statements of operations or cash flows, as disclosed in the tables below, include results for our investment in Ohio Gathering. Corporate and other represents those results that are: (i) not specifically attributable to a reportable segment; (ii) not individually reportable; or (iii) that have not been allocated to our reportable segments, including certain general and administrative expense items, natural gas and crude oil marketing services and transaction costs for the purpose of evaluating their performance. Assets by reportable segment follow. June 30, 2017 December 31, 2016 (In thousands) Assets: Utica Shale $ 213,030 $ 199,392 Ohio Gathering 701,020 707,415 Williston Basin 699,361 724,084 Piceance/DJ Basins 799,058 843,440 Barnett Shale 395,266 404,314 Marcellus Shale 220,899 224,709 Total reportable segment assets 3,028,634 3,103,354 Corporate and other 25,940 12,294 Eliminations (224 ) (469 ) Total assets $ 3,054,350 $ 3,115,179 Revenues by reportable segment follow. Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) Revenues (1): Utica Shale $ 10,456 $ 5,403 $ 19,252 $ 9,686 Williston Basin 29,114 27,507 95,999 57,517 Piceance/DJ Basins 33,763 29,411 68,571 58,402 Barnett Shale 20,904 20,856 38,646 41,257 Marcellus Shale 7,365 6,458 14,269 13,344 Total reportable segments revenue 101,602 89,635 236,737 180,206 Corporate and other 1,362 — 3,148 — Eliminations (1,172 ) — (2,288 ) — Total revenues $ 101,792 $ 89,635 $ 237,597 $ 180,206 __________ (1) Excludes revenues earned by Ohio Gathering due to equity method accounting. Counterparties accounting for more than 10% of total revenues were as follows: Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 Percentage of total revenues (1)(2): Counterparty A - Piceance Basin 10 % * * * Counterparty B - Barnett Shale 11 % * * * Counterparty C - Utica Shale 10 % * * * Counterparty D - Williston Basin * * 21 % * __________ (1) Includes recognition of revenue that was previously deferred in connection with minimum volume commitments (see Note 8). (2) Excludes revenues earned by Ohio Gathering due to equity method accounting. * Less than 10% Depreciation and amortization, including the amortization expense associated with our favorable and unfavorable gas gathering contracts as reported in other revenues, by reportable segment follows. Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) Depreciation and amortization (1): Utica Shale $ 1,748 $ 952 $ 3,395 $ 1,796 Williston Basin 8,385 8,410 16,766 16,767 Piceance/DJ Basins 12,225 12,297 24,436 24,570 Barnett Shale (2) 3,762 4,057 7,524 8,113 Marcellus Shale 2,263 2,222 4,526 4,441 Total reportable segment depreciation and amortization 28,383 27,938 56,647 55,687 Corporate and other 154 154 308 270 Total depreciation and amortization $ 28,537 $ 28,092 $ 56,955 $ 55,957 __________ (1) Excludes depreciation and amortization recognized by Ohio Gathering due to equity method accounting. (2) Includes the amortization expense associated with our favorable and unfavorable gas gathering contracts as reported in other revenues. Cash paid for capital expenditures by reportable segment follow. Six months ended June 30, 2017 2016 (In thousands) Cash paid for capital expenditures (1): Utica Shale $ 16,473 $ 54,064 Williston Basin 11,085 21,919 Piceance/DJ Basins 11,934 10,633 Barnett Shale (399 ) 2,109 Marcellus Shale 407 2,135 Total reportable segment capital expenditures 39,500 90,860 Corporate and other 6,412 512 Total cash paid for capital expenditures $ 45,912 $ 91,372 __________ (1) Excludes cash paid for capital expenditures by Ohio Gathering due to equity method accounting. During the six months ended June 30, 2017, Corporate and other primarily includes cash paid for capital expenditures of approximately $5.0 million for Summit Permian. We assess the performance of our reportable segments based on segment adjusted EBITDA. We define segment adjusted EBITDA as total revenues less total costs and expenses; plus (i) other income excluding interest income, (ii) our proportional adjusted EBITDA for equity method investees, (iii) depreciation and amortization, (iv) adjustments related to MVC shortfall payments, (v) unit-based and noncash compensation, (vi) change in the Deferred Purchase Price Obligation fair value, (vii) early extinguishment of debt expense, (viii) impairments and (ix) other noncash expenses or losses, less other noncash income or gains. We define proportional adjusted EBITDA for our equity method investees as the product of (i) total revenues less total expenses, excluding impairments and other noncash income or expense items and (ii) amortization for deferred contract costs; multiplied by our ownership interest in Ohio Gathering during the respective period. For the purpose of evaluating segment performance, we exclude the effect of Corporate and other revenues and expenses, such as certain general and administrative expenses (including compensation-related expenses and professional services fees), natural gas and crude oil marketing services, transaction costs, interest expense, change in the Deferred Purchase Price Obligation fair value, early extinguishment of debt expense and income tax expense or benefit from segment adjusted EBITDA. Segment adjusted EBITDA by reportable segment follows. Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) Reportable segment adjusted EBITDA: Utica Shale $ 9,533 $ 4,727 $ 17,445 $ 7,916 Ohio Gathering 9,606 12,725 18,679 25,113 Williston Basin 17,155 19,209 34,964 38,929 Piceance/DJ Basins 27,274 26,231 56,248 51,046 Barnett Shale 12,998 13,913 25,086 27,990 Marcellus Shale 5,446 4,807 11,093 9,408 Total of reportable segments’ measures of profit or loss $ 82,012 $ 81,612 $ 163,515 $ 160,402 A reconciliation of income or loss before income taxes and loss from equity method investees to total of reportable segments' measures of profit or loss follows. Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) Reconciliation of income (loss) before income taxes and loss from equity method investees to total of reportable segments' measures of profit or loss: Income (loss) before income taxes and loss from equity method investees $ 14,420 $ (15,724 ) $ 14,945 $ (22,326 ) Add: Corporate and other 9,435 9,247 19,528 18,006 Interest expense 17,553 16,035 34,269 31,917 Early extinguishment of debt — — 22,020 — Deferred Purchase Price Obligation (5,058 ) 17,465 15,825 24,928 Depreciation and amortization 28,537 28,092 56,955 55,957 Proportional adjusted EBITDA for equity method investees 9,606 12,725 18,679 25,113 Adjustments related to MVC shortfall payments 5,578 11,135 (23,062 ) 22,277 Unit-based and noncash compensation 1,871 1,994 3,999 3,950 Loss on asset sales, net 67 74 70 11 Long-lived asset impairment 3 569 287 569 Total of reportable segments' measures of profit or loss $ 82,012 $ 81,612 $ 163,515 $ 160,402 We include adjustments related to MVC shortfall payments in our calculation of segment adjusted EBITDA to account for (i) the net increases or decreases in deferred revenue for MVC shortfall payments and (ii) our inclusion of expected annual MVC shortfall payments. With respect to the impact of a net change in deferred revenue for MVC shortfall payments, we treat increases in deferred revenue balances as a favorable adjustment to segment adjusted EBITDA, while decreases in deferred revenue balances are treated as an unfavorable adjustment to segment adjusted EBITDA. We also include a proportional amount of any historical and expected MVC shortfall payments in each quarter prior to the quarter in which we actually recognize the shortfall payment. The expected MVC shortfall payment adjustments have not been billed to our customers and are not recognized in our unaudited condensed consolidated financial statements. Adjustments related to MVC shortfall payments by reportable segment follow. Three months ended June 30, 2017 Williston Basin Piceance/DJ Basins Barnett Shale Total (In thousands) Adjustments related to MVC shortfall payments: Net change in deferred revenue for MVC shortfall payments $ — $ (1,186 ) $ — $ (1,186 ) Expected MVC shortfall payments 1,982 6,522 (1,740 ) 6,764 Total adjustments related to MVC shortfall payments $ 1,982 $ 5,336 $ (1,740 ) $ 5,578 Three months ended June 30, 2016 Williston Basin Piceance/DJ Basins Barnett Shale Total (In thousands) Adjustments related to MVC shortfall payments: Net change in deferred revenue for MVC shortfall payments $ — $ 1,237 $ (677 ) $ 560 Expected MVC shortfall payments 4,261 6,219 95 10,575 Total adjustments related to MVC shortfall payments $ 4,261 $ 7,456 $ (582 ) $ 11,135 Six months ended June 30, 2017 Williston Basin Piceance/DJ Basins Barnett Shale Total (In thousands) Adjustments related to MVC shortfall payments: Net change in deferred revenue for MVC shortfall payments $ (37,693 ) $ (1,978 ) $ — $ (39,671 ) Expected MVC shortfall payments 3,964 13,067 (422 ) 16,609 Total adjustments related to MVC shortfall payments $ (33,729 ) $ 11,089 $ (422 ) $ (23,062 ) Six months ended June 30, 2016 Williston Basin Piceance/DJ Basins Barnett Shale Total (In thousands) Adjustments related to MVC shortfall payments: Net change in deferred revenue for MVC shortfall payments $ 235 $ 2,475 $ (677 ) $ 2,033 Expected MVC shortfall payments 7,562 12,498 184 20,244 Total adjustments related to MVC shortfall payments $ 7,797 $ 14,973 $ (493 ) $ 22,277

AMORTIZING INTANGIBLE ASSETS AN

AMORTIZING INTANGIBLE ASSETS AND UNFAVORABLE GAS GATHERING CONTRACT	6 Months Ended
	Jun. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
AMORTIZING INTANGIBLE ASSETS AND UNFAVORABLE GAS GATHERING CONTRACT	AMORTIZING INTANGIBLE ASSETS AND UNFAVORABLE GAS GATHERING CONTRACT Details regarding our intangible assets and the unfavorable gas gathering contract (included in other noncurrent liabilities), all of which are subject to amortization, follow. June 30, 2017 Useful lives (In years) Gross carrying amount Accumulated amortization Net (Dollars in thousands) Favorable gas gathering contracts 18.7 $ 24,195 $ (11,572 ) $ 12,623 Contract intangibles 12.5 426,464 (163,570 ) 262,894 Rights-of-way 26.1 154,519 (28,016 ) 126,503 Total intangible assets $ 605,178 $ (203,158 ) $ 402,020 Unfavorable gas gathering contract 10.0 $ 10,962 $ (7,995 ) $ 2,967 December 31, 2016 Useful lives (In years) Gross carrying amount Accumulated amortization Net (Dollars in thousands) Favorable gas gathering contracts 18.7 $ 24,195 $ (10,795 ) $ 13,400 Contract intangibles 12.5 426,464 (146,468 ) 279,996 Rights-of-way 26.1 153,015 (24,959 ) 128,056 Total intangible assets $ 603,674 $ (182,222 ) $ 421,452 Unfavorable gas gathering contract 10.0 $ 10,962 $ (6,916 ) $ 4,046 We recognized amortization expense in other revenues as follows: Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) Amortization expense – favorable gas gathering contracts $ (388 ) $ (317 ) $ (777 ) $ (655 ) Amortization expense – unfavorable gas gathering contract 539 188 1,079 389 We recognized amortization expense in costs and expenses as follows: Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) Amortization expense – contract intangibles $ 8,551 $ 8,854 $ 17,102 $ 17,708 Amortization expense – rights-of-way 1,530 1,514 3,057 3,017 The estimated aggregate annual amortization expected to be recognized for the remainder of 2017 and each of the four succeeding fiscal years follows. Intangible assets Unfavorable gas gathering contract (In thousands) 2017 $ 21,196 $ 1,079 2018 41,373 1,888 2019 41,204 — 2020 43,453 — 2021 41,679 —

GOODWILL

GOODWILL	6 Months Ended
	Jun. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
GOODWILL	GOODWILL We evaluate goodwill for impairment annually on September 30 and whenever events or circumstances indicate that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. There have been no impairments of goodwill during the three- and six-months ended June 30, 2017. Fair Value Measurement. Our impairment determinations, in the context of (i) our annual impairment evaluations and (ii) our other-than-annual impairment evaluations involved significant assumptions and judgments, as discussed in the 2016 Annual Report. Differing assumptions regarding any of these inputs could have a significant effect on the various valuations. As such, the fair value measurements utilized within these models are classified as non-recurring Level 3 measurements in the fair value hierarchy because they are not observable from objective sources. Due to the volatility of the inputs used, we cannot predict the likelihood of any future impairment.

EQUITY METHOD INVESTMENTS

EQUITY METHOD INVESTMENTS	6 Months Ended
	Jun. 30, 2017
Equity Method Investments and Joint Ventures [Abstract]
EQUITY METHOD INVESTMENTS	EQUITY METHOD INVESTMENTS Ohio Gathering owns, operates and is currently developing midstream infrastructure consisting of a liquids-rich natural gas gathering system, a dry natural gas gathering system and a condensate stabilization facility in the Utica Shale in southeastern Ohio. Ohio Gathering provides gathering services pursuant to primarily long-term, fee-based gathering agreements, which include acreage dedications. In June 2017 and June 2016, an impairment loss was recognized by Ohio Gathering. Although we recognize activity for Ohio Gathering on a one-month lag, we recorded the impairment loss in our results of operations for the second quarter of 2017 and 2016 because the information was available to us. We recorded our 40% share of the impairment loss, or $3.5 million in June 2017 and $37.8 million in June 2016, in loss from equity method investees in the unaudited condensed consolidated statements of operations. A reconciliation of our 40% ownership interest in Ohio Gathering to our investment per Ohio Gathering's books and records follows (in thousands). Investment in equity method investees, June 30, 2017 $ 701,020 June cash distribution 3,128 June cash contribution (3,484 ) Impairment loss 3,474 Basis difference (136,860 ) Investment in equity method investees, net of basis difference, May 31, 2017 $ 567,278 Summarized statements of operations information for OGC and OCC follows (amounts represent 100% of investee financial information). Results include asset impairments of $8.7 million for the three- and six-month periods ending June 30, 2017 and $94.4 million for the three- and six-month periods ending June 30, 2016. Three months ended May 31, 2017 Three months ended May 31, 2016 OGC OCC OGC OCC (In thousands) Total revenues $ 31,083 $ 2,004 $ 38,444 $ 5,417 Total operating expenses 33,221 1,836 22,572 98,748 Net (loss) income (139 ) 23 15,868 (93,701 ) Six months ended May 31, 2017 Six months ended May 31, 2016 OGC OCC OGC OCC (In thousands) Total revenues $ 68,158 $ 4,057 $ 76,243 $ 10,615 Total operating expenses 60,326 4,309 45,105 103,307 Net income (loss) 7,834 (1,192 ) 31,137 (93,245 )

DEFERRED REVENUE

DEFERRED REVENUE	6 Months Ended
	Jun. 30, 2017
Deferred Revenue Disclosure [Abstract]
Deferred Revenue	DEFERRED REVENUE A rollforward of current deferred revenue follows. Williston Basin Piceance/DJ Basins Total current (In thousands) Current deferred revenue, January 1, 2017 $ — $ — $ — Additions — 12,602 12,602 Less revenue recognized — 7,857 7,857 Current deferred revenue, June 30, 2017 $ — $ 4,745 $ 4,745 A rollforward of noncurrent deferred revenue follows. Williston Basin Piceance/DJ Basins Total noncurrent (In thousands) Noncurrent deferred revenue, January 1, 2017 $ 37,693 $ 19,772 $ 57,465 Less revenue recognized 37,693 1,978 39,671 Less reclassification to current deferred revenue — 4,745 4,745 Noncurrent deferred revenue, June 30, 2017 $ — $ 13,049 $ 13,049 As of June 30, 2017 , accounts receivable included $7.6 million of total shortfall payment billings, of which none related to MVC arrangements that can be utilized to offset gathering fees in subsequent periods. During the first quarter of 2017, we amended an agreement with one of our key customers in the Williston Basin segment. As a result, we recognized previously deferred revenue of $37.7 million as gathering services and related fees during the first quarter of 2017.

