EQM Midstream Partners 10-Q 23 Oct 14 2014 Q3 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	9 Months Ended
	Sep. 30, 2014
Entity Registrant Name	'EQT Midstream Partners, LP
Entity Central Index Key	'0001540947
Document Type	'10-Q
Document Period End Date	30-Sep-14
Amendment Flag	'false
Current Fiscal Year End Date	'--12-31
Entity Current Reporting Status	'Yes
Entity Filer Category	'Accelerated Filer
Entity Common Units, Units Outstanding	43,347,452
Document Fiscal Year Focus	'2014
Document Fiscal Period Focus	'Q3
Subordinated Units	'
Entity Common Units, Units Outstanding	17,339,718
General Partner Units outstanding	'
Entity Common Units, Units Outstanding	1,238,514

Statements_of_Consolidated_Ope

Statements of Consolidated Operations (Unaudited) (USD $)	3 Months Ended				9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Operating revenues:	'		'		'		'
Operating revenues – affiliate	$61,641	[1]	$67,377	[1]	$176,766	[1]	$193,188	[1]
Operating revenues – third party	34,203	[1]	10,099	[1]	104,057	[1]	29,511	[1]
Total operating revenues	95,844	[1]	77,476	[1]	280,823	[1]	222,699	[1]
Operating expenses:	'		'		'		'
Operating and maintenance	11,710	[1],[2]	9,740	[1],[2]	33,267	[1],[2]	26,020	[1],[2]
Selling, general and administrative	9,901	[1],[2]	7,188	[1],[2]	30,931	[1],[2]	21,299	[1],[2]
Depreciation and amortization	9,846	[1]	6,624	[1]	26,742	[1],[3]	19,323	[1],[3]
Total operating expenses	31,457	[1]	23,552	[1]	90,940	[1]	66,642	[1]
Operating income	64,387	[1]	53,924	[1]	189,883	[1]	156,057	[1]
Other income, net	806	[1]	319	[1]	1,634	[1]	845	[1]
Interest expense, net	8,660	[1],[4]	196	[1],[4]	20,944	[1],[4]	613	[1],[4]
Income before income taxes	56,533	[1]	54,047	[1]	170,573	[1]	156,289	[1]
Income tax expense	0	[1]	9,993	[1]	12,456	[1]	31,841	[1]
Net income	56,533	[1]	44,054	[1]	158,117	[1],[3]	124,448	[1],[3]
Calculation of limited partner interest in net income:	'		'		'		'
Net income	56,533	[1]	44,054	[1]	158,117	[1],[3]	124,448	[1],[3]
Less pre-acquisition net income allocated to parent	0	[1]	16,338	[1]	20,151	[1]	51,622	[1]
Less general partner interest in net income	4,540	[1]	755	[1]	9,055	[1]	1,726	[1]
Limited partner interest in net income	$51,993	[1]	$26,961	[1]	$128,911	[1]	$71,100	[1]
Net income per limited partner unit - basic (in dollars per unit)	$0.86	[1]	$0.61	[1]	$2.38	[1]	$1.84	[1]
Net income per limited partner unit - diluted (in dollars per unit)	$0.85	[1]	$0.60	[1]	$2.37	[1]	$1.84	[1]
Weighted average limited partner units outstanding - basic (in shares)	60,699	[1]	44,526	[1]	54,259	[1]	38,618	[1]
Weighted average limited partner units outstanding - diluted (in shares)	60,827	[1]	44,639	[1]	54,384	[1]	38,731	[1]
Cash distributions declared per unit (in dollars per share)	$0.55	[1],[5]	$0.43	[1],[5]	$1.56	[1],[5]	$1.20	[1],[5]
[1]	Financial statements for the nine months ended September 30, 2014 and the three months ended September 30, 2013 have been retrospectively recast to reflect the inclusion of the Jupiter natural gas gathering system (Jupiter). Financial statements for the nine months ended September 30, 2013 have been retrospectively recast to reflect the inclusion of Jupiter and Sunrise Pipeline, LLC (Sunrise). See Note B.
[2]	Operating and maintenance expense includes charges from EQT Corporation and its subsidiaries (collectively, EQT) of $6.4 million and $4.9 million for the three months ended September 30, 2014 and 2013, respectively, and $18.0 million and $13.9 million for the nine months ended September 30, 2014 and 2013, respectively. Selling, general and administrative expense includes charges from EQT of $7.9 million and $6.6 million for the three months ended September 30, 2014 and 2013, respectively, and $23.7 million and $19.0 million for the nine months ended September 30, 2014 and 2013, respectively. See Note D.
[3]	Financial statements for the nine months ended September 30, 2014 have been retrospectively recast to reflect the inclusion of Jupiter. Financial statements for the nine months ended September 30, 2013 have been retrospectively recast to reflect the inclusion of Jupiter and Sunrise. See Note B.
[4]	Interest expense for the three and nine months ended September 30, 2014 includes $4.7 million and $15.0 million, respectively, related to interest on a capital lease with an affiliate. See Note H.
[5]	Represents the cash distributions declared related to the period presented. See Note K.