DEBT

DEBT	6 Months Ended
	Jun. 30, 2017
Debt Disclosure [Abstract]
DEBT	DEBT Debt consisted of the following: June 30, 2017 December 31, 2016 (In thousands) Summit Holdings variable rate senior secured Revolving Credit Facility (3.73% at June 30, 2017 and 3.27% at December 31, 2016) due May 2022 $ 491,000 $ 648,000 Summit Holdings 5.5% senior unsecured notes due August 2022 300,000 300,000 Less unamortized debt issuance costs (1) (3,180 ) (3,516 ) Summit Holdings 5.75% senior unsecured notes due April 2025 500,000 — Less unamortized debt issuance costs (1) (7,175 ) — Summit Holdings 7.5% senior unsecured notes redeemed March 2017 (2) — 300,000 Less unamortized debt issuance costs (1) (2) — (4,183 ) Total long-term debt $ 1,280,645 $ 1,240,301 __________ (1) Issuance costs are being amortized over the life of the notes. (2) Debt was extinguished following the 5.75% Senior Notes offering in February 2017. In conjunction with the early debt extinguishment, the remaining unamortized debt issuance costs were written off. The aggregate amount of debt maturing to be recognized for the remainder of 2017 and each of the four succeeding fiscal years follow (in thousands): 2017 $ — 2018 — 2019 — 2020 — 2021 — Thereafter 1,291,000 Total long-term debt $ 1,291,000 Revolving Credit Facility. Summit Holdings has a senior secured revolving credit facility that allows for revolving loans, letters of credit and swingline loans. On May 26, 2017, Summit Holdings amended and restated its revolving credit facility with a third amended and restated credit agreement which: (i) maintained the revolving credit facility commitments of $1.25 billion , (ii) extended the maturity from November 2018 to May 2022, (iii) includes a $250.0 million accordion feature, (iv) maintained the same leverage-based pricing and commitment fee grid, (v) increased the maximum permitted total leverage ratio, as defined in the credit agreement, from 5.00 to 1.00 to 5.50 to 1.00 and (vi) includes a maximum permitted senior secured leverage ratio, as defined in the credit agreement, of 3.75 to 1.00. Borrowings under the revolving credit facility bear interest, at the election of Summit Holdings, at a rate based on the alternate base rate (as defined in the credit agreement) plus an applicable margin ranging from 0.75% to 1.75% or the adjusted Eurodollar rate (as defined in the credit agreement) plus an applicable margin ranging from 1.75% to 2.75% , with the commitment fee ranging from 0.30% to 0.50% in each case based on our relative leverage at the time of determination. At June 30, 2017, the applicable margin under LIBOR borrowings was 2.50% , the interest rate was 3.73% and the unused portion of the Revolving Credit Facility totaled $759.0 million (subject to a commitment fee of 0.50% ). The revolving credit facility is secured by the membership interests of Summit Holdings and the membership interests of all the subsidiaries of Summit Holdings and by substantially all of the assets of Summit Holdings and its subsidiaries (subject to exclusions set forth in the credit agreement). It is guaranteed by SMLP and all of the subsidiaries of Summit Holdings other than the Specified Subsidiaries (as defined in the credit agreement). The credit agreement contains affirmative and negative covenants customary for credit facilities of its size and nature that, among other things, limit or restrict the ability (i) to incur additional debt; (ii) to make investments; (iii) to engage in certain mergers, consolidations, acquisitions or sales of assets; (iv) to enter into swap agreements and power purchase agreements; (v) to enter into leases that would cumulatively obligate payments in excess of $50.0 million over any 12 -month period; and (vi) of Summit Holdings to make distributions, with certain exceptions, including the distribution of Available Cash (as defined in the SMLP partnership agreement) if no default or event of default then exists or would result therefrom and Summit Holdings is in pro forma compliance with its financial covenants. The credit agreement also contains an affirmative covenant that could require our Non-Guarantor Subsidiaries (OpCo, Summit Utica, Meadowlark Midstream and Tioga Midstream) to become guarantor subsidiaries in certain circumstances. In addition, the revolving credit facility requires Summit Holdings to maintain (i) a ratio of consolidated trailing 12 -month earnings before interest, income taxes, depreciation and amortization ("EBITDA") to net interest expense of not less than 2.5 to 1.0 as defined in the credit agreement, (ii) a ratio of total net indebtedness to consolidated trailing 12 -month EBITDA of not more than 5.50 to 1.00 and, (iii) a ratio of first lien net indebtedness to consolidated trailing 12 -month EBITDA of not more than 3.75 to 1.00. As a result of the amendment, SMLP incurred approximately $8.1 million of debt issuance costs. As of June 30, 2017, we had $11.7 million of debt issuance costs attributable to our Revolving Credit Facility and related amendments which are included in noncurrent assets on the unaudited condensed consolidated balance sheet. As of June 30, 2017 , we were in compliance with the Revolving Credit Facility's covenants. There were no defaults or events of default during the six months ended June 30, 2017 . Senior Notes. In June 2013, Summit Holdings and its 100% owned finance subsidiary, Finance Corp. (together with Summit Holdings, the "Co-Issuers") co-issued $300.0 million of 7.5% senior unsecured notes (the " 7.5% Senior Notes"). In July 2014, the Co-Issuers co-issued $300.0 million of 5.5% senior unsecured notes maturing August 15, 2022 (the " 5.5% Senior Notes" and, together with the 5.75% Senior Notes (defined below, the “Senior Notes”). On February 8, 2017, the Co-Issuers completed a public offering of $500.0 million of 5.75% senior unsecured notes (the " 5.75% Senior Notes") as described below. Concurrent with the 5.75% Senior Notes offering, we made a tender offer to purchase all the outstanding 7.5% Senior Notes. The tender offer expired on February 14, 2017 and resulted in approximately $276.9 million of our 7.5% Senior Notes being validly tendered and retired. On February 16, 2017, we issued a notice of redemption for the remaining 7.5% Senior Notes. The remaining $23.1 million of 7.5% Senior Notes were redeemed on March 18, 2017 (the "redemption date"), with payment made on March 20, 2017. References to the “Senior Notes,” when used for dates or periods ended on or after the date of issuance of the 5.75% Senior Notes but before the redemption date, refer collectively to 5.5% Senior Notes, 7.5% Senior Notes and 5.75% Senior Notes. References to the "Senior Notes," when used for dates or periods ended on or prior to the date of issuance of the 5.75% Senior Notes, refer collectively to 5.5% Senior Notes and 7.5% Senior Notes. References to the "Senior Notes," when used for dates or periods that ended after the redemption date, refer collectively to the 5.5% Senior Notes and the 5.75% Senior Notes. In conjunction with the tender offer and mandatory redemption of the 7.5% Senior Notes, we paid redemption and call premiums totaling $17.9 million . These costs, as well as $4.1 million of unamortized debt issuance costs, are presented on our unaudited condensed consolidated statement of operations as early extinguishment of debt. On June 15, 2017, we executed a supplemental indenture and an amendment to our Revolving Credit Facility to add a newly formed entity, Summit Permian, as a guarantor. As a result, Bison Midstream and its subsidiaries, Grand River and its subsidiary, DFW Midstream, Summit Marketing and Summit Permian (collectively the "Guarantor Subsidiaries") and SMLP fully and unconditionally and jointly and severally guarantee the 5.5% Senior Notes and the 5.75% Senior Notes. The Senior Notes are not guaranteed by OpCo, Summit Utica, Meadowlark Midstream and Tioga Midstream (collectively, the "Non-Guarantor Subsidiaries"). There are no significant restrictions on the ability of SMLP or Summit Holdings to obtain funds from its subsidiaries by dividend or loan. Finance Corp. has had no assets or operations since inception in 2013. At no time have the Senior Notes been guaranteed by the Co-Issuers. 5.75% Senior Notes . In February 2017, the Co-Issuers completed a public offering of $500.0 million of 5.75% senior unsecured notes maturing April 15, 2025. Interest on the 5.75% Senior Notes will be paid semi-annually in cash in arrears on April 15 and October 15 of each year, beginning on October 15, 2017. The 5.75% Senior Notes are senior, unsecured obligations and rank equally in right of payment with all of our existing and future senior obligations. The 5.75% Senior Notes are effectively subordinated in right of payment to all of our secured indebtedness, to the extent of the collateral securing such indebtedness. We used the proceeds from the issuance of the 5.75% Senior Notes to (i) fund the repurchase of the outstanding $300.0 million principal 7.5% Senior Notes, (ii) pay redemption and call premiums on the 7.5% Senior Notes totaling $17.9 million and (iii) pay $172.0 million of the balance outstanding under our Revolving Credit Facility. At any time prior to April 15, 2020, the Co-Issuers may redeem up to 35% of the aggregate principal amount of the 5.75% Senior Notes at a redemption price of 105.750% of the principal amount of the 5.75% Senior Notes, plus accrued and unpaid interest, if any, but not including, the redemption date, with an amount not greater than the net cash proceeds of certain equity offerings. On and after April 15, 2020, the Co-Issuers may redeem all or part of the 5.75% Senior Notes at a redemption price of 104.313% (with the redemption premium declining ratably each year to 100.000% on and after April 15, 2023), plus accrued and unpaid interest, if any, to, but not including, the redemption date. Debt issuance costs of $7.5 million are being amortized over the life of the senior notes. The 5.75% Senior Notes' indenture restricts SMLP’s and the Co-Issuers’ ability and the ability of certain of their subsidiaries to: (i) incur additional debt or issue preferred stock; (ii) make distributions, repurchase equity or redeem subordinated debt; (iii) make payments on subordinated indebtedness; (iv) create liens or other encumbrances; (v) make investments, loans or other guarantees; (vi) sell or otherwise dispose of a portion of their assets; (vii) engage in transactions with affiliates; and (viii) make acquisitions or merge or consolidate with another entity. These covenants are subject to a number of important exceptions and qualifications. At any time when the senior notes are rated investment grade by each of Moody’s Investors Service, Inc. and Standard & Poor’s Ratings Services and no default or event of default under the indenture has occurred and is continuing, many of these covenants will terminate. The 5.75% Senior Notes' indenture provides that each of the following is an event of default: (i) default for 30 days in the payment when due of interest on the 5.75% Senior Notes; (ii) default in the payment when due of the principal of, or premium, if any, on the 5.75% Senior Notes; (iii) failure by the Co-Issuers or SMLP to comply with certain covenants relating to mergers and consolidations, change of control or asset sales; (iv) failure by SMLP for 180 days after notice to comply with certain covenants relating to the filing of reports with the SEC; (v) failure by the Co-Issuers or SMLP for 30 days after notice to comply with any of the other agreements in the indenture; (vi) specified defaults under any mortgage, indenture or instrument under which there may be issued or by which there may be secured or evidenced any indebtedness for money borrowed by SMLP or any of its restricted subsidiaries (or the payment of which is guaranteed by SMLP or any of its restricted subsidiaries); (vii) failure by SMLP or any of its restricted subsidiaries to pay certain final judgments aggregating in excess of $75.0 million ; (viii) except as permitted by the indenture, any guarantee of the senior notes shall cease for any reason to be in full force and effect or any guarantor, or any person acting on behalf of any guarantor, shall deny or disaffirm its obligations under its guarantee of the senior notes; and (ix) certain events of bankruptcy, insolvency or reorganization described in the indenture. In the case of an event of default as described in the foregoing clause (ix), all outstanding 5.75% Senior Notes will become due and payable immediately without further action or notice. If any other event of default occurs and is continuing, the trustee or the holders of at least 25% in principal amount of the then outstanding 5.75% Senior Notes may declare all the 5.75% Senior Notes to be due and payable immediately. As of and during the six months ended June 30, 2017, we were in compliance with the covenants governing our Senior Notes. There were no defaults or events of default during the six months ended June 30, 2017. SMP Holdings Credit Facility. SMP Holdings had a $250.0 million revolving credit facility (the "SMP Revolving Credit Facility") and a $200.0 million term loan (the "Term Loan" and, collectively with the SMP Revolving Credit Facility, the "SMP Holdings Credit Facility"). Because funding from the SMP Holdings Credit Facility was used to support the development of the 2016 Drop Down Assets, Summit Investments allocated the SMP Holdings Credit Facility to the Partnership during the common control period. Borrowings under the SMP Holdings Credit Facility incurred interest at LIBOR or a base rate (as defined in the credit agreement) plus an applicable margin. The allocation of activity under the SMP Revolving Credit Facility ended concurrent with the closing of the 2016 Drop Down.

FINANCIAL INSTRUMENTS

FINANCIAL INSTRUMENTS	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
FINANCIAL INSTRUMENTS	FINANCIAL INSTRUMENTS Concentrations of Credit Risk. Financial instruments that potentially subject us to concentrations of credit risk consist of cash and cash equivalents and accounts receivable. We maintain our cash and cash equivalents in bank deposit accounts that frequently exceed federally insured limits. We have not experienced any losses in such accounts and do not believe we are exposed to any significant risk. Accounts receivable primarily comprise amounts due for the gathering, treating and processing services we provide to our customers and also the sale of natural gas liquids resulting from our processing services. This industry concentration has the potential to impact our overall exposure to credit risk, either positively or negatively, in that our customers may be similarly affected by changes in economic, industry or other conditions. We monitor the creditworthiness of our counterparties and can require letters of credit for receivables from counterparties that are judged to have substandard credit, unless the credit risk can otherwise be mitigated. Our top five customers or counterparties accounted for 46% of total accounts receivable at June 30, 2017 , compared with 62% as of December 31, 2016. Fair Value. The carrying amount of cash and cash equivalents, accounts receivable and trade accounts payable reported on the balance sheet approximates fair value due to their short-term maturities. The Deferred Purchase Price Obligation's carrying value is its fair value because carrying value represents the present value of the payment expected to be made in 2020. Our calculation of the Deferred Purchase Price Obligation involves significant assumptions and judgments. Differing assumptions regarding any of these inputs could have a material effect on the ultimate cash payment and the Deferred Purchase Price Obligation. As such, its fair value measurement is classified as a non-recurring Level 3 measurement in the fair value hierarchy because our assumptions and judgments are not observable from objective sources (see Note 16). The Deferred Purchase Price Obligation represents our only Level 3 financial instrument fair value measurement. A rollforward of our Level 3 liability measured at fair value on a recurring basis follows (in thousands). Level 3 liability, January 1, 2017 $ 563,281 Change in fair value 15,825 Level 3 liability, June 30, 2017 $ 579,106 A summary of the estimated fair value of our debt financial instruments follows. June 30, 2017 December 31, 2016 Carrying value Estimated fair value (Level 2) Carrying value Estimated fair value (Level 2) (In thousands) Summit Holdings Revolving Credit Facility $ 491,000 $ 491,000 $ 648,000 $ 648,000 Summit Holdings 5.5% Senior Notes ($300.0 million principal) 296,820 300,250 296,484 294,500 Summit Holdings 5.75% Senior Notes ($500.0 million principal) 492,825 504,167 — — Summit Holdings 7.5% Senior Notes ($300.0 million principal) (1) — — 295,817 316,000 __________ (1) Debt was extinguished following the 5.75% Senior Notes offering in February 2017. In conjunction with the early debt extinguishment, the remaining unamortized debt issuance costs were written off. The carrying value on the balance sheet of the Revolving Credit Facility is its fair value due to its floating interest rate. The fair value for the Senior Notes is based on an average of nonbinding broker quotes as of June 30, 2017 and December 31, 2016. The use of different market assumptions or valuation methodologies may have a material effect on the estimated fair value of the Senior Notes.

PARTNERS' CAPITAL

PARTNERS' CAPITAL	6 Months Ended
	Jun. 30, 2017
Equity [Abstract]
PARTNERS' CAPITAL	PARTNERS' CAPITAL A rollforward of the number of common limited partner and General Partner units follows. Common General Partner Total Units, January 1, 2017 72,111,121 1,471,187 73,582,308 Net units issued under SMLP LTIP 184,277 — 184,277 Units issued under ATM Program 763,548 — 763,548 General Partner 2% contribution — 19,812 19,812 Units, June 30, 2017 73,058,946 1,490,999 74,549,945 Unit Offerings. In February 2017, we completed a secondary underwritten public offering of 4,000,000 SMLP common units held by a subsidiary of Summit Investments pursuant to the 2016 SRS. We did not receive any proceeds from this offering. At-the-market Program. In February 2017, we executed a new equity distribution agreement and filed a prospectus and a prospectus supplement with the SEC for the issuance and sale from time to time of SMLP common units having an aggregate offering price of up to $150.0 million (the "ATM Program"). These sales will be made (i) pursuant to the terms of the equity distribution agreement between us and the sales agents named therein and (ii) by means of ordinary brokers' transactions at market prices, in block transactions or as otherwise agreed between us and the sales agents. Sales of our common units may be made in negotiated transactions or transactions that are deemed to be at-the-market offerings as defined by SEC rules. During the three months ended June 30, 2017, we sold 745,848 units under the ATM Program for aggregate gross proceeds of $17.3 million , and paid approximately $0.2 million as compensation to the sales agents pursuant to the terms of the equity distribution agreement. During the six months ended June 30, 2017, we sold 763,548 units under the ATM Program for aggregate gross proceeds of $17.7 million , and paid approximately $0.2 million as compensation to the sales agents pursuant to the terms of the equity distribution agreement. Following the effectiveness of the new ATM registration statement and after taking into account the aggregate sales price of common units sold under the ATM Program through June 30, 2017, we have the capacity to issue additional common units under the ATM Program up to an aggregate $132.3 million . In June 2017, our General Partner made a capital contribution to maintain its 2% general partner interest in SMLP. Noncontrolling Interest. We have recorded Summit Investments' indirect retained ownership interest in OpCo and its subsidiaries as a noncontrolling interest in the unaudited condensed consolidated financial statements. Summit Investments' Equity in Contributed Subsidiaries. Summit Investments' equity in contributed subsidiaries represents its position in the net assets of the 2016 Drop Down Assets that have been acquired by SMLP. The balance also reflects net income attributable to Summit Investments for the 2016 Drop Down Assets for the periods beginning on their respective acquisition dates by Summit Investments and ending on the date they were acquired by the Partnership. Net income or loss was attributed to Summit Investments for the 2016 Drop Down Assets for the period from January 1, 2016 to March 3, 2016. Although included in partners' capital, any net income or loss attributable to Summit Investments is excluded from the calculation of EPU. Cash Distributions Paid and Declared. We paid the following per-unit distributions during the three and six months ended June 30: Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 Per-unit distributions to unitholders $ 0.575 $ 0.575 $ 1.150 $ 1.150 On July 27, 2017, the Board of Directors of our General Partner declared a distribution of $ 0.575 per unit for the quarterly period ended June 30, 2017. This distribution, which totaled $ 45.0 million , will be paid on August 14, 2017 to unitholders of record at the close of business on August 7, 2017. Incentive Distribution Rights. Our general partner also currently holds IDRs that entitle it to receive increasing percentage allocations, up to a maximum of 50% , of the cash we distribute from operating surplus in excess of $0.46 per unit per quarter. Our payment of IDRs as reported in distributions to unitholders – general partner in the statement of partners' capital during the three and six months ended June 30 follow. Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) IDR payments $ 2,106 $ 1,938 $ 4,206 $ 3,874 For the purposes of calculating net income attributable to General Partner in the statements of operations and partners' capital, the financial impact of IDRs is recognized in respect of the quarter for which the distributions were declared. For the purposes of calculating distributions to unitholders in the statements of partners' capital and cash flows, IDR payments are recognized in the quarter in which they are paid.

EARNINGS PER UNIT

EARNINGS PER UNIT	6 Months Ended
	Jun. 30, 2017
Earnings Per Share [Abstract]
EARNINGS PER UNIT	EARNINGS PER UNIT The following table details the components of EPU. Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands, except per-unit amounts) Numerator for basic and diluted EPU: Net income (loss) attributable to common units $ 8,806 $ (51,222 ) $ 6,029 $ (59,487 ) Denominator for basic and diluted EPU: Weighted-average common units outstanding – basic 72,532 66,587 72,341 66,540 Effect of nonvested phantom units 310 — 367 — Weighted-average common units outstanding – diluted 72,842 66,587 72,708 66,540 Earnings (loss) per limited partner unit: Common unit – basic $ 0.12 $ (0.77 ) $ 0.08 $ (0.89 ) Common unit – diluted $ 0.12 $ (0.77 ) $ 0.08 $ (0.89 ) Nonvested anti-dilutive phantom units excluded from the calculation of diluted EPU — 4 — 250

UNIT-BASED AND NONCASH COMPENSA

UNIT-BASED AND NONCASH COMPENSATION	6 Months Ended
	Jun. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
UNIT-BASED AND NONCASH COMPENSATION	UNIT-BASED AND NONCASH COMPENSATION SMLP Long-Term Incentive Plan. The SMLP LTIP provides for equity awards to eligible officers, employees, consultants and directors of our General Partner and its affiliates. Items to note: • In March 2017, we granted 366,181 phantom units and associated distribution equivalent rights to employees in connection with our annual incentive compensation award cycle. These awards had a grant date fair value of $22.50 and vest ratably over a three -year period. • Also in March 2017, 184,277 phantom units vested. • As of June 30, 2017 , approximately 3.6 million common units remained available for future issuance under the SMLP LTIP.

RELATED-PARTY TRANSACTIONS

RELATED-PARTY TRANSACTIONS	6 Months Ended
	Jun. 30, 2017
Related Party Transactions [Abstract]
RELATED-PARTY TRANSACTIONS	RELATED-PARTY TRANSACTIONS Acquisitions. For information on the 2016 Drop Down and its funding, see Notes 11 and 16 of the 2016 Annual Report. Reimbursement of Expenses from General Partner. Our General Partner and its affiliates do not receive a management fee or other compensation in connection with the management of our business, but will be reimbursed for expenses incurred on our behalf. Under our Partnership Agreement, we reimburse our General Partner and its affiliates for certain expenses incurred on our behalf, including, without limitation, salary, bonus, incentive compensation and other amounts paid to our General Partner's employees and executive officers who perform services necessary to run our business. Our Partnership Agreement provides that our General Partner will determine in good faith the expenses that are allocable to us. The "Due to affiliate" line item on the consolidated balance sheet represents the payables to our General Partner for expenses incurred by it and paid on our behalf. Expenses incurred by the General Partner and reimbursed by us under our Partnership Agreement were as follows: Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) Operation and maintenance expense $ 6,731 $ 6,623 $ 13,612 $ 13,372 General and administrative expense 7,895 7,679 16,190 15,457 Expenses Incurred by Summit Investments. Prior to the 2016 Drop Down, Summit Investments incurred: • certain support expenses and capital expenditures on behalf of the contributed subsidiaries. These transactions were settled periodically through membership interests prior to the respective drop down; • interest expense that was related to capital projects for the contributed subsidiaries. As such, the associated interest expense was allocated to the respective contributed subsidiary's capital projects as a noncash contribution and capitalized into the basis of the asset; and • noncash compensation expense for the SMP net profits interests, which were accounted for as compensatory awards. As such, the annual expense associated with the SMP net profits was allocated to the respective contributed subsidiary and is reflected in general and administrative expenses in the statements of operations. Subsequent to any drop down, these expenses are retrospectively included in the reimbursement of General Partner expenses disclosed above due to common control. In February 2017, SMP Holdings sold 4,000,000 common units representing limited partner interests in SMLP at a price to the public of $24.00 per common unit. Consistent with its obligations under our Partnership Agreement, SMLP paid all costs and expenses of the secondary offering (other than underwriting discounts and fees and expenses of counsel and advisors to SMP Holdings in the sale). SMLP did not receive any of the proceeds from the secondary offering.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	6 Months Ended
	Jun. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Operating Leases. We and Summit Investments lease certain office space and equipment to support our operations. We have determined that our leases are operating leases. We recognize total rent expense incurred or allocated to us in general and administrative expenses. Rent expense related to operating leases, including rent expense incurred on our behalf and allocated to us, was as follows: Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) Rent expense $ 923 $ 745 $ 1,802 $ 1,361 Legal Proceedings. The Partnership is involved in various litigation and administrative proceedings arising in the normal course of business. In the opinion of management, any liabilities that may result from these claims or those arising in the normal course of business would not individually or in the aggregate have a material adverse effect on the Partnership's financial position or results of operations. Environmental Matters. Although we believe that we are in material compliance with applicable environmental regulations, the risk of environmental remediation costs and liabilities are inherent in pipeline ownership and operation. Furthermore, we can provide no assurances that significant environmental remediation costs and liabilities will not be incurred by the Partnership in the future. We are currently not aware of any material contingent liabilities that exist with respect to environmental matters, except as noted below. As described in detail in the 2016 Annual Report, in January 2015, Summit Investments learned of the rupture of a four-inch produced water gathering pipeline on the Meadowlark Midstream system near Williston, North Dakota. The incident, which was covered by Summit Investments' insurance policies, was subject to maximum coverage of $25.0 million from its pollution liability insurance policy and $200.0 million from its property and business interruption insurance policy. Summit Investments exhausted the $25.0 million pollution liability policy in 2015. We submitted property and business interruption claim requests to the insurers and reached a settlement in January 2017. In connection therewith, we recognized $2.6 million of business interruption recoveries and $0.4 million of property recoveries. A rollforward of the aggregate accrued environmental remediation liabilities follows. Total (In thousands) Accrued environmental remediation, January 1, 2017 $ 9,453 Payments made (924 ) Accrued environmental remediation, June 30, 2017 $ 8,529 As of June 30, 2017, we have recognized (i) a current liability for remediation effort expenditures expected to be incurred within the next 12 months and (ii) a noncurrent liability for estimated remediation expenditures and fines expected to be incurred subsequent to June 30, 2018. Each of these amounts represent our best estimate for costs expected to be incurred. Neither of these amounts has been discounted to its present value. While we cannot predict the ultimate outcome of this matter with certainty for Summit Investments or Meadowlark Midstream, especially as it relates to any material liability as a result of any governmental proceeding related to the incident, we believe at this time that it is unlikely that SMLP or its General Partner will be subject to any material liability as a result of any governmental proceeding related to the rupture.