Statements_of_Consolidated_Ope1

Statements of Consolidated Operations (Footnotes) (USD $)	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Operating and maintenance expense	$11,710,000	[1],[2]	$9,740,000	[1],[2]	$33,267,000	[1],[2]	$26,020,000	[1],[2]
Selling, general and administrative expenses	9,901,000	[1],[2]	7,188,000	[1],[2]	30,931,000	[1],[2]	21,299,000	[1],[2]
EQT and subsidiaries	'		'		'		'
Operating and maintenance expense	6,400,000		4,900,000		18,000,000		13,900,000
Selling, general and administrative expenses	7,900,000		6,600,000		23,700,000		19,000,000
AVC	'		'		'		'
Interest expense on capital lease	$4,700,000		'		$15,000,000		'
[1]	Operating and maintenance expense includes charges from EQT Corporation and its subsidiaries (collectively, EQT) of $6.4 million and $4.9 million for the three months ended September 30, 2014 and 2013, respectively, and $18.0 million and $13.9 million for the nine months ended September 30, 2014 and 2013, respectively. Selling, general and administrative expense includes charges from EQT of $7.9 million and $6.6 million for the three months ended September 30, 2014 and 2013, respectively, and $23.7 million and $19.0 million for the nine months ended September 30, 2014 and 2013, respectively. See Note D.
[2]	Financial statements for the nine months ended September 30, 2014 and the three months ended September 30, 2013 have been retrospectively recast to reflect the inclusion of the Jupiter natural gas gathering system (Jupiter). Financial statements for the nine months ended September 30, 2013 have been retrospectively recast to reflect the inclusion of Jupiter and Sunrise Pipeline, LLC (Sunrise). See Note B.

Statements_of_Consolidated_Cas

Statements of Consolidated Cash Flows (Unaudited) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013
Cash flows from operating activities:	'		'
Net income	$158,117	[1],[2]	$124,448	[1],[2]
Adjustments to reconcile net income to cash provided by operating activities:	'		'
Depreciation and amortization	26,742	[1],[2]	19,323	[1],[2]
Deferred income taxes	428	[1]	4,620	[1]
Other income	-1,634	[1]	-845	[1]
Non-cash long-term compensation expense	2,584	[1]	772	[1]
Non-cash adjustments	0	[1]	-680	[1]
Changes in other assets and liabilities:	'		'
Accounts receivable	-4,241	[1]	-983	[1]
Accounts payable	15,296	[1]	-9,450	[1]
Due to/from EQT affiliates	-9,788	[1]	10,464	[1]
Other assets and liabilities	1,477	[1]	1,111	[1]
Net cash provided by operating activities	188,981	[1]	148,780	[1]
Cash flows from investing activities:	'		'
Capital expenditures	-143,934	[1]	-76,173	[1]
Jupiter Acquisition – net assets from EQT	-168,198	[1]	0	[1]
Net cash used in investing activities	-312,132	[1]	-76,173	[1]
Cash flows from financing activities:	'		'
Proceeds from the issuance of common units, net of offering costs	902,467	[1]	529,442	[1]
Jupiter Acquisition – purchase price in excess of net assets from EQT	-952,802	[1]	0	[1]
Proceeds from short-term loans	450,000	[1]	0	[1]
Payments of short-term loans	-450,000	[1]	0	[1]
Proceeds from the issuance of long-term debt	500,000	[1]	0	[1]
Discount, debt issuance costs and credit facility origination fees	-9,634	[1]	0	[1]
Sunrise Merger payment	-110,000	[1]	-507,500	[1]
Distributions paid to unitholders	-82,089	[1]	-44,993	[1]
Capital contributions	382	[1]	4,241	[1]
Partners’ investments and net change in parent advances	13,905	[1]	-41,419	[1]
Predecessor distributions paid to EQT	0	[1]	-31,390	[1]
Capital lease principal payments	-2,216	[1]	0	[1]
Net cash provided by (used in) financing activities	260,013	[1]	-91,619	[1]
Net change in cash and cash equivalents	136,862	[1]	-19,012	[1]
Cash and cash equivalents at beginning of period	18,363	[1],[3]	50,041	[1]
Cash and cash equivalents at end of period	155,225	[1],[3]	31,029	[1]
Cash paid during the period for:	'		'
Interest paid	17,581	[1]	714	[1]
Non-cash activity during the period for:	'		'
Capital lease asset/obligation	7,231	[1]	0	[1]
Elimination of net current and deferred tax liabilities	51,813	[1]	42,972	[1]
Limited partner and general partner units issued for acquisitions	$59,000	[1]	$32,500	[1]
[1]	Financial statements for the nine months ended September 30, 2014 have been retrospectively recast to reflect the inclusion of Jupiter. Financial statements for the nine months ended September 30, 2013 have been retrospectively recast to reflect the inclusion of Jupiter and Sunrise. See Note B.
[2]	Financial statements for the nine months ended September 30, 2014 and the three months ended September 30, 2013 have been retrospectively recast to reflect the inclusion of the Jupiter natural gas gathering system (Jupiter). Financial statements for the nine months ended September 30, 2013 have been retrospectively recast to reflect the inclusion of Jupiter and Sunrise Pipeline, LLC (Sunrise). See Note B.
[3]	Financial statements as of December 31, 2013 have been retrospectively recast to reflect the inclusion of Jupiter. See Note B.

Consolidated_Balance_Sheets_Un

Consolidated Balance Sheets (Unaudited) (USD $)	Sep. 30, 2014		Dec. 31, 2013
In Thousands, unless otherwise specified
Current assets:	'		'
Cash and cash equivalents	$155,225	[1],[2]	$18,363	[1],[2]
Accounts receivable (net of allowance for doubtful accounts of $197 as of September 30, 2014 and $152 as of December 31, 2013)	12,704	[2]	8,463	[2]
Accounts receivable – affiliate	30,671	[2]	23,620	[2]
Other current assets	841	[2]	1,033	[2]
Total current assets	199,441	[2]	51,479	[2]
Property, plant and equipment	1,333,855	[2]	1,163,683	[2]
Less: accumulated depreciation	-192,296	[2]	-168,740	[2]
Net property, plant and equipment	1,141,559	[2]	994,943	[2]
Regulatory and other long-term assets	17,284	[2]	17,550	[2]
Total assets	1,358,284	[2]	1,063,972	[2]
Current liabilities:	'		'
Accounts payable	28,372	[2]	8,634	[2]
Due to related party	10,739	[2]	25,621	[2]
Sunrise merger consideration payable to EQT	0	[2]	110,000	[2]
Accrued liabilities	25,411	[2]	13,613	[2]
Total current liabilities	64,522	[2]	157,868	[2]
Deferred income taxes, net	0	[2]	39,840	[2]
Long-term debt	492,512	[2]	0	[2]
Lease obligation	141,008	[2]	133,733	[2]
Other long-term liabilities	7,184	[2]	6,014	[2]
Total liabilities	705,226	[2]	337,455	[2]
Partners’ capital:	'		'
Predecessor equity	0	[2]	82,329	[2]
Common units (43,347,452 and 30,468,902 units issued and outstanding at September 30, 2014 and December 31, 2013, respectively)	1,622,798	[2]	818,431	[2]
Subordinated units (17,339,718 units issued and outstanding at September 30, 2014 and December 31, 2013)	-939,754	[2]	-175,996	[2]
General partner interest (1,238,514 and 975,686 units issued and outstanding at September 30, 2014 and December 31, 2013, respectively)	-29,986	[2]	1,753	[2]
Total partners’ capital	653,058	[1],[2]	726,517	[1],[2]
Total liabilities and partners’ capital	$1,358,284	[2]	$1,063,972	[2]
[1]	Financial statements for the nine months ended September 30, 2014 have been retrospectively recast to reflect the inclusion of Jupiter. Financial statements for the nine months ended September 30, 2013 have been retrospectively recast to reflect the inclusion of Jupiter and Sunrise. See Note B.
[2]	Financial statements as of December 31, 2013 have been retrospectively recast to reflect the inclusion of Jupiter. See Note B.