ACQUISITIONS AND DROP DOWN TRAN

ACQUISITIONS AND DROP DOWN TRANSACTIONS	6 Months Ended
	Jun. 30, 2017
Business Combinations [Abstract]
ACQUISITIONS AND DROP DOWN TRANSACTIONS	ACQUISITIONS AND DROP DOWN TRANSACTIONS 2016 Drop Down. On March 3, 2016, SMLP acquired a controlling interest in OpCo, the entity which owns the 2016 Drop Down Assets. These assets include certain natural gas, crude oil and produced water gathering systems located in the Utica Shale, the Williston Basin and the DJ Basin as well as ownership interests in a natural gas gathering system and a condensate stabilization facility, both located in the Utica Shale. The net consideration paid and recognized in connection with the 2016 Drop Down (i) consisted of a cash payment to SMP Holdings of $360.0 million funded with borrowings under our Revolving Credit Facility and a $0.6 million working capital adjustment received in June 2016 (the “Initial Payment”) and (ii) includes the Deferred Purchase Price Obligation payment due in 2020. The Deferred Purchase Price Obligation will be equal to: • six-and-one-half ( 6.5 ) multiplied by the average Business Adjusted EBITDA, as defined below and in the Contribution Agreement, of the 2016 Drop Down Assets for 2018 and 2019, less the G&A Adjuster, as defined in the Contribution Agreement; • less the Initial Payment; • less all capital expenditures incurred for the 2016 Drop Down Assets between the March 3, 2016 and December 31, 2019; • plus all Business Adjusted EBITDA from the 2016 Drop Down Assets between March 3, 2016 and December 31, 2019, less the Cumulative G&A Adjuster, as defined in the Contribution Agreement. Business Adjusted EBITDA is defined as the net income or loss of the 2016 Drop Down Assets for such period: • plus interest expense, income tax expense and depreciation and amortization of the 2016 Drop Down Assets for such period; • plus any adjustments related to MVC shortfall payments, impairments and other noncash expenses or losses with respect to the 2016 Drop Down Assets for such period; • plus any Special Liability Expenses, as defined below and in the Contribution Agreement, for such period; • less interest income and income tax benefit of the 2016 Drop Down Assets for such period; • less adjustments related to any other noncash income or gains with respect to the 2016 Drop Down Assets for such period. Business Adjusted EBITDA shall exclude the effect of any Partnership expenses allocated by or to SMLP or its affiliates in respect of the 2016 Drop Down Assets, such as general and administrative expenses (including compensation-related expenses and professional services fees), transaction costs, allocated interest expense and allocated income tax expense. Special Liability Expenses are defined as any and all expenses incurred by SMLP with respect to the Special Liabilities, as defined in the Contribution Agreement, including fines, legal fees, consulting fees and remediation costs. The present value of the Deferred Purchase Price Obligation will be reflected as a liability on our balance sheet until paid. As of the acquisition date, the estimated future payment obligation (based on management’s estimate of the Partnership’s share of forecasted Business Adjusted EBITDA and capital expenditures for the 2016 Drop Down Assets) was estimated to be $860.3 million and had a net present value of $507.4 million , using a discount rate of 13% . As of June 30, 2017 , Remaining Consideration was estimated to be $793.3 million and the net present value, as recognized on the consolidated balance sheet, was $579.1 million , using a discount rate of 11.5% . Any subsequent changes to the estimated future payment obligation will be calculated using a discounted cash flow model with a commensurate risk-adjusted discount rate. Such changes and the impact on the liability due to the passage of time will be recorded as a change in the Deferred Purchase Price Obligation fair value on the consolidated statements of operations in the period of the change. At the discretion of the Board of Directors of our General Partner, the Deferred Purchase Price Obligation can be paid in cash, SMLP common units or a combination thereof. We currently expect that the Deferred Purchase Price Obligation will be financed with a combination of (i) net proceeds from the sale of common units by us, (ii) the net proceeds from the issuance of senior unsecured debt by us, (iii) borrowings under our Revolving Credit Facility and/or (iv) other internally generated sources of cash. Because of the common control aspects in a drop down transaction, the 2016 Drop Down was deemed a transaction between entities under common control. As such, the 2016 Drop Down has been accounted for on an “as-if pooled” basis for all periods in which common control existed and the Partnership’s financial results retrospectively include the combined financial results of the 2016 Drop Down Assets for all common-control periods. Supplemental Disclosures – As-If Pooled Basis. As a result of accounting for our drop down transactions similar to a pooling of interests, our historical financial statements and those of the acquired drop down assets have been combined to reflect the historical operations, financial position and cash flows of the acquired drop down assets from the date common control began. Revenues and net income for the previously separate entities and the combined amounts, as presented in these unaudited condensed consolidated financial statements follow. Six months ended June 30, 2016 (In thousands) SMLP revenues $ 171,339 2016 Drop Down Assets revenues (1) 8,867 Combined revenues $ 180,206 SMLP net loss $ (56,965 ) 2016 Drop Down Assets net income (1) 2,745 Combined net loss $ (54,220 ) __________ (1) Results are fully reflected in SMLP's results of operations subsequent to closing the respective drop down.

CONDENSED CONSOLIDATING FINANCI

CONDENSED CONSOLIDATING FINANCIAL INFORMATION	6 Months Ended
	Jun. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
CONDENSED CONSOLIDATING FINANCIAL INFORMATION	CONDENSED CONSOLIDATING FINANCIAL INFORMATION The Senior Notes are fully and unconditionally guaranteed, jointly and severally, on a senior unsecured basis by SMLP and the Guarantor Subsidiaries (see Note 9). The following supplemental condensed consolidating financial information reflects SMLP's separate accounts, the combined accounts of the Co-Issuers, the combined accounts of the Guarantor Subsidiaries, the combined accounts of the Non-Guarantor Subsidiaries and the consolidating adjustments for the dates and periods indicated. For purposes of the following consolidating information: • each of SMLP and the Co-Issuers account for their subsidiary investments, if any, under the equity method of accounting; and • the balances and results of operations associated with the assets, liabilities and expenses that were carved out of Summit Investments and allocated to SMLP in connection with the 2016 Drop Down have been attributed to SMLP during the common control period. Condensed Consolidating Balance Sheets. Balance sheets as of June 30, 2017 and December 31, 2016 follow. June 30, 2017 SMLP Co-Issuers Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating adjustments Total (In thousands) Assets Cash and cash equivalents $ 228 $ 79 $ 1,921 $ 360 $ — $ 2,588 Accounts receivable 22 — 45,240 10,575 — 55,837 Other current assets 950 — 1,095 219 — 2,264 Due from affiliate 9,360 14,995 467,452 — (491,807 ) — Total current assets 10,560 15,074 515,708 11,154 (491,807 ) 60,689 Property, plant and equipment, net 9,381 — 1,429,927 420,645 — 1,859,953 Intangible assets, net — — 377,216 24,804 — 402,020 Goodwill — — 16,211 — — 16,211 Investment in equity method investees — — — 701,020 — 701,020 Other noncurrent assets 2,628 11,674 155 — — 14,457 Investment in subsidiaries 2,159,778 3,430,690 — — (5,590,468 ) — Total assets $ 2,182,347 $ 3,457,438 $ 2,339,217 $ 1,157,623 $ (6,082,275 ) $ 3,054,350 Liabilities and Partners' Capital Trade accounts payable $ 703 $ — $ 4,852 $ 4,772 $ — $ 10,327 Accrued expenses 1,729 — 6,020 529 — 8,278 Due to affiliate 482,917 — — 9,360 (491,807 ) 470 Deferred revenue — — 4,745 — — 4,745 Ad valorem taxes payable — — 6,870 425 — 7,295 Accrued interest — 17,015 — — — 17,015 Accrued environmental remediation — — — 6,183 — 6,183 Other current liabilities 3,275 — 2,643 387 — 6,305 Total current liabilities 488,624 17,015 25,130 21,656 (491,807 ) 60,618 Long-term debt — 1,280,645 — — — 1,280,645 Deferred Purchase Price Obligation 579,106 — — — — 579,106 Deferred revenue — — 13,049 — — 13,049 Noncurrent accrued environmental remediation — — — 2,346 — 2,346 Other noncurrent liabilities 3,718 — 3,834 135 7,687 Total liabilities 1,071,448 1,297,660 42,013 24,137 (491,807 ) 1,943,451 Total partners' capital 1,110,899 2,159,778 2,297,204 1,133,486 (5,590,468 ) 1,110,899 Total liabilities and partners' capital $ 2,182,347 $ 3,457,438 $ 2,339,217 $ 1,157,623 $ (6,082,275 ) $ 3,054,350 December 31, 2016 SMLP Co-Issuers Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating adjustments Total (In thousands) Assets Cash and cash equivalents $ 698 $ 51 $ 5,647 $ 1,032 $ — $ 7,428 Accounts receivable 53 — 89,584 7,727 — 97,364 Other current assets 1,526 — 2,328 455 — 4,309 Due from affiliate 14,896 38,013 369,995 — (422,904 ) — Total current assets 17,173 38,064 467,554 9,214 (422,904 ) 109,101 Property, plant and equipment, net 2,266 — 1,440,180 411,225 — 1,853,671 Intangible assets, net — — 396,930 24,522 — 421,452 Goodwill — — 16,211 — — 16,211 Investment in equity method investees — — — 707,415 — 707,415 Other noncurrent assets 1,993 5,198 138 — — 7,329 Investment in subsidiaries 2,132,757 3,347,393 — — (5,480,150 ) — Total assets $ 2,154,189 $ 3,390,655 $ 2,321,013 $ 1,152,376 $ (5,903,054 ) $ 3,115,179 Liabilities and Partners' Capital Trade accounts payable $ 978 $ — $ 9,901 $ 5,372 $ — $ 16,251 Accrued expenses 2,399 114 6,069 2,807 — 11,389 Due to affiliate 408,266 — — 14,896 (422,904 ) 258 Ad valorem taxes payable 16 — 9,717 855 — 10,588 Accrued interest — 17,483 — — — 17,483 Accrued environmental remediation — — — 4,301 — 4,301 Other current liabilities 6,718 — 3,798 955 — 11,471 Total current liabilities 418,377 17,597 29,485 29,186 (422,904 ) 71,741 Long-term debt — 1,240,301 — — — 1,240,301 Deferred Purchase Price Obligation 563,281 — — — — 563,281 Deferred revenue — — 57,465 — — 57,465 Noncurrent accrued environmental remediation — — — 5,152 — 5,152 Other noncurrent liabilities 2,858 — 4,602 106 — 7,566 Total liabilities 984,516 1,257,898 91,552 34,444 (422,904 ) 1,945,506 Total partners' capital 1,169,673 2,132,757 2,229,461 1,117,932 (5,480,150 ) 1,169,673 Total liabilities and partners' capital $ 2,154,189 $ 3,390,655 $ 2,321,013 $ 1,152,376 $ (5,903,054 ) $ 3,115,179 Condensed Consolidating Statements of Operations. For the purposes of the following condensed consolidating statements of operations, we allocate general and administrative expenses recognized at the SMLP parent to the Guarantor Subsidiaries and Non-Guarantor Subsidiaries to reflect what those entities' results would have been had they operated on a stand-alone basis. Statements of operations for the three and six months ended June 30, 2017 and 2016 follow. Three months ended June 30, 2017 SMLP Co-Issuers Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating adjustments Total (In thousands) Revenues: Gathering services and related fees $ — $ — $ 65,654 $ 19,147 $ — $ 84,801 Natural gas, NGLs and condensate sales — — 10,407 188 — 10,595 Other revenues — — 5,880 516 — 6,396 Total revenues — — 81,941 19,851 — 101,792 Costs and expenses: Cost of natural gas and NGLs — — 9,079 20 — 9,099 Operation and maintenance — — 20,917 3,099 — 24,016 General and administrative — — 10,544 2,405 — 12,949 Depreciation and amortization 154 — 24,624 3,910 — 28,688 Transaction costs 119 — — — — 119 Loss on asset sales, net — — 65 2 — 67 Long-lived asset impairment — — 2 1 — 3 Total costs and expenses 273 — 65,231 9,437 — 74,941 Other income 64 — — — — 64 Interest expense — (17,553 ) — — — (17,553 ) Deferred Purchase Price Obligation 5,058 — — — — 5,058 Income (loss) before income taxes and loss from equity method investees 4,849 (17,553 ) 16,710 10,414 — 14,420 Income tax benefit 211 — — — — 211 Loss from equity method investees — — — (3,385 ) — (3,385 ) Equity in earnings of consolidated subsidiaries 6,186 23,739 — — (29,925 ) — Net income $ 11,246 $ 6,186 $ 16,710 $ 7,029 $ (29,925 ) $ 11,246 Three months ended June 30, 2016 SMLP Co-Issuers Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating adjustments Total (In thousands) Revenues: Gathering services and related fees $ — $ — $ 62,677 $ 13,510 $ — $ 76,187 Natural gas, NGLs and condensate sales — — 8,581 — — 8,581 Other revenues — — 4,306 561 — 4,867 Total revenues — — 75,564 14,071 — 89,635 Costs and expenses: Cost of natural gas and NGLs — — 6,864 — — 6,864 Operation and maintenance — — 21,042 2,368 — 23,410 General and administrative — — 10,761 2,115 — 12,876 Depreciation and amortization 154 — 24,757 3,052 — 27,963 Transaction costs 122 — — — — 122 Loss on asset sales, net — — 74 — — 74 Long-lived asset impairment — — 40 529 — 569 Total costs and expenses 276 — 63,538 8,064 — 71,878 Other income 19 — — — — 19 Interest expense — (16,035 ) — — — (16,035 ) Deferred Purchase Price Obligation (17,465 ) — — — — (17,465 ) (Loss) income before income taxes and loss from equity method investees (17,722 ) (16,035 ) 12,026 6,007 — (15,724 ) Income tax expense (360 ) — — — — (360 ) Loss from equity method investees — — — (34,471 ) — (34,471 ) Equity in earnings of consolidated subsidiaries (32,473 ) (16,438 ) — — 48,911 — Net (loss) income $ (50,555 ) $ (32,473 ) $ 12,026 $ (28,464 ) $ 48,911 $ (50,555 ) Six months ended June 30, 2017 SMLP Co-Issuers Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating adjustments Total (In thousands) Revenues: Gathering services and related fees $ — $ — $ 166,336 $ 36,478 $ — $ 202,814 Natural gas, NGLs and condensate sales — — 21,527 188 — 21,715 Other revenues — — 11,841 1,227 — 13,068 Total revenues — — 199,704 37,893 — 237,597 Costs and expenses: Cost of natural gas and NGLs — — 18,128 23 — 18,151 Operation and maintenance — — 41,768 5,940 — 47,708 General and administrative — — 22,762 4,319 — 27,081 Depreciation and amortization 308 — 49,221 7,728 — 57,257 Transaction costs 119 — — — — 119 Loss on asset sales, net — — — 68 2 — 70 Long-lived asset impairment — — 2 285 — 287 Total costs and expenses 427 — 131,949 18,297 — 150,673 Other income 135 — — — — 135 Interest expense — (34,269 ) — — — (34,269 ) Early extinguishment of debt — (22,020 ) — — — (22,020 ) Deferred Purchase Price Obligation (15,825 ) — — — — (15,825 ) (Loss) income before income taxes and loss from equity method investees (16,117 ) (56,289 ) 67,755 19,596 — 14,945 Income tax expense (241 ) — — — — (241 ) Loss from equity method investees — — — (4,041 ) — (4,041 ) Equity in earnings of consolidated subsidiaries 27,021 83,310 — — (110,331 ) — Net income $ 10,663 $ 27,021 $ 67,755 $ 15,555 $ (110,331 ) $ 10,663 Six months ended June 30, 2016 SMLP Co-Issuers Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating adjustments Total (In thousands) Revenues: Gathering services and related fees $ — $ — $ 127,445 $ 26,842 $ — $ 154,287 Natural gas, NGLs and condensate sales — — 16,169 — — 16,169 Other revenues — — 8,674 1,076 — 9,750 Total revenues — — 152,288 27,918 — 180,206 Costs and expenses: Cost of natural gas and NGLs — — 13,154 — — 13,154 Operation and maintenance — — 43,614 5,638 — 49,252 General and administrative — — 20,891 4,864 — 25,755 Depreciation and amortization 270 — 49,429 5,992 — 55,691 Transaction costs 1,296 — — — — 1,296 Loss on asset sales, net — — 11 — — 11 Long-lived asset impairment — — 41 528 — 569 Total costs and expenses 1,566 — 127,140 17,022 — 145,728 Other income 41 — — — — 41 Interest expense (1,441 ) (30,476 ) — — — (31,917 ) Deferred Purchase Price Obligation (24,928 ) — — — — (24,928 ) (Loss) income before income taxes and loss from equity method investees (27,894 ) (30,476 ) 25,148 10,896 — (22,326 ) Income tax expense (283 ) — — — — (283 ) Loss from equity method investees — — — (31,611 ) — (31,611 ) Equity in earnings of consolidated subsidiaries (26,043 ) 4,433 — — 21,610 — Net (loss) income $ (54,220 ) $ (26,043 ) $ 25,148 $ (20,715 ) $ 21,610 $ (54,220 ) Condensed Consolidating Statements of Cash Flows. Statements of cash flows for the six months ended June 30, 2017 and 2016 follow. Six months ended June 30, 2017 SMLP Co-Issuers Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating adjustments Total (In thousands) Cash flows from operating activities: Net cash provided by (used in) operating activities $ 424 $ (32,466 ) $ 114,872 $ 38,511 $ — $ 121,341 Cash flows from investing activities: Capital expenditures (6,412 ) — (21,474 ) (18,026 ) — (45,912 ) Contributions to equity method investees — — — (15,649 ) — (15,649 ) Other, net (521 ) — — — — (521 ) Advances to affiliates 5,536 23,020 (97,460 ) — 68,904 — Net cash used in investing activities (1,397 ) 23,020 (118,934 ) (33,675 ) 68,904 (62,082 ) Cash flows from financing activities: Distributions to unitholders (89,029 ) — — — — (89,029 ) Borrowings under Revolving Credit Facility — 112,500 — — — 112,500 Repayments under Revolving Credit Facility — (269,500 ) — — — (269,500 ) Debt issuance costs — (15,613 ) — — — (15,613 ) Payment of redemption and call premiums on senior notes — (17,913 ) — — — (17,913 ) Proceeds from ATM Program issuances, net of costs 17,259 — — — — 17,259 Contribution from General Partner 465 — — — — 465 Issuance of senior notes — 500,000 — — — 500,000 Tender and redemption of senior notes — (300,000 ) — — — (300,000 ) Other, net (2,632 ) — 336 28 — (2,268 ) Advances from affiliates 74,440 — — (5,536 ) (68,904 ) — Net cash provided by (used in) financing activities 503 9,474 336 (5,508 ) (68,904 ) (64,099 ) Net change in cash and cash equivalents (470 ) 28 (3,726 ) (672 ) — (4,840 ) Cash and cash equivalents, beginning of period 698 51 5,647 1,032 — 7,428 Cash and cash equivalents, end of period $ 228 $ 79 $ 1,921 $ 360 $ — $ 2,588 Six months ended June 30, 2016 SMLP Co-Issuers Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating adjustments Total (In thousands) Cash flows from operating activities: Net cash provided by (used in) operating activities $ 750 $ (28,517 ) $ 119,435 $ 39,832 $ — $ 131,500 Cash flows from investing activities: Capital expenditures (512 ) — (30,745 ) (60,115 ) — (91,372 ) Contributions to equity method investees — — — (15,645 ) — (15,645 ) Acquisitions of gathering systems from affiliate (359,431 ) — — — — (359,431 ) Other, net (435 ) — — — — (435 ) Advances to affiliates (8,978 ) (357,486 ) (93,269 ) — 459,733 — Net cash used in investing activities (369,356 ) (357,486 ) (124,014 ) (75,760 ) 459,733 (466,883 ) Cash flows from financing activities: Distributions to unitholders (82,020 ) — — — — (82,020 ) Borrowings under Revolving Credit Facility 12,000 427,300 — — — 439,300 Repayments under Revolving Credit Facility — (50,300 ) — — — (50,300 ) Debt issuance costs — (2,766 ) — — — (2,766 ) Cash advance from Summit Investments to contributed subsidiaries, net (12,000 ) — — 24,214 — 12,214 Expenses paid by Summit Investments on behalf of contributed subsidiaries 3,030 — — 1,791 — 4,821 Other, net (912 ) — — (4 ) — (916 ) Advances from affiliates 450,755 — — 8,978 (459,733 ) — Net cash provided by financing activities 370,853 374,234 — 34,979 (459,733 ) 320,333 Net change in cash and cash equivalents 2,247 (11,769 ) (4,579 ) (949 ) — (15,050 ) Cash and cash equivalents, beginning of period 73 12,407 6,930 2,383 — 21,793 Cash and cash equivalents, end of period $ 2,320 $ 638 $ 2,351 $ 1,434 $ — $ 6,743

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	6 Months Ended
	Jun. 30, 2017
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS We have evaluated subsequent events for recognition or disclosure in the unaudited condensed consolidated financial statements filed on Form 10-Q with the SEC and no events have occurred that require disclosure, except for the following: In July 2017, our newly formed subsidiary, Summit Midstream Permian, LLC, executed an agreement with XTO Energy Inc. (“XTO”) to develop, own and operate a new associated natural gas gathering and processing system servicing XTO’s crude oil production from certain acreage located in the northern Delaware Basin in Eddy and Lea counties in New Mexico. We will initially construct a gathering and processing system with high and low pressure gathering and discharge pipelines, two compressor stations and a cryogenic processing plant with 60 million cubic feet per day (“MMcf/d”) of processing capacity. Our processing complex will have the ability to be expanded to over 600 MMcf/d of processing capacity, as warranted, to meet customer needs. We expect to process production from XTO and other nearby producers. The initial phase of the project is expected to be operational on or before June 1, 2018 at a total investment cost of approximately $110.0 million .

SUMMARY OF SIGNIFICANT ACCOUN25

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	6 Months Ended
	Jun. 30, 2017
Accounting Policies [Abstract]
Basis of Presentation	Presentation and Consolidation. We prepare our unaudited condensed consolidated financial statements in accordance with GAAP as established by the FASB. We make estimates and assumptions that affect the reported amounts of assets and liabilities at the balance sheet dates, including fair value measurements, the reported amounts of revenue and expense and the disclosure of contingencies. Although management believes these estimates are reasonable, actual results could differ from its estimates. The unaudited condensed consolidated financial statements include the assets, liabilities and results of operations of SMLP and its subsidiaries. All intercompany transactions among the consolidated entities have been eliminated in consolidation. Comprehensive income or loss is the same as net income or loss for all periods presented. The financial position, results of operations and cash flows of acquired drop down assets, liabilities, expenses or entities that were carved out of entities held by Summit Investments and included herein have been derived from the accounting records of the respective Summit Investments' subsidiary on a carve-out basis. SMLP recognized its drop down acquisitions at Summit Investments' historical cost because the acquisitions were executed by entities under common control. The excess of Summit Investments' net investment over the consideration paid and recognized for a contributed subsidiary is recognized as an addition to partners' capital, while the excess of purchase price paid and recognized over net investment is recognized as a reduction to partners' capital. Due to the common control aspect, we account for drop down transactions on an “as-if pooled” basis for the periods during which common control existed. These unaudited condensed consolidated financial statements have been prepared pursuant to the rules and the regulations of the SEC. Certain information and note disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to those rules and regulations. We believe that the disclosures made are adequate to make the information not misleading. In the opinion of management, the unaudited condensed consolidated financial statements contain all adjustments, including normal recurring adjustments, which are necessary to fairly present the unaudited condensed consolidated balance sheet as of June 30, 2017, the unaudited condensed consolidated statements of operations for the three- and six- month periods ended June 30, 2017 and 2016 and the unaudited condensed consolidated statements of partners' capital and cash flows for the six-month periods ended June 30, 2017 and 2016. The balance sheet at December 31, 2016 included herein was derived from our audited financial statements, but does not include all disclosures required by GAAP. These unaudited condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and notes thereto that are included in our annual report on Form 10-K for the year ended December 31, 2016, as filed with the SEC on February 27, 2017 (the "2016 Annual Report"). The results of operations for an interim period are not necessarily indicative of results expected for a full year.
Accounting Pronouncements	There have been no changes to our significant accounting policies since December 31, 2016. Recent Accounting Pronouncements. Accounting standard setters frequently issue new or revised accounting rules. We review new pronouncements to determine the impact, if any, on our financial statements. Accounting standards that have or could possibly have a material effect on our financial statements are discussed below. Recently Adopted Accounting Pronouncements . We have recently adopted the following accounting pronouncements: • ASU No. 2016-09 Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting ("ASU 2016-09"). ASU 2016-09 simplifies several aspects for share-based payment award transactions, including income tax consequences, the liability or equity classification of awards and classification on the statements of cash flows. ASU 2016-09 is effective for public companies for fiscal years beginning after December 15, 2016. It does not specify a single transition approach, rather it specifies retrospective, modified retrospective and/or prospective transition approaches based on the aspect being applied. We adopted the provisions of ASU 2016-09 effective January 1, 2017. The adoption of this standard had no impact on our consolidated financial statements. Accounting Pronouncements Pending Adoption . We are currently in the process of evaluating the applicability and/or impact of the following accounting pronouncements: • ASU No. 2014-09 Revenue from Contracts with Customers (Topic 606) ("ASU 2014-09"). Under ASU 2014-09, revenue will be recognized under a five-step model: (i) identify the contract with the customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to performance obligations; and (v) recognize revenue when (or as) the performance obligation is satisfied. ASU 2014-09 is effective for fiscal years and interim periods within those years, beginning after December 15, 2017 and allows for early adoption. We expect to adopt the provisions of ASU 2014-09 effective January 1, 2018 using the modified retrospective method. We have substantially completed our review of our existing contracts under the new guidance. However, we are still assessing the financial statement impact of adoption for certain items discussed below. For contracts where we perform gathering services and earn a per-unit fee which is recognized at a point in time, revenue will be recognized over time as the service is performed, which is expected to accelerate the recognition of revenue by an immaterial amount. In addition, our contracts generally contain forms of what will be considered variable consideration, which will likely be constrained as the volumes are susceptible to factors outside of our control and influence. However, we will be billing amounts that correspond directly to the value transferred such that the resulting revenue recognized will be similar to current GAAP. We are continuing to evaluate our MVCs and contributions in aid of construction and cannot currently fully conclude on the impact of adoption. We are working with an industry group to develop our position on certain implementation matters. We anticipate that we will be able to complete our assessment of the impact of adoption by the end of the third quarter of 2017. • ASU No. 2016-02 Leases (Topic 842) ("ASU 2016-02"). ASU 2016-02 requires that lessees recognize all leases on the balance sheet, with the exception of short-term leases. A lease liability will be recorded for the obligation of a lessee to make lease payments arising from a lease. A right-of-use asset will be recorded which represents the lessee’s right to use, or to control the use of, a specified asset for a lease term. We are currently evaluating the impact of this guidance on lessor accounting but have made no determinations at this time. ASU 2016-02 is effective for public companies for fiscal years beginning after December 15, 2018, and requires the modified retrospective approach for transition. We are currently evaluating the provisions of ASU 2016-02 to determine its impact on our financial statements and related disclosures and expect to adopt its provisions effective January 1, 2019. • ASU No. 2016-08 Revenue from Contracts with Customers (Topic 606): Principal versus Agent Considerations (Reporting Revenue Gross versus Net) ("ASU 2016-08"). ASU 2016-08 does not change the core principle of Topic 606, rather it clarifies the implementation guidance on principal versus agent considerations. We expect to adopt the provisions of ASU 2016-08 effective January 1, 2018. Our position regarding the impact of and transition method for this update is the same as for ASU 2014-09. • ASU No. 2016-10 Revenue from Contracts with Customers (Topic 606): Identifying Performance Obligations and Licensing ("ASU 2016-10"). ASU 2016-10 clarifies the following two aspects of Topic 606: (i) identifying performance obligations; and (ii) the licensing implementation guidance, while retaining the related principles for those areas. We expect to adopt the provisions of ASU 2016-10 effective January 1, 2018. Our position regarding the impact of and transition method for this update is the same as for ASU 2014-09. • ASU No. 2016-12 Revenue from Contracts with Customers (Topic 606): Narrow-Scope Improvements and Practical Expedients ("ASU 2016-12"). ASU 2016-12 does not change the core principle of the guidance in Topic 606. Rather, the amendments therein affect only the narrow aspects of Topic 606 including assessing the collectability criterion and issues related to contract modification at transition and completed contracts at transition. We expect to adopt the provisions of ASU 2016-12 effective January 1, 2018. Our position regarding the impact of and transition method for this update is the same as for ASU 2014-09.

PROPERTY, PLANT AND EQUIPMENT26

PROPERTY, PLANT AND EQUIPMENT, NET (Tables)	6 Months Ended
	Jun. 30, 2017
Property, Plant and Equipment [Abstract]
Schedule of property, plant, and equipment, net	Details on property, plant and equipment follow. June 30, 2017 December 31, 2016 (In thousands) Gathering and processing systems and related equipment $ 2,067,428 $ 2,026,363 Construction in progress 40,332 39,954 Land and line fill 11,735 11,442 Other 35,083 35,227 Total 2,154,578 2,112,986 Less accumulated depreciation 294,625 259,315 Property, plant and equipment, net $ 1,859,953 $ 1,853,671
Schedule of depreciation expense and capitalized interest	Depreciation expense and capitalized interest follow. Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) Depreciation expense $ 18,607 $ 17,595 $ 37,098 $ 34,966 Capitalized interest 450 1,063 918 1,779

SEGMENT INFORMATION (Tables)

SEGMENT INFORMATION (Tables)	6 Months Ended
	Jun. 30, 2017
Segment Reporting [Abstract]
Schedule of assets by reportable segment	Assets by reportable segment follow. June 30, 2017 December 31, 2016 (In thousands) Assets: Utica Shale $ 213,030 $ 199,392 Ohio Gathering 701,020 707,415 Williston Basin 699,361 724,084 Piceance/DJ Basins 799,058 843,440 Barnett Shale 395,266 404,314 Marcellus Shale 220,899 224,709 Total reportable segment assets 3,028,634 3,103,354 Corporate and other 25,940 12,294 Eliminations (224 ) (469 ) Total assets $ 3,054,350 $ 3,115,179
Schedule of segment reporting information	Revenues by reportable segment follow. Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) Revenues (1): Utica Shale $ 10,456 $ 5,403 $ 19,252 $ 9,686 Williston Basin 29,114 27,507 95,999 57,517 Piceance/DJ Basins 33,763 29,411 68,571 58,402 Barnett Shale 20,904 20,856 38,646 41,257 Marcellus Shale 7,365 6,458 14,269 13,344 Total reportable segments revenue 101,602 89,635 236,737 180,206 Corporate and other 1,362 — 3,148 — Eliminations (1,172 ) — (2,288 ) — Total revenues $ 101,792 $ 89,635 $ 237,597 $ 180,206 __________ (1) Excludes revenues earned by Ohio Gathering due to equity method accounting. Depreciation and amortization, including the amortization expense associated with our favorable and unfavorable gas gathering contracts as reported in other revenues, by reportable segment follows. Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) Depreciation and amortization (1): Utica Shale $ 1,748 $ 952 $ 3,395 $ 1,796 Williston Basin 8,385 8,410 16,766 16,767 Piceance/DJ Basins 12,225 12,297 24,436 24,570 Barnett Shale (2) 3,762 4,057 7,524 8,113 Marcellus Shale 2,263 2,222 4,526 4,441 Total reportable segment depreciation and amortization 28,383 27,938 56,647 55,687 Corporate and other 154 154 308 270 Total depreciation and amortization $ 28,537 $ 28,092 $ 56,955 $ 55,957 __________ (1) Excludes depreciation and amortization recognized by Ohio Gathering due to equity method accounting. (2) Includes the amortization expense associated with our favorable and unfavorable gas gathering contracts as reported in other revenues. Cash paid for capital expenditures by reportable segment follow. Six months ended June 30, 2017 2016 (In thousands) Cash paid for capital expenditures (1): Utica Shale $ 16,473 $ 54,064 Williston Basin 11,085 21,919 Piceance/DJ Basins 11,934 10,633 Barnett Shale (399 ) 2,109 Marcellus Shale 407 2,135 Total reportable segment capital expenditures 39,500 90,860 Corporate and other 6,412 512 Total cash paid for capital expenditures $ 45,912 $ 91,372 __________ (1) Excludes cash paid for capital expenditures by Ohio Gathering due to equity method accounting.
Schedule of counterparties accounting for more than 10% of total revenues	Counterparties accounting for more than 10% of total revenues were as follows: Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 Percentage of total revenues (1)(2): Counterparty A - Piceance Basin 10 % * * * Counterparty B - Barnett Shale 11 % * * * Counterparty C - Utica Shale 10 % * * * Counterparty D - Williston Basin * * 21 % * __________ (1) Includes recognition of revenue that was previously deferred in connection with minimum volume commitments (see Note 8). (2) Excludes revenues earned by Ohio Gathering due to equity method accounting. * Less than 10%
Reconciliation of net income to adjusted EBITDA	Segment adjusted EBITDA by reportable segment follows. Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) Reportable segment adjusted EBITDA: Utica Shale $ 9,533 $ 4,727 $ 17,445 $ 7,916 Ohio Gathering 9,606 12,725 18,679 25,113 Williston Basin 17,155 19,209 34,964 38,929 Piceance/DJ Basins 27,274 26,231 56,248 51,046 Barnett Shale 12,998 13,913 25,086 27,990 Marcellus Shale 5,446 4,807 11,093 9,408 Total of reportable segments’ measures of profit or loss $ 82,012 $ 81,612 $ 163,515 $ 160,402 A reconciliation of income or loss before income taxes and loss from equity method investees to total of reportable segments' measures of profit or loss follows. Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) Reconciliation of income (loss) before income taxes and loss from equity method investees to total of reportable segments' measures of profit or loss: Income (loss) before income taxes and loss from equity method investees $ 14,420 $ (15,724 ) $ 14,945 $ (22,326 ) Add: Corporate and other 9,435 9,247 19,528 18,006 Interest expense 17,553 16,035 34,269 31,917 Early extinguishment of debt — — 22,020 — Deferred Purchase Price Obligation (5,058 ) 17,465 15,825 24,928 Depreciation and amortization 28,537 28,092 56,955 55,957 Proportional adjusted EBITDA for equity method investees 9,606 12,725 18,679 25,113 Adjustments related to MVC shortfall payments 5,578 11,135 (23,062 ) 22,277 Unit-based and noncash compensation 1,871 1,994 3,999 3,950 Loss on asset sales, net 67 74 70 11 Long-lived asset impairment 3 569 287 569 Total of reportable segments' measures of profit or loss $ 82,012 $ 81,612 $ 163,515 $ 160,402
Schedule of Adjustments Related to Minimum Volume Commitments Shortfall Payments	Adjustments related to MVC shortfall payments by reportable segment follow. Three months ended June 30, 2017 Williston Basin Piceance/DJ Basins Barnett Shale Total (In thousands) Adjustments related to MVC shortfall payments: Net change in deferred revenue for MVC shortfall payments $ — $ (1,186 ) $ — $ (1,186 ) Expected MVC shortfall payments 1,982 6,522 (1,740 ) 6,764 Total adjustments related to MVC shortfall payments $ 1,982 $ 5,336 $ (1,740 ) $ 5,578 Three months ended June 30, 2016 Williston Basin Piceance/DJ Basins Barnett Shale Total (In thousands) Adjustments related to MVC shortfall payments: Net change in deferred revenue for MVC shortfall payments $ — $ 1,237 $ (677 ) $ 560 Expected MVC shortfall payments 4,261 6,219 95 10,575 Total adjustments related to MVC shortfall payments $ 4,261 $ 7,456 $ (582 ) $ 11,135 Six months ended June 30, 2017 Williston Basin Piceance/DJ Basins Barnett Shale Total (In thousands) Adjustments related to MVC shortfall payments: Net change in deferred revenue for MVC shortfall payments $ (37,693 ) $ (1,978 ) $ — $ (39,671 ) Expected MVC shortfall payments 3,964 13,067 (422 ) 16,609 Total adjustments related to MVC shortfall payments $ (33,729 ) $ 11,089 $ (422 ) $ (23,062 ) Six months ended June 30, 2016 Williston Basin Piceance/DJ Basins Barnett Shale Total (In thousands) Adjustments related to MVC shortfall payments: Net change in deferred revenue for MVC shortfall payments $ 235 $ 2,475 $ (677 ) $ 2,033 Expected MVC shortfall payments 7,562 12,498 184 20,244 Total adjustments related to MVC shortfall payments $ 7,797 $ 14,973 $ (493 ) $ 22,277