Consolidated_Balance_Sheets_Un1

Consolidated Balance Sheets (Unaudited) (Parenthetical) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, except Share data, unless otherwise specified
Statement of Financial Position [Abstract]	'	'
Accounts Receivable, for doubtful accounts (in dollars)	$197	$152
Common units issued	43,347,452	30,468,902
Common units outstanding	43,347,452	30,468,902
Subordinated units issued	17,339,718	17,339,718
Subordinated units outstanding	17,339,718	17,339,718
General partner interest, unit issued	1,238,514	975,686
General partner interest, unit outstanding	1,238,514	975,686

Consolidated_Statements_of_Par

Consolidated Statements of Partners' Capital (Unaudited) (USD $)		Total		Limited Partners Common	Limited Partners Subordinated	General Partner	Predecessor Equity
In Thousands, unless otherwise specified
Beginning Balance at Dec. 31, 2012	[1]	$754,652		$313,304	$153,664	$8,108	$279,576
Increase (Decrease) in Partners' Capital		'		'	'	'	'
Net income	[1]	124,448	[2]	39,994	31,106	1,726	51,622
Capital contribution	[1]	3,248		1,778	1,404	66	'
Equity-based compensation plans	[1]	772		772	'	'	'
Distributions to unitholders	[1]	-44,993		-24,672	-19,421	-900	'
Predecessor distributions paid to EQT	[1]	-31,390		'	'	'	-31,390
Partners’ investments and net change in parent advances	[1]	-41,419		'	'	'	-41,419
Proceeds from equity offering, net of offering costs	[1]	529,442		529,442	'	'	'
Elimination of net current and deferred tax liabilities	[1]	42,972		'	'	'	42,972
Sunrise and Jupiter Net assets from EQT	[1]	-215,544		'	'	'	-215,544
Issuance of units	[1]	32,500		20,845	'	11,655	'
Purchase price in excess of net assets from EQT	[1]	-324,456		-51,352	-258,555	-14,549	'
Ending Balance at Sep. 30, 2013	[1]	830,232		830,111	-91,802	6,106	85,817
Beginning Balance at Dec. 31, 2013	[1]	726,517	[3]	818,431	-175,996	1,753	82,329
Increase (Decrease) in Partners' Capital		'		'	'	'	'
Net income	[1]	158,117	[2]	88,903	40,008	9,055	20,151
Capital contribution	[1]	500		338	152	10	'
Equity-based compensation plans	[1]	2,828		2,828	'	'	'
Distributions to unitholders	[1]	-82,089		-51,487	-25,489	-5,113	'
Partners’ investments and net change in parent advances	[1]	13,905		'	'	'	13,905
Proceeds from equity offering, net of offering costs	[1]	902,467		902,467	'	'	'
Elimination of net current and deferred tax liabilities	[1]	51,813		'	'	'	51,813
Sunrise and Jupiter Net assets from EQT	[1]	-168,198		'	'	'	-168,198
Issuance of units	[1]	59,000		39,091	'	19,909	'
Purchase price in excess of net assets from EQT	[1]	-1,011,802		-177,773	-778,429	-55,600	'
Ending Balance at Sep. 30, 2014	[1]	$653,058	[3]	$1,622,798	($939,754)	($29,986)	$0
[1]	Financial statements for the nine months ended September 30, 2014 have been retrospectively recast to reflect the inclusion of Jupiter. Financial statements for the nine months ended September 30, 2013 have been retrospectively recast to reflect the inclusion of Jupiter and Sunrise. See Note B.
[2]	Financial statements for the nine months ended September 30, 2014 and the three months ended September 30, 2013 have been retrospectively recast to reflect the inclusion of the Jupiter natural gas gathering system (Jupiter). Financial statements for the nine months ended September 30, 2013 have been retrospectively recast to reflect the inclusion of Jupiter and Sunrise Pipeline, LLC (Sunrise). See Note B.
[3]	Financial statements as of December 31, 2013 have been retrospectively recast to reflect the inclusion of Jupiter. See Note B.