AMORTIZING INTANGIBLE ASSETS 28

AMORTIZING INTANGIBLE ASSETS AND UNFAVORABLE GAS GATHERING CONTRACT (Tables)	6 Months Ended
	Jun. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible assets and liabilities subject to amortization	Details regarding our intangible assets and the unfavorable gas gathering contract (included in other noncurrent liabilities), all of which are subject to amortization, follow. June 30, 2017 Useful lives (In years) Gross carrying amount Accumulated amortization Net (Dollars in thousands) Favorable gas gathering contracts 18.7 $ 24,195 $ (11,572 ) $ 12,623 Contract intangibles 12.5 426,464 (163,570 ) 262,894 Rights-of-way 26.1 154,519 (28,016 ) 126,503 Total intangible assets $ 605,178 $ (203,158 ) $ 402,020 Unfavorable gas gathering contract 10.0 $ 10,962 $ (7,995 ) $ 2,967 December 31, 2016 Useful lives (In years) Gross carrying amount Accumulated amortization Net (Dollars in thousands) Favorable gas gathering contracts 18.7 $ 24,195 $ (10,795 ) $ 13,400 Contract intangibles 12.5 426,464 (146,468 ) 279,996 Rights-of-way 26.1 153,015 (24,959 ) 128,056 Total intangible assets $ 603,674 $ (182,222 ) $ 421,452 Unfavorable gas gathering contract 10.0 $ 10,962 $ (6,916 ) $ 4,046
Recognized amortization expense in other revenues and cost and expenses	We recognized amortization expense in other revenues as follows: Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) Amortization expense – favorable gas gathering contracts $ (388 ) $ (317 ) $ (777 ) $ (655 ) Amortization expense – unfavorable gas gathering contract 539 188 1,079 389 We recognized amortization expense in costs and expenses as follows: Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) Amortization expense – contract intangibles $ 8,551 $ 8,854 $ 17,102 $ 17,708 Amortization expense – rights-of-way 1,530 1,514 3,057 3,017
Estimated aggregate annual amortization expected to be recognized	The estimated aggregate annual amortization expected to be recognized for the remainder of 2017 and each of the four succeeding fiscal years follows. Intangible assets Unfavorable gas gathering contract (In thousands) 2017 $ 21,196 $ 1,079 2018 41,373 1,888 2019 41,204 — 2020 43,453 — 2021 41,679 —

EQUITY METHOD INVESTMENTS (Tabl

EQUITY METHOD INVESTMENTS (Tables)	6 Months Ended
	Jun. 30, 2017
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments	A reconciliation of our 40% ownership interest in Ohio Gathering to our investment per Ohio Gathering's books and records follows (in thousands). Investment in equity method investees, June 30, 2017 $ 701,020 June cash distribution 3,128 June cash contribution (3,484 ) Impairment loss 3,474 Basis difference (136,860 ) Investment in equity method investees, net of basis difference, May 31, 2017 $ 567,278 Summarized statements of operations information for OGC and OCC follows (amounts represent 100% of investee financial information). Results include asset impairments of $8.7 million for the three- and six-month periods ending June 30, 2017 and $94.4 million for the three- and six-month periods ending June 30, 2016. Three months ended May 31, 2017 Three months ended May 31, 2016 OGC OCC OGC OCC (In thousands) Total revenues $ 31,083 $ 2,004 $ 38,444 $ 5,417 Total operating expenses 33,221 1,836 22,572 98,748 Net (loss) income (139 ) 23 15,868 (93,701 ) Six months ended May 31, 2017 Six months ended May 31, 2016 OGC OCC OGC OCC (In thousands) Total revenues $ 68,158 $ 4,057 $ 76,243 $ 10,615 Total operating expenses 60,326 4,309 45,105 103,307 Net income (loss) 7,834 (1,192 ) 31,137 (93,245 )

DEFERRED REVENUE (Tables)

DEFERRED REVENUE (Tables)	6 Months Ended
	Jun. 30, 2017
Deferred Revenue Disclosure [Abstract]
Rollforward of deferred revenue	A rollforward of current deferred revenue follows. Williston Basin Piceance/DJ Basins Total current (In thousands) Current deferred revenue, January 1, 2017 $ — $ — $ — Additions — 12,602 12,602 Less revenue recognized — 7,857 7,857 Current deferred revenue, June 30, 2017 $ — $ 4,745 $ 4,745 A rollforward of noncurrent deferred revenue follows. Williston Basin Piceance/DJ Basins Total noncurrent (In thousands) Noncurrent deferred revenue, January 1, 2017 $ 37,693 $ 19,772 $ 57,465 Less revenue recognized 37,693 1,978 39,671 Less reclassification to current deferred revenue — 4,745 4,745 Noncurrent deferred revenue, June 30, 2017 $ — $ 13,049 $ 13,049

DEBT (Tables)

DEBT (Tables)	6 Months Ended
	Jun. 30, 2017
Debt Disclosure [Abstract]
Schedule of debt and capital leases	Debt consisted of the following: June 30, 2017 December 31, 2016 (In thousands) Summit Holdings variable rate senior secured Revolving Credit Facility (3.73% at June 30, 2017 and 3.27% at December 31, 2016) due May 2022 $ 491,000 $ 648,000 Summit Holdings 5.5% senior unsecured notes due August 2022 300,000 300,000 Less unamortized debt issuance costs (1) (3,180 ) (3,516 ) Summit Holdings 5.75% senior unsecured notes due April 2025 500,000 — Less unamortized debt issuance costs (1) (7,175 ) — Summit Holdings 7.5% senior unsecured notes redeemed March 2017 (2) — 300,000 Less unamortized debt issuance costs (1) (2) — (4,183 ) Total long-term debt $ 1,280,645 $ 1,240,301 __________ (1) Issuance costs are being amortized over the life of the notes. (2) Debt was extinguished following the 5.75% Senior Notes offering in February 2017. In conjunction with the early debt extinguishment, the remaining unamortized debt issuance costs were written off.
Schedule of maturities of long-term debt	The aggregate amount of debt maturing to be recognized for the remainder of 2017 and each of the four succeeding fiscal years follow (in thousands): 2017 $ — 2018 — 2019 — 2020 — 2021 — Thereafter 1,291,000 Total long-term debt $ 1,291,000

FINANCIAL INSTRUMENTS (Tables)

FINANCIAL INSTRUMENTS (Tables)	6 Months Ended
	Jun. 30, 2017
Fair Value Disclosures [Abstract]
Fair value of liabilities measured on recurring basis, unobservable input reconciliation	A rollforward of our Level 3 liability measured at fair value on a recurring basis follows (in thousands). Level 3 liability, January 1, 2017 $ 563,281 Change in fair value 15,825 Level 3 liability, June 30, 2017 $ 579,106
Summary of the estimated fair value of debt instruments	A summary of the estimated fair value of our debt financial instruments follows. June 30, 2017 December 31, 2016 Carrying value Estimated fair value (Level 2) Carrying value Estimated fair value (Level 2) (In thousands) Summit Holdings Revolving Credit Facility $ 491,000 $ 491,000 $ 648,000 $ 648,000 Summit Holdings 5.5% Senior Notes ($300.0 million principal) 296,820 300,250 296,484 294,500 Summit Holdings 5.75% Senior Notes ($500.0 million principal) 492,825 504,167 — — Summit Holdings 7.5% Senior Notes ($300.0 million principal) (1) — — 295,817 316,000 __________ (1) Debt was extinguished following the 5.75% Senior Notes offering in February 2017. In conjunction with the early debt extinguishment, the remaining unamortized debt issuance costs were written off.

PARTNERS' CAPITAL (Tables)

PARTNERS' CAPITAL (Tables)	6 Months Ended
	Jun. 30, 2017
Equity [Abstract]
Schedule of partner units activity	A rollforward of the number of common limited partner and General Partner units follows. Common General Partner Total Units, January 1, 2017 72,111,121 1,471,187 73,582,308 Net units issued under SMLP LTIP 184,277 — 184,277 Units issued under ATM Program 763,548 — 763,548 General Partner 2% contribution — 19,812 19,812 Units, June 30, 2017 73,058,946 1,490,999 74,549,945
Details of cash distributions	We paid the following per-unit distributions during the three and six months ended June 30: Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 Per-unit distributions to unitholders $ 0.575 $ 0.575 $ 1.150 $ 1.150 Our payment of IDRs as reported in distributions to unitholders – general partner in the statement of partners' capital during the three and six months ended June 30 follow. Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) IDR payments $ 2,106 $ 1,938 $ 4,206 $ 3,874

EARNINGS PER UNIT (Tables)

EARNINGS PER UNIT (Tables)	6 Months Ended
	Jun. 30, 2017
Earnings Per Share [Abstract]
Schedule of earnings per limited partner unit	The following table details the components of EPU. Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands, except per-unit amounts) Numerator for basic and diluted EPU: Net income (loss) attributable to common units $ 8,806 $ (51,222 ) $ 6,029 $ (59,487 ) Denominator for basic and diluted EPU: Weighted-average common units outstanding – basic 72,532 66,587 72,341 66,540 Effect of nonvested phantom units 310 — 367 — Weighted-average common units outstanding – diluted 72,842 66,587 72,708 66,540 Earnings (loss) per limited partner unit: Common unit – basic $ 0.12 $ (0.77 ) $ 0.08 $ (0.89 ) Common unit – diluted $ 0.12 $ (0.77 ) $ 0.08 $ (0.89 ) Nonvested anti-dilutive phantom units excluded from the calculation of diluted EPU — 4 — 250

RELATED-PARTY TRANSACTIONS (Tab

RELATED-PARTY TRANSACTIONS (Tables)	6 Months Ended
	Jun. 30, 2017
Related Party Transactions [Abstract]
Schedule of related party transactions	Expenses incurred by the General Partner and reimbursed by us under our Partnership Agreement were as follows: Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) Operation and maintenance expense $ 6,731 $ 6,623 $ 13,612 $ 13,372 General and administrative expense 7,895 7,679 16,190 15,457

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Tables)	6 Months Ended
	Jun. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of total rent expense related to operating leases	Rent expense related to operating leases, including rent expense incurred on our behalf and allocated to us, was as follows: Three months ended June 30, Six months ended June 30, 2017 2016 2017 2016 (In thousands) Rent expense $ 923 $ 745 $ 1,802 $ 1,361
Schedule of accrued environmental remediation	A rollforward of the aggregate accrued environmental remediation liabilities follows. Total (In thousands) Accrued environmental remediation, January 1, 2017 $ 9,453 Payments made (924 ) Accrued environmental remediation, June 30, 2017 $ 8,529

ACQUISITIONS AND DROP DOWN TR37

ACQUISITIONS AND DROP DOWN TRANSACTIONS (Tables)	6 Months Ended
	Jun. 30, 2017
Business Combinations [Abstract]
Business Combination, Revenue and Net Income Disclosures	Revenues and net income for the previously separate entities and the combined amounts, as presented in these unaudited condensed consolidated financial statements follow. Six months ended June 30, 2016 (In thousands) SMLP revenues $ 171,339 2016 Drop Down Assets revenues (1) 8,867 Combined revenues $ 180,206 SMLP net loss $ (56,965 ) 2016 Drop Down Assets net income (1) 2,745 Combined net loss $ (54,220 ) __________ (1) Results are fully reflected in SMLP's results of operations subsequent to closing the respective drop down.

CONDENSED CONSOLIDATING FINAN38

CONDENSED CONSOLIDATING FINANCIAL INFORMATION (Tables)	6 Months Ended
	Jun. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Condensed Balance Sheet	Balance sheets as of June 30, 2017 and December 31, 2016 follow. June 30, 2017 SMLP Co-Issuers Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating adjustments Total (In thousands) Assets Cash and cash equivalents $ 228 $ 79 $ 1,921 $ 360 $ — $ 2,588 Accounts receivable 22 — 45,240 10,575 — 55,837 Other current assets 950 — 1,095 219 — 2,264 Due from affiliate 9,360 14,995 467,452 — (491,807 ) — Total current assets 10,560 15,074 515,708 11,154 (491,807 ) 60,689 Property, plant and equipment, net 9,381 — 1,429,927 420,645 — 1,859,953 Intangible assets, net — — 377,216 24,804 — 402,020 Goodwill — — 16,211 — — 16,211 Investment in equity method investees — — — 701,020 — 701,020 Other noncurrent assets 2,628 11,674 155 — — 14,457 Investment in subsidiaries 2,159,778 3,430,690 — — (5,590,468 ) — Total assets $ 2,182,347 $ 3,457,438 $ 2,339,217 $ 1,157,623 $ (6,082,275 ) $ 3,054,350 Liabilities and Partners' Capital Trade accounts payable $ 703 $ — $ 4,852 $ 4,772 $ — $ 10,327 Accrued expenses 1,729 — 6,020 529 — 8,278 Due to affiliate 482,917 — — 9,360 (491,807 ) 470 Deferred revenue — — 4,745 — — 4,745 Ad valorem taxes payable — — 6,870 425 — 7,295 Accrued interest — 17,015 — — — 17,015 Accrued environmental remediation — — — 6,183 — 6,183 Other current liabilities 3,275 — 2,643 387 — 6,305 Total current liabilities 488,624 17,015 25,130 21,656 (491,807 ) 60,618 Long-term debt — 1,280,645 — — — 1,280,645 Deferred Purchase Price Obligation 579,106 — — — — 579,106 Deferred revenue — — 13,049 — — 13,049 Noncurrent accrued environmental remediation — — — 2,346 — 2,346 Other noncurrent liabilities 3,718 — 3,834 135 7,687 Total liabilities 1,071,448 1,297,660 42,013 24,137 (491,807 ) 1,943,451 Total partners' capital 1,110,899 2,159,778 2,297,204 1,133,486 (5,590,468 ) 1,110,899 Total liabilities and partners' capital $ 2,182,347 $ 3,457,438 $ 2,339,217 $ 1,157,623 $ (6,082,275 ) $ 3,054,350 December 31, 2016 SMLP Co-Issuers Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating adjustments Total (In thousands) Assets Cash and cash equivalents $ 698 $ 51 $ 5,647 $ 1,032 $ — $ 7,428 Accounts receivable 53 — 89,584 7,727 — 97,364 Other current assets 1,526 — 2,328 455 — 4,309 Due from affiliate 14,896 38,013 369,995 — (422,904 ) — Total current assets 17,173 38,064 467,554 9,214 (422,904 ) 109,101 Property, plant and equipment, net 2,266 — 1,440,180 411,225 — 1,853,671 Intangible assets, net — — 396,930 24,522 — 421,452 Goodwill — — 16,211 — — 16,211 Investment in equity method investees — — — 707,415 — 707,415 Other noncurrent assets 1,993 5,198 138 — — 7,329 Investment in subsidiaries 2,132,757 3,347,393 — — (5,480,150 ) — Total assets $ 2,154,189 $ 3,390,655 $ 2,321,013 $ 1,152,376 $ (5,903,054 ) $ 3,115,179 Liabilities and Partners' Capital Trade accounts payable $ 978 $ — $ 9,901 $ 5,372 $ — $ 16,251 Accrued expenses 2,399 114 6,069 2,807 — 11,389 Due to affiliate 408,266 — — 14,896 (422,904 ) 258 Ad valorem taxes payable 16 — 9,717 855 — 10,588 Accrued interest — 17,483 — — — 17,483 Accrued environmental remediation — — — 4,301 — 4,301 Other current liabilities 6,718 — 3,798 955 — 11,471 Total current liabilities 418,377 17,597 29,485 29,186 (422,904 ) 71,741 Long-term debt — 1,240,301 — — — 1,240,301 Deferred Purchase Price Obligation 563,281 — — — — 563,281 Deferred revenue — — 57,465 — — 57,465 Noncurrent accrued environmental remediation — — — 5,152 — 5,152 Other noncurrent liabilities 2,858 — 4,602 106 — 7,566 Total liabilities 984,516 1,257,898 91,552 34,444 (422,904 ) 1,945,506 Total partners' capital 1,169,673 2,132,757 2,229,461 1,117,932 (5,480,150 ) 1,169,673 Total liabilities and partners' capital $ 2,154,189 $ 3,390,655 $ 2,321,013 $ 1,152,376 $ (5,903,054 ) $ 3,115,179
Condensed Statement of Operations	Statements of operations for the three and six months ended June 30, 2017 and 2016 follow. Three months ended June 30, 2017 SMLP Co-Issuers Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating adjustments Total (In thousands) Revenues: Gathering services and related fees $ — $ — $ 65,654 $ 19,147 $ — $ 84,801 Natural gas, NGLs and condensate sales — — 10,407 188 — 10,595 Other revenues — — 5,880 516 — 6,396 Total revenues — — 81,941 19,851 — 101,792 Costs and expenses: Cost of natural gas and NGLs — — 9,079 20 — 9,099 Operation and maintenance — — 20,917 3,099 — 24,016 General and administrative — — 10,544 2,405 — 12,949 Depreciation and amortization 154 — 24,624 3,910 — 28,688 Transaction costs 119 — — — — 119 Loss on asset sales, net — — 65 2 — 67 Long-lived asset impairment — — 2 1 — 3 Total costs and expenses 273 — 65,231 9,437 — 74,941 Other income 64 — — — — 64 Interest expense — (17,553 ) — — — (17,553 ) Deferred Purchase Price Obligation 5,058 — — — — 5,058 Income (loss) before income taxes and loss from equity method investees 4,849 (17,553 ) 16,710 10,414 — 14,420 Income tax benefit 211 — — — — 211 Loss from equity method investees — — — (3,385 ) — (3,385 ) Equity in earnings of consolidated subsidiaries 6,186 23,739 — — (29,925 ) — Net income $ 11,246 $ 6,186 $ 16,710 $ 7,029 $ (29,925 ) $ 11,246 Three months ended June 30, 2016 SMLP Co-Issuers Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating adjustments Total (In thousands) Revenues: Gathering services and related fees $ — $ — $ 62,677 $ 13,510 $ — $ 76,187 Natural gas, NGLs and condensate sales — — 8,581 — — 8,581 Other revenues — — 4,306 561 — 4,867 Total revenues — — 75,564 14,071 — 89,635 Costs and expenses: Cost of natural gas and NGLs — — 6,864 — — 6,864 Operation and maintenance — — 21,042 2,368 — 23,410 General and administrative — — 10,761 2,115 — 12,876 Depreciation and amortization 154 — 24,757 3,052 — 27,963 Transaction costs 122 — — — — 122 Loss on asset sales, net — — 74 — — 74 Long-lived asset impairment — — 40 529 — 569 Total costs and expenses 276 — 63,538 8,064 — 71,878 Other income 19 — — — — 19 Interest expense — (16,035 ) — — — (16,035 ) Deferred Purchase Price Obligation (17,465 ) — — — — (17,465 ) (Loss) income before income taxes and loss from equity method investees (17,722 ) (16,035 ) 12,026 6,007 — (15,724 ) Income tax expense (360 ) — — — — (360 ) Loss from equity method investees — — — (34,471 ) — (34,471 ) Equity in earnings of consolidated subsidiaries (32,473 ) (16,438 ) — — 48,911 — Net (loss) income $ (50,555 ) $ (32,473 ) $ 12,026 $ (28,464 ) $ 48,911 $ (50,555 ) Six months ended June 30, 2017 SMLP Co-Issuers Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating adjustments Total (In thousands) Revenues: Gathering services and related fees $ — $ — $ 166,336 $ 36,478 $ — $ 202,814 Natural gas, NGLs and condensate sales — — 21,527 188 — 21,715 Other revenues — — 11,841 1,227 — 13,068 Total revenues — — 199,704 37,893 — 237,597 Costs and expenses: Cost of natural gas and NGLs — — 18,128 23 — 18,151 Operation and maintenance — — 41,768 5,940 — 47,708 General and administrative — — 22,762 4,319 — 27,081 Depreciation and amortization 308 — 49,221 7,728 — 57,257 Transaction costs 119 — — — — 119 Loss on asset sales, net — — — 68 2 — 70 Long-lived asset impairment — — 2 285 — 287 Total costs and expenses 427 — 131,949 18,297 — 150,673 Other income 135 — — — — 135 Interest expense — (34,269 ) — — — (34,269 ) Early extinguishment of debt — (22,020 ) — — — (22,020 ) Deferred Purchase Price Obligation (15,825 ) — — — — (15,825 ) (Loss) income before income taxes and loss from equity method investees (16,117 ) (56,289 ) 67,755 19,596 — 14,945 Income tax expense (241 ) — — — — (241 ) Loss from equity method investees — — — (4,041 ) — (4,041 ) Equity in earnings of consolidated subsidiaries 27,021 83,310 — — (110,331 ) — Net income $ 10,663 $ 27,021 $ 67,755 $ 15,555 $ (110,331 ) $ 10,663 Six months ended June 30, 2016 SMLP Co-Issuers Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating adjustments Total (In thousands) Revenues: Gathering services and related fees $ — $ — $ 127,445 $ 26,842 $ — $ 154,287 Natural gas, NGLs and condensate sales — — 16,169 — — 16,169 Other revenues — — 8,674 1,076 — 9,750 Total revenues — — 152,288 27,918 — 180,206 Costs and expenses: Cost of natural gas and NGLs — — 13,154 — — 13,154 Operation and maintenance — — 43,614 5,638 — 49,252 General and administrative — — 20,891 4,864 — 25,755 Depreciation and amortization 270 — 49,429 5,992 — 55,691 Transaction costs 1,296 — — — — 1,296 Loss on asset sales, net — — 11 — — 11 Long-lived asset impairment — — 41 528 — 569 Total costs and expenses 1,566 — 127,140 17,022 — 145,728 Other income 41 — — — — 41 Interest expense (1,441 ) (30,476 ) — — — (31,917 ) Deferred Purchase Price Obligation (24,928 ) — — — — (24,928 ) (Loss) income before income taxes and loss from equity method investees (27,894 ) (30,476 ) 25,148 10,896 — (22,326 ) Income tax expense (283 ) — — — — (283 ) Loss from equity method investees — — — (31,611 ) — (31,611 ) Equity in earnings of consolidated subsidiaries (26,043 ) 4,433 — — 21,610 — Net (loss) income $ (54,220 ) $ (26,043 ) $ 25,148 $ (20,715 ) $ 21,610 $ (54,220 )
Condensed Cash Flow Statement	Statements of cash flows for the six months ended June 30, 2017 and 2016 follow. Six months ended June 30, 2017 SMLP Co-Issuers Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating adjustments Total (In thousands) Cash flows from operating activities: Net cash provided by (used in) operating activities $ 424 $ (32,466 ) $ 114,872 $ 38,511 $ — $ 121,341 Cash flows from investing activities: Capital expenditures (6,412 ) — (21,474 ) (18,026 ) — (45,912 ) Contributions to equity method investees — — — (15,649 ) — (15,649 ) Other, net (521 ) — — — — (521 ) Advances to affiliates 5,536 23,020 (97,460 ) — 68,904 — Net cash used in investing activities (1,397 ) 23,020 (118,934 ) (33,675 ) 68,904 (62,082 ) Cash flows from financing activities: Distributions to unitholders (89,029 ) — — — — (89,029 ) Borrowings under Revolving Credit Facility — 112,500 — — — 112,500 Repayments under Revolving Credit Facility — (269,500 ) — — — (269,500 ) Debt issuance costs — (15,613 ) — — — (15,613 ) Payment of redemption and call premiums on senior notes — (17,913 ) — — — (17,913 ) Proceeds from ATM Program issuances, net of costs 17,259 — — — — 17,259 Contribution from General Partner 465 — — — — 465 Issuance of senior notes — 500,000 — — — 500,000 Tender and redemption of senior notes — (300,000 ) — — — (300,000 ) Other, net (2,632 ) — 336 28 — (2,268 ) Advances from affiliates 74,440 — — (5,536 ) (68,904 ) — Net cash provided by (used in) financing activities 503 9,474 336 (5,508 ) (68,904 ) (64,099 ) Net change in cash and cash equivalents (470 ) 28 (3,726 ) (672 ) — (4,840 ) Cash and cash equivalents, beginning of period 698 51 5,647 1,032 — 7,428 Cash and cash equivalents, end of period $ 228 $ 79 $ 1,921 $ 360 $ — $ 2,588 Six months ended June 30, 2016 SMLP Co-Issuers Guarantor Subsidiaries Non-Guarantor Subsidiaries Consolidating adjustments Total (In thousands) Cash flows from operating activities: Net cash provided by (used in) operating activities $ 750 $ (28,517 ) $ 119,435 $ 39,832 $ — $ 131,500 Cash flows from investing activities: Capital expenditures (512 ) — (30,745 ) (60,115 ) — (91,372 ) Contributions to equity method investees — — — (15,645 ) — (15,645 ) Acquisitions of gathering systems from affiliate (359,431 ) — — — — (359,431 ) Other, net (435 ) — — — — (435 ) Advances to affiliates (8,978 ) (357,486 ) (93,269 ) — 459,733 — Net cash used in investing activities (369,356 ) (357,486 ) (124,014 ) (75,760 ) 459,733 (466,883 ) Cash flows from financing activities: Distributions to unitholders (82,020 ) — — — — (82,020 ) Borrowings under Revolving Credit Facility 12,000 427,300 — — — 439,300 Repayments under Revolving Credit Facility — (50,300 ) — — — (50,300 ) Debt issuance costs — (2,766 ) — — — (2,766 ) Cash advance from Summit Investments to contributed subsidiaries, net (12,000 ) — — 24,214 — 12,214 Expenses paid by Summit Investments on behalf of contributed subsidiaries 3,030 — — 1,791 — 4,821 Other, net (912 ) — — (4 ) — (916 ) Advances from affiliates 450,755 — — 8,978 (459,733 ) — Net cash provided by financing activities 370,853 374,234 — 34,979 (459,733 ) 320,333 Net change in cash and cash equivalents 2,247 (11,769 ) (4,579 ) (949 ) — (15,050 ) Cash and cash equivalents, beginning of period 73 12,407 6,930 2,383 — 21,793 Cash and cash equivalents, end of period $ 2,320 $ 638 $ 2,351 $ 1,434 $ — $ 6,743

ORGANIZATION, BUSINESS OPERAT39

ORGANIZATION, BUSINESS OPERATIONS AND PRESENTATION AND CONSOLIDATION (Details) - shares	1 Months Ended	6 Months Ended
	Feb. 29, 2016	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016
ORGANIZATION AND BUSINESS OPERATIONS
Common limited partner capital (shares)		73,059,000	72,111,000
SMP Holdings | Contributed Entities
ORGANIZATION AND BUSINESS OPERATIONS
Percent of issued and outstanding membership interest	100.00%
SMP Holdings | OGC
ORGANIZATION AND BUSINESS OPERATIONS
Percent of issued and outstanding membership interest	40.00%
Drop Down Assets 2016 Acquisition
ORGANIZATION AND BUSINESS OPERATIONS
Ownership interest				1.00%
Common units | Energy Capital Partners
ORGANIZATION AND BUSINESS OPERATIONS
Common limited partner capital (shares)		5,915,827
Common units | SMP Holdings
ORGANIZATION AND BUSINESS OPERATIONS
Common limited partner capital (shares)		25,854,581
General Partner
ORGANIZATION AND BUSINESS OPERATIONS
General partner interest		2.00%
General Partner | Summit Investments | Summit Midstream Partners, LP
ORGANIZATION AND BUSINESS OPERATIONS
General partner interest		2.00%

PROPERTY, PLANT AND EQUIPMENT40

PROPERTY, PLANT AND EQUIPMENT, NET (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 2,154,578		$ 2,154,578		$ 2,112,986
Less accumulated depreciation	294,625		294,625		259,315
Property, plant and equipment, net	1,859,953		1,859,953		1,853,671
Depreciation expense	18,607	$ 17,595	37,098	$ 34,966
Capitalized interest	450	$ 1,063	918	$ 1,779
Gathering and processing systems and related equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,067,428		2,067,428		2,026,363
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	40,332		40,332		39,954
Land and line fill
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	11,735		11,735		11,442
Other
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 35,083		$ 35,083		$ 35,227

SEGMENT INFORMATION - Assets, R

SEGMENT INFORMATION - Assets, Revenues, Depreciation and Amortization, and Capital Expenditures by Reportable Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Segment Reporting Information [Line Items]
Assets	$ 3,054,350		$ 3,054,350		$ 3,115,179
Revenues	101,792	$ 89,635	237,597	$ 180,206
Depreciation and amortization	28,537	28,092	56,955	55,957
Capital expenditures			45,912	91,372
Reportable Segments
Segment Reporting Information [Line Items]
Assets	3,028,634		3,028,634		3,103,354
Revenues	101,602	89,635	236,737	180,206
Depreciation and amortization	28,383	27,938	56,647	55,687
Capital expenditures			39,500	90,860
Reportable Segments | Utica Shale
Segment Reporting Information [Line Items]
Assets	213,030		213,030		199,392
Revenues	10,456	5,403	19,252	9,686
Depreciation and amortization	1,748	952	3,395	1,796
Capital expenditures			16,473	54,064
Reportable Segments | Ohio Gathering
Segment Reporting Information [Line Items]
Assets	701,020		701,020		707,415
Reportable Segments | Williston Basin
Segment Reporting Information [Line Items]
Assets	699,361		699,361		724,084
Revenues	29,114	27,507	95,999	57,517
Depreciation and amortization	8,385	8,410	16,766	16,767
Capital expenditures			11,085	21,919
Reportable Segments | Piceance/DJ Basins
Segment Reporting Information [Line Items]
Assets	799,058		799,058		843,440
Revenues	33,763	29,411	68,571	58,402
Depreciation and amortization	12,225	12,297	24,436	24,570
Capital expenditures			11,934	10,633
Reportable Segments | Barnett Shale
Segment Reporting Information [Line Items]
Assets	395,266		395,266		404,314
Revenues	20,904	20,856	38,646	41,257
Depreciation and amortization	3,762	4,057	7,524	8,113
Capital expenditures			(399)	2,109
Reportable Segments | Marcellus Shale
Segment Reporting Information [Line Items]
Assets	220,899		220,899		224,709
Revenues	7,365	6,458	14,269	13,344
Depreciation and amortization	2,263	2,222	4,526	4,441
Capital expenditures			407	2,135
Corporate and other
Segment Reporting Information [Line Items]
Assets	25,940		25,940		12,294
Revenues	1,362	0	3,148	0
Depreciation and amortization	154	154	308	270
Capital expenditures			6,412	512
Corporate and other | Summit Permian
Segment Reporting Information [Line Items]
Capital expenditures			5,000
Eliminations
Segment Reporting Information [Line Items]
Assets	(224)		(224)		$ (469)
Revenues	$ (1,172)	$ 0	$ (2,288)	$ 0

SEGMENT INFORMATION - Concentra

SEGMENT INFORMATION - Concentration Risk (Details) - Revenue - Customer concentration	3 Months Ended	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2017
Counterparty A - Piceance Basin
Segment Reporting Information [Line Items]
Concentration risk, percentage	10.00%
Counterparty B - Barnett Shale
Segment Reporting Information [Line Items]
Concentration risk, percentage	11.00%
Counterparty C - Utica Shale
Segment Reporting Information [Line Items]
Concentration risk, percentage	10.00%
Counterparty D - Williston Basin
Segment Reporting Information [Line Items]
Concentration risk, percentage		21.00%

SEGMENT INFORMATION - Adjusted

SEGMENT INFORMATION - Adjusted EBITDA by Reportable Segment (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Segment Reporting Information [Line Items]
Adjusted EBITDA	$ 82,012	$ 81,612	$ 163,515	$ 160,402
Utica Shale
Segment Reporting Information [Line Items]
Adjusted EBITDA	9,533	4,727	17,445	7,916
Ohio Gathering
Segment Reporting Information [Line Items]
Adjusted EBITDA	9,606	12,725	18,679	25,113
Williston Basin
Segment Reporting Information [Line Items]
Adjusted EBITDA	17,155	19,209	34,964	38,929
Piceance/DJ Basins
Segment Reporting Information [Line Items]
Adjusted EBITDA	27,274	26,231	56,248	51,046
Barnett Shale
Segment Reporting Information [Line Items]
Adjusted EBITDA	12,998	13,913	25,086	27,990
Marcellus Shale
Segment Reporting Information [Line Items]
Adjusted EBITDA	$ 5,446	$ 4,807	$ 11,093	$ 9,408

SEGMENT INFORMATION - Reconcili

SEGMENT INFORMATION - Reconciliation of Net Income to Adjusted EBITDA (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Segment Reporting [Abstract]
Income (loss) before income taxes and loss from equity method investees	$ 14,420	$ (15,724)	$ 14,945	$ (22,326)
Add:
Corporate and other	9,435	9,247	19,528	18,006
Interest expense	17,553	16,035	34,269	31,917
Early extinguishment of debt	0	0	22,020	0
Deferred Purchase Price Obligation	(5,058)	17,465	15,825	24,928
Depreciation and amortization	28,537	28,092	56,955	55,957
Proportional adjusted EBITDA for equity method investees	9,606	12,725	18,679	25,113
Adjustments related to MVC shortfall payments	5,578	11,135	(23,062)	22,277
Unit-based and noncash compensation	1,871	1,994	3,999	3,950
Loss on asset sales, net	67	74	70	11
Long-lived asset impairment	3	569	287	569
Total of reportable segments' measures of profit or loss	$ 82,012	$ 81,612	$ 163,515	$ 160,402

SEGMENT INFORMATION - Schedule

SEGMENT INFORMATION - Schedule of Adjustments Related to Minimum Volume Commitments Shortfall Payments (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Segment Reporting Information [Line Items]
Net change in deferred revenue for MVC shortfall payments	$ (1,186)	$ 560	$ (39,671)	$ 2,033
Expected MVC shortfall payments	6,764	10,575	16,609	20,244
Total adjustments related to MVC shortfall payments	5,578	11,135	(23,062)	22,277
Williston Basin
Segment Reporting Information [Line Items]
Net change in deferred revenue for MVC shortfall payments	0	0	(37,693)	235
Expected MVC shortfall payments	1,982	4,261	3,964	7,562
Total adjustments related to MVC shortfall payments	1,982	4,261	(33,729)	7,797
Piceance/DJ Basins
Segment Reporting Information [Line Items]
Net change in deferred revenue for MVC shortfall payments	(1,186)	1,237	(1,978)	2,475
Expected MVC shortfall payments	6,522	6,219	13,067	12,498
Total adjustments related to MVC shortfall payments	5,336	7,456	11,089	14,973
Barnett Shale
Segment Reporting Information [Line Items]
Net change in deferred revenue for MVC shortfall payments	0	(677)	0	(677)
Expected MVC shortfall payments	(1,740)	95	(422)	184
Total adjustments related to MVC shortfall payments	$ (1,740)	$ (582)	$ (422)	$ (493)

AMORTIZING INTANGIBLE ASSETS 46

AMORTIZING INTANGIBLE ASSETS AND UNFAVORABLE GAS GATHERING CONTRACT (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 605,178		$ 605,178		$ 603,674
Accumulated amortization	(203,158)		(203,158)		(182,222)
Net	402,020		$ 402,020		$ 421,452
Unfavorable gas gathering contract
Useful lives (In years)			10 years		10 years
Gross carrying amount	10,962		$ 10,962		$ 10,962
Accumulated amortization	(7,995)		(7,995)		(6,916)
Net	2,967		2,967		$ 4,046
Intangible assets
2,017	21,196		21,196
2,018	41,373		41,373
2,019	41,204		41,204
2,020	43,453		43,453
2,021	41,679		41,679
Unfavorable gas gathering contract
2,017	1,079		1,079
2,018	1,888		1,888
2,019	0		0
2,020	0		0
2,021	0		$ 0
Favorable gas gathering contracts
Finite-Lived Intangible Assets [Line Items]
Useful lives (In years)			18 years 8 months 12 days		18 years 8 months 12 days
Gross carrying amount	24,195		$ 24,195		$ 24,195
Accumulated amortization	(11,572)		(11,572)		(10,795)
Net	12,623		12,623		$ 13,400
Amortization expense
Amortization expense	(388)	$ (317)	$ (777)	$ (655)
Contract intangibles
Finite-Lived Intangible Assets [Line Items]
Useful lives (In years)			12 years 6 months		12 years 6 months
Gross carrying amount	426,464		$ 426,464		$ 426,464
Accumulated amortization	(163,570)		(163,570)		(146,468)
Net	262,894		262,894		$ 279,996
Amortization expense
Amortization expense	8,551	8,854	$ 17,102	17,708
Rights-of-way
Finite-Lived Intangible Assets [Line Items]
Useful lives (In years)			26 years 1 month		26 years 1 month
Gross carrying amount	154,519		$ 154,519		$ 153,015
Accumulated amortization	(28,016)		(28,016)		(24,959)
Net	126,503		126,503		$ 128,056
Amortization expense
Amortization expense	1,530	1,514	3,057	3,017
Unfavorable gas gathering contract
Amortization expense
Amortization expense	$ 539	$ 188	$ 1,079	$ 389

GOODWILL (Details)

GOODWILL (Details) - USD ($)	3 Months Ended	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill impairment	$ 0	$ 0

EQUITY METHOD INVESTMENTS - Rol

EQUITY METHOD INVESTMENTS - Rollforward of the Investment in Equity Method Investees (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Equity Method Investment [Roll Forward]
Investment in equity method investees, June 30, 2017	$ 701,020		$ 701,020		$ 701,020
June cash distribution					18,003	$ 24,181
June cash contribution					(15,649)	(15,645)
Investment in equity method investees, net of basis difference, May 31, 2017					707,415
OGC and OCC
Equity Method Investment [Roll Forward]
Impairment loss			8,700	$ 94,400	8,700	$ 94,400
Summit Midstream Partners, LLC | OGC
Equity Method Investment [Roll Forward]
Investment in equity method investees, June 30, 2017	701,020		$ 701,020		$ 701,020
June cash distribution	3,128
June cash contribution	(3,484)
Impairment loss	3,474
Basis difference	(136,860)
Investment in equity method investees, net of basis difference, May 31, 2017	$ 567,278
Principal Owner | OGC
Schedule of Equity Method Investments [Line Items]
Equity method potential ownership interest percent		40.00%		40.00%		40.00%
Ownership percent	40.00%		40.00%		40.00%
Equity Method Investment [Roll Forward]
Impairment loss	$ 3,500	$ 37,800

EQUITY METHOD INVESTMENTS - Sta

EQUITY METHOD INVESTMENTS - Statements of Operations Information (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended		15 Months Ended
	May 31, 2017	May 31, 2017	May 31, 2016	May 31, 2017
OGC
Schedule of Equity Method Investments [Line Items]
Total revenues	$ 31,083	$ 68,158	$ 76,243	$ 38,444
Total operating expenses	33,221	60,326	45,105	22,572
Net (loss) income	(139)	7,834	31,137	15,868
OCC
Schedule of Equity Method Investments [Line Items]
Total revenues	2,004	4,057	10,615	5,417
Total operating expenses	1,836	4,309	103,307	98,748
Net (loss) income	$ 23	$ (1,192)	$ (93,245)	$ (93,701)

DEFERRED REVENUE - Rollforward

DEFERRED REVENUE - Rollforward of deferred revenue (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2017USD ($)
Movement in Deferred Revenue [Roll Forward]
Current deferred revenue, beginning balance	$ 0
Current deferred revenue, Additions	12,602
Current deferred revenue, Less revenue recognized	7,857
Current deferred revenue, ending balance	4,745
Noncurrent deferred revenue, beginning balance	57,465
Less revenue recognized	39,671
Less reclassification to current deferred revenue	4,745
Noncurrent deferred revenue, ending balance	13,049
Williston Basin
Movement in Deferred Revenue [Roll Forward]
Current deferred revenue, beginning balance	0
Current deferred revenue, Additions	0
Current deferred revenue, Less revenue recognized	0
Current deferred revenue, ending balance	0
Noncurrent deferred revenue, beginning balance	37,693
Less revenue recognized	37,693
Less reclassification to current deferred revenue	0
Noncurrent deferred revenue, ending balance	0
Piceance/DJ Basins
Movement in Deferred Revenue [Roll Forward]
Current deferred revenue, beginning balance	0
Current deferred revenue, Additions	12,602
Current deferred revenue, Less revenue recognized	7,857
Current deferred revenue, ending balance	4,745
Noncurrent deferred revenue, beginning balance	19,772
Less revenue recognized	1,978
Less reclassification to current deferred revenue	4,745
Noncurrent deferred revenue, ending balance	$ 13,049

DEFERRED REVENUE - Narrative (D

DEFERRED REVENUE - Narrative (Details) - USD ($)	3 Months Ended	6 Months Ended
	Mar. 31, 2017	Jun. 30, 2017
Deferred Revenue Arrangement [Line Items]
Accounts receivable potentially used to offset fees		$ 0
Recognized amount of deferred revenue		39,671,000
Piceance/DJ Basins
Deferred Revenue Arrangement [Line Items]
Recognized amount of deferred revenue		1,978,000
Piceance/DJ Basins | Gathering Services and Related Fees
Deferred Revenue Arrangement [Line Items]
Recognized amount of deferred revenue	$ 37,700,000
Accrued Income Receivable
Deferred Revenue Arrangement [Line Items]
Shortfall payment billings included in accounts receivable		$ 7,600,000

DEBT - Components of Long-Term

DEBT - Components of Long-Term Debt (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Feb. 08, 2017	Dec. 31, 2016
Line of Credit Facility [Line Items]
Total long-term debt	$ 1,280,645		$ 1,240,301
Senior Notes | 5.5% Senior Notes
Line of Credit Facility [Line Items]
Unsecured notes	300,000		300,000
Less unamortized debt issuance costs	$ (3,180)		(3,516)
Stated interest rate	5.50%
Senior Notes | 5.75% Senior Notes
Line of Credit Facility [Line Items]
Unsecured notes	$ 500,000		0
Less unamortized debt issuance costs	$ (7,175)	$ (7,500)	0
Stated interest rate	5.75%	5.75%
Senior Notes | 7.5% Senior Notes
Line of Credit Facility [Line Items]
Unsecured notes	$ 0		300,000
Less unamortized debt issuance costs	0		$ (4,183)
Stated interest rate			7.50%
Revolving credit facility
Line of Credit Facility [Line Items]
Revolving credit facility	$ 491,000		$ 648,000
Variable interest rate	3.73%		3.27%

DEBT - Maturities (Details)

DEBT - Maturities (Details) $ in Thousands	Jun. 30, 2017USD ($)
Debt Disclosure [Abstract]
2,017	$ 0
2,018	0
2,019	0
2,020	0
2,021	0
Thereafter	1,291,000
Total long-term debt	$ 1,291,000

DEBT - Revolving Credit Facilit

DEBT - Revolving Credit Facility (Details)	6 Months Ended
	Jun. 30, 2017USD ($)	Jun. 30, 2016USD ($)	May 26, 2017	May 25, 2017	Dec. 31, 2016
Line of Credit Facility [Line Items]
Write-off of debt issuance costs	$ 302,000	$ 0
Debt issuance costs	8,100,000
Revolving credit facility
Line of Credit Facility [Line Items]
Borrowing capacity	1,250,000,000
Accordion feature	$ 250,000,000
Leverage ratio			5.50	5
Senior secured leverage ratio	3.75
Commitment fee on unused portion of the facility	0.50%
Cumulative payment obligations, maximum	$ 50,000,000
Debt issuance costs	$ 11,700,000
Interest rate at period end	3.73%				3.27%
Unused portion under the facility	$ 759,000,000
Debt defaults	$ 0
Revolving credit facility | LIBOR
Line of Credit Facility [Line Items]
Applicable margin	2.50%
Revolving credit facility | Minimum
Line of Credit Facility [Line Items]
Commitment fee on unused portion of the facility	0.30%
Ratio of consolidated trailing 12-month EBITDA to net interest expense	2.5
Revolving credit facility | Minimum | ABR
Line of Credit Facility [Line Items]
Applicable margin	0.75%
Revolving credit facility | Minimum | LIBOR
Line of Credit Facility [Line Items]
Applicable margin	1.75%
Revolving credit facility | Maximum
Line of Credit Facility [Line Items]
Commitment fee on unused portion of the facility	0.50%
Ratio of total net indebtedness to consolidated trailing 12-month EBITDA	5.50
Ratio of first lien net indebtedness to consolidated trailing 12-month EBITDA	3.75
Revolving credit facility | Maximum | ABR
Line of Credit Facility [Line Items]
Applicable margin	1.75%
Revolving credit facility | Maximum | LIBOR
Line of Credit Facility [Line Items]
Applicable margin	2.75%

DEBT - Senior Notes (Details)

DEBT - Senior Notes (Details) - USD ($)	Feb. 16, 2017	Feb. 14, 2017	Feb. 28, 2017	Jun. 30, 2013	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Feb. 08, 2017	Dec. 31, 2016	Jul. 31, 2014
Debt Instrument [Line Items]
Gain (loss) on extinguishment of debt					$ 0	$ 0	$ (22,020,000)	$ 0
7.5% Senior Notes | Senior Notes
Debt Instrument [Line Items]
Stated interest rate										7.50%
Debt face amount										$ 300,000,000
Deferred issuance costs					$ 0		$ 0			4,183,000
5.5% Senior Notes | Senior Notes
Debt Instrument [Line Items]
Stated interest rate					5.50%		5.50%
Debt face amount					$ 300,000,000		$ 300,000,000
Deferred issuance costs					$ 3,180,000		$ 3,180,000			3,516,000
5.75% Senior Notes | Senior Notes
Debt Instrument [Line Items]
Stated interest rate					5.75%		5.75%		5.75%
Debt face amount					$ 500,000,000		$ 500,000,000		$ 500,000,000
Deferred issuance costs					$ 7,175,000		7,175,000		$ 7,500,000	$ 0
Default period			30 days
Compliance notice period			30 days
Final judgment			$ 75,000,000
Percent of principal (at least)			25.00%
Redemption period one | 5.75% Senior Notes | Senior Notes
Debt Instrument [Line Items]
Percent of principal redeemed			35.00%
Redemption price, expressed as percentage of principal amount			105.75%
Redemption period two | 5.75% Senior Notes | Senior Notes
Debt Instrument [Line Items]
Redemption price, expressed as percentage of principal amount			104.313%
Redemption period three | 5.75% Senior Notes | Senior Notes
Debt Instrument [Line Items]
Redemption price, expressed as percentage of principal amount			100.00%
Summit Holdings and Finance Corporation | 7.5% Senior Notes | Senior Notes
Debt Instrument [Line Items]
Senior unsecured notes				$ 300,000,000
Stated interest rate				7.50%
Extinguishment of debt	$ 23,100,000	$ 276,900,000
Redemption and call premiums			$ 17,900,000
Summit Holdings and Finance Corporation | 7.5% Senior Notes | Senior Notes | Redemption and Call Premiums
Debt Instrument [Line Items]
Gain (loss) on extinguishment of debt							(17,900,000)
Summit Holdings and Finance Corporation | 7.5% Senior Notes | Senior Notes | Unamortized Debt Issuance Costs
Debt Instrument [Line Items]
Gain (loss) on extinguishment of debt							$ (4,100,000)
Summit Holdings and Finance Corporation | 5.5% Senior Notes | Senior Notes
Debt Instrument [Line Items]
Senior unsecured notes											$ 300,000,000
Stated interest rate											5.50%
Finance Corp | Summit Holdings
Debt Instrument [Line Items]
Cumulative percentage ownership in subsidiary				100.00%
Revolving credit facility
Debt Instrument [Line Items]
Extinguishment of debt			$ 172,000,000

DEBT - SMP Holdings Credit Faci

DEBT - SMP Holdings Credit Facility (Details)	Jun. 30, 2017USD ($)
Revolving credit facility
Debt Instrument [Line Items]
Borrowing capacity	$ 1,250,000,000
SMP Holdings | Senior Secured Term Loan | SMP Holdings Credit Facility
Debt Instrument [Line Items]
Debt face amount	200,000,000
SMP Holdings | Revolving credit facility | SMP Holdings Credit Facility
Debt Instrument [Line Items]
Borrowing capacity	$ 250,000,000

FINANCIAL INSTRUMENTS - Concent

FINANCIAL INSTRUMENTS - Concentration Risk (Details)	6 Months Ended	12 Months Ended
	Jun. 30, 2017	Dec. 31, 2016
Five Largest Customers | Accounts receivable | Customer concentration
CONCENTRATIONS OF RISK
Concentration risk, percentage	46.00%	62.00%

FINANCIAL INSTRUMENTS - Liabili

FINANCIAL INSTRUMENTS - Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation (Details) - Fair Value, Inputs, Level 3 $ in Thousands	6 Months Ended
	Jun. 30, 2017USD ($)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Level 3 liability, January 1, 2017	$ 563,281
Change in fair value	15,825
Level 3 liability, June 30, 2017	$ 579,106

FINANCIAL INSTRUMENTS - Fair va

FINANCIAL INSTRUMENTS - Fair value of Debt Instruments (Details) - USD ($)	Jun. 30, 2017	Feb. 08, 2017	Dec. 31, 2016
Senior Notes | 5.5% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate	5.50%
Debt face amount	$ 300,000,000
Senior Notes | 5.75% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate	5.75%	5.75%
Debt face amount	$ 500,000,000	$ 500,000,000
Senior Notes | 7.5% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Stated interest rate			7.50%
Debt face amount			$ 300,000,000
Carrying value | Revolving credit facility
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Revolving credit facility	491,000,000		648,000,000
Carrying value | Senior Notes | 5.5% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	296,820,000		296,484,000
Carrying value | Senior Notes | 5.75% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	492,825,000		0
Carrying value | Senior Notes | 7.5% Senior Notes
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	0		295,817,000
Estimated fair value (Level 2) | Revolving credit facility | Estimated fair value (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Revolving credit facility	491,000,000		648,000,000
Estimated fair value (Level 2) | Senior Notes | 5.5% Senior Notes | Estimated fair value (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	300,250,000		294,500,000
Estimated fair value (Level 2) | Senior Notes | 5.75% Senior Notes | Estimated fair value (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	504,167,000		0
Estimated fair value (Level 2) | Senior Notes | 7.5% Senior Notes | Estimated fair value (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Senior notes	$ 0		$ 316,000,000

PARTNERS' CAPITAL - Partners' C

PARTNERS' CAPITAL - Partners' Capital and Schedule of Units (Details)	6 Months Ended
	Jun. 30, 2017shares
Rollforwards of the number of partner units
Units, beginning balance (in shares)	73,582,308
Net units issued under SMLP LTIP (in shares)	184,277
Units issued under ATM Program (in shares)	763,548
General Partner 2% contribution (in shares)	19,812
Units, ending balance (in shares)	74,549,945
Common
Rollforwards of the number of partner units
Units, beginning balance (in shares)	72,111,121
Net units issued under SMLP LTIP (in shares)	184,277
Units issued under ATM Program (in shares)	763,548
General Partner 2% contribution (in shares)	0
Units, ending balance (in shares)	73,058,946
General Partner
Rollforwards of the number of partner units
Units, beginning balance (in shares)	1,471,187
Net units issued under SMLP LTIP (in shares)	0
Units issued under ATM Program (in shares)	0
General Partner 2% contribution (in shares)	19,812
Units, ending balance (in shares)	1,490,999
General Partner
Rollforwards of the number of partner units
General partner interest	2.00%

PARTNERS' CAPITAL - Unit Offeri

PARTNERS' CAPITAL - Unit Offerings (Details) - shares	1 Months Ended	6 Months Ended
	Feb. 28, 2017	Jun. 30, 2017
Class of Stock [Line Items]
Units issued under ATM Program (in shares)		763,548
Common
Class of Stock [Line Items]
Units issued under ATM Program (in shares)		763,548
Common | Public Offering
Class of Stock [Line Items]
Units issued under ATM Program (in shares)	4,000,000

PARTNERS' CAPITAL - At-the-mark

PARTNERS' CAPITAL - At-the-market Program (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2017	Jun. 30, 2016	Feb. 28, 2017
Limited Partners' Capital Account [Line Items]
Aggregate gross proceeds		$ 17,259	$ 0
Common | Public Offering
Limited Partners' Capital Account [Line Items]
Aggregate offering price	$ 132,300	$ 132,300		$ 150,000
Amount of stock sold (in shares)	745,848	763,548
Aggregate gross proceeds	$ 17,300	$ 17,700
Compensation paid to sales agents	$ 200	$ 200
General Partner
Limited Partners' Capital Account [Line Items]
General partner interest		2.00%

PARTNERS' CAPITAL - Cash Distri

PARTNERS' CAPITAL - Cash Distributions Paid and Declared (Details) - USD ($) $ / shares in Units, $ in Thousands	Aug. 14, 2017	Jul. 27, 2017	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Distribution Made to Limited Partner [Line Items]
Per-unit annual distributions to unitholders (in dollars per unit)			$ 0.575	$ 0.575	$ 1.150	$ 1.150
Cash paid to unit holders					$ 89,029	$ 82,020
Subsequent Event
Distribution Made to Limited Partner [Line Items]
Per-unit annual distributions to unitholders (in dollars per unit)		$ 0.575
Cash paid to unit holders	$ 45,000

PARTNERS' CAPITAL - Incentive D

PARTNERS' CAPITAL - Incentive Distribution Rights (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Entity Information [Line Items]
Surplus in excess (in dollars per share)			$ 0.46
IDR payments	$ 2,106	$ 1,938	$ 4,206	$ 3,874
Other Ownership Interest
Entity Information [Line Items]
Percentage interest in distributions (maximum)			50.00%

EARNINGS PER UNIT (Details)

EARNINGS PER UNIT (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Numerator for basic and diluted EPU:
Net income (loss) attributable to common units	$ 8,806	$ (51,222)	$ 6,029	$ (59,487)
Denominator for basic and diluted EPU:
Weighted-average common units outstanding (in shares)	72,532	66,587	72,341	66,540
Effect of nonvested phantom units (in shares)	310	0	367	0
Weighted-average common units outstanding – diluted (shares)	72,842	66,587	72,708	66,540
Earnings (loss) per limited partner unit:
Common unit - basic (USD per share)	$ 0.12	$ (0.77)	$ 0.08	$ (0.89)
Common unit - diluted (USD per share)	$ 0.12	$ (0.77)	$ 0.08	$ (0.89)
Phantom Units
Earnings (loss) per limited partner unit:
Nonvested anti-dilutive phantom units excluded from the calculation of diluted EPU (in shares)	0	4	0	250

UNIT-BASED AND NONCASH COMPEN66

UNIT-BASED AND NONCASH COMPENSATION (Details) - SMLP LTIP - $ / shares	1 Months Ended
	Mar. 31, 2017	Jun. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units remaining available (in shares)		3,600,000
Phantom Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted units (in shares)	366,181
Grant date fair value (in dollars per share)	$ 22.50
Vesting period (years)	3 years
Units vested (in shares)	184,277

RELATED-PARTY TRANSACTIONS (Det

RELATED-PARTY TRANSACTIONS (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Feb. 28, 2017	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
SMP Holdings
RELATED-PARTY TRANSACTIONS
Shares sold (in shares)	4,000,000
Sale price (in dollars per share)	$ 24
General Partner | Operation and maintenance expense
RELATED-PARTY TRANSACTIONS
Expenses from transactions with related party		$ 6,731	$ 6,623	$ 13,612	$ 13,372
General Partner | General and administrative expense
RELATED-PARTY TRANSACTIONS
Expenses from transactions with related party		$ 7,895	$ 7,679	$ 16,190	$ 15,457

COMMITMENTS AND CONTINGENCIES -

COMMITMENTS AND CONTINGENCIES - Rent Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Commitments and Contingencies Disclosure [Abstract]
Rent expense	$ 923	$ 745	$ 1,802	$ 1,361

COMMITMENTS AND CONTINGENCIES69

COMMITMENTS AND CONTINGENCIES - Environmental Matters (Details) - USD ($)	1 Months Ended	6 Months Ended	12 Months Ended
	Jan. 31, 2017	Jun. 30, 2017	Dec. 31, 2015
Meadowland Midstream Gathering System
Accrual for Environmental Loss Contingencies [Roll Forward]
Accrued environmental remediation, beginning balance	$ 9,453,000	$ 9,453,000
Payments made		(924,000)
Accrued environmental remediation, ending balance		8,529,000
Maximum | Meadowland Midstream Gathering System | Principal Owner
Loss Contingencies [Line Items]
Coverage from pollution liability insurance policy		25,000,000	$ 25,000,000
Coverage from property and business interruption insurance policy		$ 200,000,000
Business Interruption
Loss Contingencies [Line Items]
Recoveries recognized	2,600,000
Property Recoveries
Loss Contingencies [Line Items]
Recoveries recognized	$ 400,000

ACQUISITIONS AND DROP DOWN TR70

ACQUISITIONS AND DROP DOWN TRANSACTIONS - 2016 Drop Down (Details) - Drop Down Assets 2016 Acquisition $ in Millions	Mar. 03, 2016USD ($)	Jun. 30, 2016USD ($)	Jun. 30, 2017USD ($)
Business Acquisition [Line Items]
Initial payment	$ 360
Working capital adjustment		$ 0.6
Deferred Purchase price obligation, multiple	6.5
Estimated future payment obligation	$ 860.3		$ 793.3
Deferred purchase price obligation	$ 507.4		$ 579.1
Discount rate	13.00%		11.50%

ACQUISITIONS AND DROP DOWN TR71

ACQUISITIONS AND DROP DOWN TRANSACTIONS - Revenue and Net Income (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Business Acquisition [Line Items]
Combined revenues	$ 101,792	$ 89,635	$ 237,597	$ 180,206
Combined net loss	$ 11,246	$ (50,555)	$ 10,663	(54,220)
Summit Midstream Partners, LP
Business Acquisition [Line Items]
Combined revenues				171,339
Combined net loss				(56,965)
Drop Down Assets 2016 Acquisition
Business Acquisition [Line Items]
Combined revenues				8,867
Combined net loss				$ 2,745

CONDENSED CONSOLIDATING FINAN72

CONDENSED CONSOLIDATING FINANCIAL INFORMATION - Condensed Balance Sheet (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Assets
Cash and cash equivalents	$ 2,588	$ 7,428	$ 6,743	$ 21,793
Accounts receivable	55,837	97,364
Other current assets	2,264	4,309
Due from affiliate	0	0
Total current assets	60,689	109,101
Property, plant and equipment, net	1,859,953	1,853,671
Intangible assets, net	402,020	421,452
Goodwill	16,211	16,211
Investment in equity method investees	701,020	707,415
Other noncurrent assets	14,457	7,329
Investment in subsidiaries	0	0
Total assets	3,054,350	3,115,179
Liabilities and Partners' Capital
Trade accounts payable	10,327	16,251
Accrued expenses	8,278	11,389
Due to affiliate	470	258
Deferred revenue	4,745	0
Ad valorem taxes payable	7,295	10,588
Accrued interest	17,015	17,483
Accrued environmental remediation	6,183	4,301
Other current liabilities	6,305	11,471
Total current liabilities	60,618	71,741
Long-term debt	1,280,645	1,240,301
Deferred Purchase Price Obligation	579,106	563,281
Deferred revenue	13,049	57,465
Noncurrent accrued environmental remediation	2,346	5,152
Other noncurrent liabilities	7,687	7,566
Total liabilities	1,943,451	1,945,506
Total partners' capital	1,110,899	1,169,673	1,107,539	1,747,299
Total liabilities and partners' capital	3,054,350	3,115,179
Consolidating adjustments
Assets
Cash and cash equivalents	0	0	0	0
Accounts receivable	0	0
Other current assets	0	0
Due from affiliate	(491,807)	(422,904)
Total current assets	(491,807)	(422,904)
Property, plant and equipment, net	0	0
Intangible assets, net	0	0
Goodwill	0	0
Investment in equity method investees	0	0
Other noncurrent assets	0	0
Investment in subsidiaries	(5,590,468)	(5,480,150)
Total assets	(6,082,275)	(5,903,054)
Liabilities and Partners' Capital
Trade accounts payable	0	0
Accrued expenses	0	0
Due to affiliate	(491,807)	(422,904)
Deferred revenue	0
Ad valorem taxes payable	0	0
Accrued interest	0	0
Accrued environmental remediation	0	0
Other current liabilities	0	0
Total current liabilities	(491,807)	(422,904)
Long-term debt	0	0
Deferred Purchase Price Obligation	0	0
Deferred revenue	0	0
Noncurrent accrued environmental remediation	0	0
Other noncurrent liabilities		0
Total liabilities	(491,807)	(422,904)
Total partners' capital	(5,590,468)	(5,480,150)
Total liabilities and partners' capital	(6,082,275)	(5,903,054)
SMLP | Reportable Legal Entities
Assets
Cash and cash equivalents	228	698	2,320	73
Accounts receivable	22	53
Other current assets	950	1,526
Due from affiliate	9,360	14,896
Total current assets	10,560	17,173
Property, plant and equipment, net	9,381	2,266
Intangible assets, net	0	0
Goodwill	0	0
Investment in equity method investees	0	0
Other noncurrent assets	2,628	1,993
Investment in subsidiaries	2,159,778	2,132,757
Total assets	2,182,347	2,154,189
Liabilities and Partners' Capital
Trade accounts payable	703	978
Accrued expenses	1,729	2,399
Due to affiliate	482,917	408,266
Deferred revenue	0
Ad valorem taxes payable	0	16
Accrued interest	0	0
Accrued environmental remediation	0	0
Other current liabilities	3,275	6,718
Total current liabilities	488,624	418,377
Long-term debt	0	0
Deferred Purchase Price Obligation	579,106	563,281
Deferred revenue	0	0
Noncurrent accrued environmental remediation	0	0
Other noncurrent liabilities	3,718	2,858
Total liabilities	1,071,448	984,516
Total partners' capital	1,110,899	1,169,673
Total liabilities and partners' capital	2,182,347	2,154,189
Co-Issuers | Reportable Legal Entities
Assets
Cash and cash equivalents	79	51	638	12,407
Accounts receivable	0	0
Other current assets	0	0
Due from affiliate	14,995	38,013
Total current assets	15,074	38,064
Property, plant and equipment, net	0	0
Intangible assets, net	0	0
Goodwill	0	0
Investment in equity method investees	0	0
Other noncurrent assets	11,674	5,198
Investment in subsidiaries	3,430,690	3,347,393
Total assets	3,457,438	3,390,655
Liabilities and Partners' Capital
Trade accounts payable	0	0
Accrued expenses	0	114
Due to affiliate	0	0
Deferred revenue	0
Ad valorem taxes payable	0	0
Accrued interest	17,015	17,483
Accrued environmental remediation	0	0
Other current liabilities	0	0
Total current liabilities	17,015	17,597
Long-term debt	1,280,645	1,240,301
Deferred Purchase Price Obligation	0	0
Deferred revenue	0	0
Noncurrent accrued environmental remediation	0	0
Other noncurrent liabilities	0	0
Total liabilities	1,297,660	1,257,898
Total partners' capital	2,159,778	2,132,757
Total liabilities and partners' capital	3,457,438	3,390,655
Guarantor Subsidiaries | Reportable Legal Entities
Assets
Cash and cash equivalents	1,921	5,647	2,351	6,930
Accounts receivable	45,240	89,584
Other current assets	1,095	2,328
Due from affiliate	467,452	369,995
Total current assets	515,708	467,554
Property, plant and equipment, net	1,429,927	1,440,180
Intangible assets, net	377,216	396,930
Goodwill	16,211	16,211
Investment in equity method investees	0	0
Other noncurrent assets	155	138
Investment in subsidiaries	0	0
Total assets	2,339,217	2,321,013
Liabilities and Partners' Capital
Trade accounts payable	4,852	9,901
Accrued expenses	6,020	6,069
Due to affiliate	0	0
Deferred revenue	4,745
Ad valorem taxes payable	6,870	9,717
Accrued interest	0	0
Accrued environmental remediation	0	0
Other current liabilities	2,643	3,798
Total current liabilities	25,130	29,485
Long-term debt	0	0
Deferred Purchase Price Obligation	0	0
Deferred revenue	13,049	57,465
Noncurrent accrued environmental remediation	0	0
Other noncurrent liabilities	3,834	4,602
Total liabilities	42,013	91,552
Total partners' capital	2,297,204	2,229,461
Total liabilities and partners' capital	2,339,217	2,321,013
Non-Guarantor Subsidiaries | Reportable Legal Entities
Assets
Cash and cash equivalents	360	1,032	$ 1,434	$ 2,383
Accounts receivable	10,575	7,727
Other current assets	219	455
Due from affiliate	0	0
Total current assets	11,154	9,214
Property, plant and equipment, net	420,645	411,225
Intangible assets, net	24,804	24,522
Goodwill	0	0
Investment in equity method investees	701,020	707,415
Other noncurrent assets	0	0
Investment in subsidiaries	0	0
Total assets	1,157,623	1,152,376
Liabilities and Partners' Capital
Trade accounts payable	4,772	5,372
Accrued expenses	529	2,807
Due to affiliate	9,360	14,896
Deferred revenue	0
Ad valorem taxes payable	425	855
Accrued interest	0	0
Accrued environmental remediation	6,183	4,301
Other current liabilities	387	955
Total current liabilities	21,656	29,186
Long-term debt	0	0
Deferred Purchase Price Obligation	0	0
Deferred revenue	0	0
Noncurrent accrued environmental remediation	2,346	5,152
Other noncurrent liabilities	135	106
Total liabilities	24,137	34,444
Total partners' capital	1,133,486	1,117,932
Total liabilities and partners' capital	$ 1,157,623	$ 1,152,376

CONDENSED CONSOLIDATING FINAN73

CONDENSED CONSOLIDATING FINANCIAL INFORMATION - Condensed Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Revenues:
Gathering services and related fees	$ 84,801	$ 76,187	$ 202,814	$ 154,287
Natural gas, NGLs and condensate sales	10,595	8,581	21,715	16,169
Other revenues	6,396	4,867	13,068	9,750
Total revenues	101,792	89,635	237,597	180,206
Costs and expenses:
Cost of natural gas and NGLs	9,099	6,864	18,151	13,154
Operation and maintenance	24,016	23,410	47,708	49,252
General and administrative	12,949	12,876	27,081	25,755
Depreciation and amortization	28,688	27,963	57,257	55,691
Transaction costs	119	122	119	1,296
Loss on asset sales, net	67	74	70	11
Long-lived asset impairment	3	569	287	569
Total costs and expenses	74,941	71,878	150,673	145,728
Other income	64	19	135	41
Interest expense	(17,553)	(16,035)	(34,269)	(31,917)
Early extinguishment of debt	0	0	(22,020)	0
Deferred Purchase Price Obligation	5,058	(17,465)	(15,825)	(24,928)
Income (loss) before income taxes and loss from equity method investees	14,420	(15,724)	14,945	(22,326)
Income tax benefit	211	(360)	(241)	(283)
Loss from equity method investees	(3,385)	(34,471)	(4,041)	(31,611)
Equity in earnings of consolidated subsidiaries	0	0	0	0
Net income (loss)	11,246	(50,555)	10,663	(54,220)
Consolidating adjustments
Revenues:
Gathering services and related fees	0	0	0	0
Natural gas, NGLs and condensate sales	0	0	0	0
Other revenues	0	0	0	0
Total revenues	0	0	0	0
Costs and expenses:
Cost of natural gas and NGLs	0	0	0	0
Operation and maintenance	0	0	0	0
General and administrative	0	0	0	0
Depreciation and amortization	0	0	0	0
Transaction costs	0	0	0	0
Loss on asset sales, net	0	0	0	0
Long-lived asset impairment	0	0	0	0
Total costs and expenses	0	0	0	0
Other income	0	0	0	0
Interest expense	0	0	0	0
Early extinguishment of debt			0
Deferred Purchase Price Obligation	0	0	0	0
Income (loss) before income taxes and loss from equity method investees	0	0	0	0
Income tax benefit	0	0	0	0
Loss from equity method investees	0	0	0	0
Equity in earnings of consolidated subsidiaries	(29,925)	48,911	(110,331)	21,610
Net income (loss)	(29,925)	48,911	(110,331)	21,610
SMLP | Reportable Legal Entities
Revenues:
Gathering services and related fees	0	0	0	0
Natural gas, NGLs and condensate sales	0	0	0	0
Other revenues	0	0	0	0
Total revenues	0	0	0	0
Costs and expenses:
Cost of natural gas and NGLs	0	0	0	0
Operation and maintenance	0	0	0	0
General and administrative	0	0	0	0
Depreciation and amortization	154	154	308	270
Transaction costs	119	122	119	1,296
Loss on asset sales, net	0	0	0	0
Long-lived asset impairment	0	0	0	0
Total costs and expenses	273	276	427	1,566
Other income	64	19	135	41
Interest expense	0	0	0	(1,441)
Early extinguishment of debt			0
Deferred Purchase Price Obligation	5,058	(17,465)	(15,825)	(24,928)
Income (loss) before income taxes and loss from equity method investees	4,849	(17,722)	(16,117)	(27,894)
Income tax benefit	211	(360)	(241)	(283)
Loss from equity method investees	0	0	0	0
Equity in earnings of consolidated subsidiaries	6,186	(32,473)	27,021	(26,043)
Net income (loss)	11,246	(50,555)	10,663	(54,220)
Co-Issuers | Reportable Legal Entities
Revenues:
Gathering services and related fees	0	0	0	0
Natural gas, NGLs and condensate sales	0	0	0	0
Other revenues	0	0	0	0
Total revenues	0	0	0	0
Costs and expenses:
Cost of natural gas and NGLs	0	0	0	0
Operation and maintenance	0	0	0	0
General and administrative	0	0	0	0
Depreciation and amortization	0	0	0	0
Transaction costs	0	0	0	0
Loss on asset sales, net	0	0	0	0
Long-lived asset impairment	0	0	0	0
Total costs and expenses	0	0	0	0
Other income	0	0	0	0
Interest expense	(17,553)	(16,035)	(34,269)	(30,476)
Early extinguishment of debt			(22,020)
Deferred Purchase Price Obligation	0	0	0	0
Income (loss) before income taxes and loss from equity method investees	(17,553)	(16,035)	(56,289)	(30,476)
Income tax benefit	0	0	0	0
Loss from equity method investees	0	0	0	0
Equity in earnings of consolidated subsidiaries	23,739	(16,438)	83,310	4,433
Net income (loss)	6,186	(32,473)	27,021	(26,043)
Guarantor Subsidiaries | Reportable Legal Entities
Revenues:
Gathering services and related fees	65,654	62,677	166,336	127,445
Natural gas, NGLs and condensate sales	10,407	8,581	21,527	16,169
Other revenues	5,880	4,306	11,841	8,674
Total revenues	81,941	75,564	199,704	152,288
Costs and expenses:
Cost of natural gas and NGLs	9,079	6,864	18,128	13,154
Operation and maintenance	20,917	21,042	41,768	43,614
General and administrative	10,544	10,761	22,762	20,891
Depreciation and amortization	24,624	24,757	49,221	49,429
Transaction costs	0	0	0	0
Loss on asset sales, net	65	74	68	11
Long-lived asset impairment	2	40	2	41
Total costs and expenses	65,231	63,538	131,949	127,140
Other income	0	0	0	0
Interest expense	0	0	0	0
Early extinguishment of debt			0
Deferred Purchase Price Obligation	0	0	0	0
Income (loss) before income taxes and loss from equity method investees	16,710	12,026	67,755	25,148
Income tax benefit	0	0	0	0
Loss from equity method investees	0	0	0	0
Equity in earnings of consolidated subsidiaries	0	0	0	0
Net income (loss)	16,710	12,026	67,755	25,148
Non-Guarantor Subsidiaries | Reportable Legal Entities
Revenues:
Gathering services and related fees	19,147	13,510	36,478	26,842
Natural gas, NGLs and condensate sales	188	0	188	0
Other revenues	516	561	1,227	1,076
Total revenues	19,851	14,071	37,893	27,918
Costs and expenses:
Cost of natural gas and NGLs	20	0	23	0
Operation and maintenance	3,099	2,368	5,940	5,638
General and administrative	2,405	2,115	4,319	4,864
Depreciation and amortization	3,910	3,052	7,728	5,992
Transaction costs	0	0	0	0
Loss on asset sales, net	2	0	2	0
Long-lived asset impairment	1	529	285	528
Total costs and expenses	9,437	8,064	18,297	17,022
Other income	0	0	0	0
Interest expense	0	0	0	0
Early extinguishment of debt			0
Deferred Purchase Price Obligation	0	0	0	0
Income (loss) before income taxes and loss from equity method investees	10,414	6,007	19,596	10,896
Income tax benefit	0	0	0	0
Loss from equity method investees	(3,385)	(34,471)	(4,041)	(31,611)
Equity in earnings of consolidated subsidiaries	0	0	0	0
Net income (loss)	$ 7,029	$ (28,464)	$ 15,555	$ (20,715)

CONDENSED CONSOLIDATING FINAN74

CONDENSED CONSOLIDATING FINANCIAL INFORMATION - Condensed Cash Flow Statement (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	$ 121,341	$ 131,500
Cash flows from investing activities:
Capital expenditures	(45,912)	(91,372)
Contributions to equity method investees	(15,649)	(15,645)
Acquisitions of gathering systems from affiliate	0	(359,431)
Other, net	(521)	(435)
Advances to affiliates	0	0
Net cash used in investing activities	(62,082)	(466,883)
Cash flows from financing activities:
Distributions to unitholders	(89,029)	(82,020)
Borrowings under Revolving Credit Facility	112,500	439,300
Repayments under Revolving Credit Facility	(269,500)	(50,300)
Debt issuance costs	(15,613)	(2,766)
Cash advance from Summit Investments to contributed subsidiaries, net	0	12,214
Payment of redemption and call premiums on senior notes	(17,913)	0
Proceeds from ATM Program issuances, net of costs	17,259	0
Contribution from General Partner	465	0
Expenses paid by Summit Investments on behalf of contributed subsidiaries	0	4,821
Issuance of senior notes	500,000	0
Tender and redemption of senior notes	(300,000)	0
Other, net	(2,268)	(916)
Advances from affiliates	0	0
Net cash (used in) provided by financing activities	(64,099)	320,333
Net change in cash and cash equivalents	(4,840)	(15,050)
Cash and cash equivalents, beginning of period	7,428	21,793
Cash and cash equivalents, end of period	2,588	6,743
Consolidating adjustments
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	0	0
Cash flows from investing activities:
Capital expenditures	0	0
Contributions to equity method investees	0	0
Acquisitions of gathering systems from affiliate		0
Other, net	0	0
Advances to affiliates	68,904	459,733
Net cash used in investing activities	68,904	459,733
Cash flows from financing activities:
Distributions to unitholders	0	0
Borrowings under Revolving Credit Facility	0	0
Repayments under Revolving Credit Facility	0	0
Debt issuance costs	0	0
Cash advance from Summit Investments to contributed subsidiaries, net		0
Payment of redemption and call premiums on senior notes	0
Proceeds from ATM Program issuances, net of costs	0
Contribution from General Partner	0
Expenses paid by Summit Investments on behalf of contributed subsidiaries		0
Issuance of senior notes	0
Tender and redemption of senior notes	0
Other, net	0	0
Advances from affiliates	(68,904)	(459,733)
Net cash (used in) provided by financing activities	(68,904)	(459,733)
Net change in cash and cash equivalents	0	0
Cash and cash equivalents, beginning of period	0	0
Cash and cash equivalents, end of period	0	0
SMLP | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	424	750
Cash flows from investing activities:
Capital expenditures	(6,412)	(512)
Contributions to equity method investees	0	0
Acquisitions of gathering systems from affiliate		(359,431)
Other, net	(521)	(435)
Advances to affiliates	5,536	(8,978)
Net cash used in investing activities	(1,397)	(369,356)
Cash flows from financing activities:
Distributions to unitholders	(89,029)	(82,020)
Borrowings under Revolving Credit Facility	0	12,000
Repayments under Revolving Credit Facility	0	0
Debt issuance costs	0	0
Cash advance from Summit Investments to contributed subsidiaries, net		(12,000)
Payment of redemption and call premiums on senior notes	0
Proceeds from ATM Program issuances, net of costs	17,259
Contribution from General Partner	465
Expenses paid by Summit Investments on behalf of contributed subsidiaries		3,030
Issuance of senior notes	0
Tender and redemption of senior notes	0
Other, net	(2,632)	(912)
Advances from affiliates	74,440	450,755
Net cash (used in) provided by financing activities	503	370,853
Net change in cash and cash equivalents	(470)	2,247
Cash and cash equivalents, beginning of period	698	73
Cash and cash equivalents, end of period	228	2,320
Co-Issuers | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	(32,466)	(28,517)
Cash flows from investing activities:
Capital expenditures	0	0
Contributions to equity method investees	0	0
Acquisitions of gathering systems from affiliate		0
Other, net	0	0
Advances to affiliates	23,020	(357,486)
Net cash used in investing activities	23,020	(357,486)
Cash flows from financing activities:
Distributions to unitholders	0	0
Borrowings under Revolving Credit Facility	112,500	427,300
Repayments under Revolving Credit Facility	(269,500)	(50,300)
Debt issuance costs	(15,613)	(2,766)
Cash advance from Summit Investments to contributed subsidiaries, net		0
Payment of redemption and call premiums on senior notes	(17,913)
Proceeds from ATM Program issuances, net of costs	0
Contribution from General Partner	0
Expenses paid by Summit Investments on behalf of contributed subsidiaries		0
Issuance of senior notes	500,000
Tender and redemption of senior notes	(300,000)
Other, net	0	0
Advances from affiliates	0	0
Net cash (used in) provided by financing activities	9,474	374,234
Net change in cash and cash equivalents	28	(11,769)
Cash and cash equivalents, beginning of period	51	12,407
Cash and cash equivalents, end of period	79	638
Guarantor Subsidiaries | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	114,872	119,435
Cash flows from investing activities:
Capital expenditures	(21,474)	(30,745)
Contributions to equity method investees	0	0
Acquisitions of gathering systems from affiliate		0
Other, net	0	0
Advances to affiliates	(97,460)	(93,269)
Net cash used in investing activities	(118,934)	(124,014)
Cash flows from financing activities:
Distributions to unitholders	0	0
Borrowings under Revolving Credit Facility	0	0
Repayments under Revolving Credit Facility	0	0
Debt issuance costs	0	0
Cash advance from Summit Investments to contributed subsidiaries, net		0
Payment of redemption and call premiums on senior notes	0
Proceeds from ATM Program issuances, net of costs	0
Contribution from General Partner	0
Expenses paid by Summit Investments on behalf of contributed subsidiaries		0
Issuance of senior notes	0
Tender and redemption of senior notes	0
Other, net	336	0
Advances from affiliates	0	0
Net cash (used in) provided by financing activities	336	0
Net change in cash and cash equivalents	(3,726)	(4,579)
Cash and cash equivalents, beginning of period	5,647	6,930
Cash and cash equivalents, end of period	1,921	2,351
Non-Guarantor Subsidiaries | Reportable Legal Entities
Condensed Cash Flow Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	38,511	39,832
Cash flows from investing activities:
Capital expenditures	(18,026)	(60,115)
Contributions to equity method investees	(15,649)	(15,645)
Acquisitions of gathering systems from affiliate		0
Other, net	0	0
Advances to affiliates	0	0
Net cash used in investing activities	(33,675)	(75,760)
Cash flows from financing activities:
Distributions to unitholders	0	0
Borrowings under Revolving Credit Facility	0	0
Repayments under Revolving Credit Facility	0	0
Debt issuance costs	0	0
Cash advance from Summit Investments to contributed subsidiaries, net		24,214
Payment of redemption and call premiums on senior notes	0
Proceeds from ATM Program issuances, net of costs	0
Contribution from General Partner	0
Expenses paid by Summit Investments on behalf of contributed subsidiaries		1,791
Issuance of senior notes	0
Tender and redemption of senior notes	0
Other, net	28	(4)
Advances from affiliates	(5,536)	8,978
Net cash (used in) provided by financing activities	(5,508)	34,979
Net change in cash and cash equivalents	(672)	(949)
Cash and cash equivalents, beginning of period	1,032	2,383
Cash and cash equivalents, end of period	$ 360	$ 1,434

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details) - Subsequent Event $ in Millions	1 Months Ended
	Jul. 31, 2017USD ($)stationMMcf
Subsequent Event [Line Items]
Compressor stations added | station	2
Cryogenic plant processing capacity (mmcf)	60
Processing complex processing capacity (mmcf)	600
Total investment cost | $	$ 110