Financial_Statements

Financial Statements	9 Months Ended
	Sep. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Financial Statements	'
	Financial Statements
	Organization
	EQT Midstream Partners, LP (EQT Midstream Partners or the Partnership) is a growth-oriented Delaware limited partnership. EQT Midstream Services, LLC, a wholly owned subsidiary of EQT Corporation, is the Partnership’s general partner. References in these consolidated financial statements to EQT refer collectively to EQT Corporation and its consolidated subsidiaries.
	Limited Partner and General Partner Units
	The following table summarizes common, subordinated and general partner units issued January 1, 2013 through September 30, 2014.
		Limited Partner Units		General
		Common	Subordinated	Partner Units	Total
	Balance at January 1, 2013	17,339,718	17,339,718	707,744	35,387,180
	July 2013 equity offering	12,650,000	—	—	12,650,000
	Sunrise Merger consideration	479,184	—	267,942	747,126
	Balance at December 31, 2013	30,468,902	17,339,718	975,686	48,784,306
	May 2014 equity offering	12,362,500	—	—	12,362,500
	Jupiter Acquisition consideration	516,050	—	262,828	778,878
	Balance at September 30, 2014	43,347,452	17,339,718	1,238,514	61,925,684
	On May 7, 2014, the Partnership completed an underwritten public offering of 12,362,500 common units.  Net proceeds from the offering were used to finance the cash consideration paid to EQT in connection with the acquisition of the Jupiter natural gas gathering system (Jupiter) from EQT (Jupiter Acquisition). The Partnership received net proceeds of approximately $902 million from the offering after deducting the underwriters’ discount and offering expenses.
	As of September 30, 2014, EQT retained a 36.4% equity interest in the Partnership, which includes 3,959,952 common units, 17,339,718 subordinated units and 1,238,514 general partner units.
	Basis of Presentation
	The accompanying unaudited consolidated financial statements have been prepared in accordance with GAAP for interim financial information and with the requirements of Form 10-Q and Article 10 of Regulation S-X.  Accordingly, they do not include all of the information and footnotes required by GAAP for complete financial statements.  In the opinion of management, these unaudited consolidated financial statements include all adjustments (consisting of only normal recurring accruals, unless otherwise disclosed in this Form 10-Q) necessary for a fair presentation of the financial position of the Partnership as of September 30, 2014 and December 31, 2013, the results of its operations for the three and nine months ended September 30, 2014 and 2013 and its cash flows for the nine months ended September 30, 2014 and 2013. Certain previously reported amounts have been reclassified to conform to the current year presentation.
	The balance sheet at December 31, 2013 has been derived from the audited financial statements at that date but does not include all of the information and footnotes required by GAAP for complete financial statements.
	The Jupiter Acquisition and Sunrise Merger (as defined in Note B) were transactions between entities under common control; therefore, the Partnership recorded the assets and liabilities of Jupiter and Sunrise at their carrying amounts to EQT on the date of the respective transactions. The difference between EQT’s net carrying amount and the total consideration paid to EQT was recorded as a capital transaction with EQT, which resulted in a reduction in partners’ capital.  The Partnership recast its consolidated financial statements to retrospectively reflect the Jupiter Acquisition and Sunrise Merger as if the assets and liabilities were owned for all periods presented; however, the consolidated financial statements are not necessarily indicative of the results of operations that would have occurred if the Partnership had owned the assets during the periods reported.
	Due to the seasonal nature of the Partnership’s utility customer contracts, the interim statements for the three and nine months ended September 30, 2014 are not necessarily indicative of the results that may be expected for the year ending December 31, 2014.
	For further information, refer to the consolidated financial statements and footnotes thereto for the year ended December 31, 2013 included in the Partnership’s Current Report on Form 8-K, as filed on June 26, 2014, as well as “Management’s Discussion and Analysis of Financial Condition and Results of Operations” contained therein.
	Recently Issued Accounting Standards
	In May 2014, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) No. 2014-09, Revenue from Contracts with Customers.  The standard requires an entity to recognize revenue in a manner that depicts the transfer of goods or services to customers at an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services.  ASU 2014-09 will replace most of the existing revenue recognition requirements in GAAP when it becomes effective.  The guidance in ASU 2014-09 is effective for public entities for annual reporting periods beginning after December 15, 2016, including interim periods therein.  Early adoption is not permitted.  The Partnership is currently evaluating the method of adoption and impact this standard will have on its financial statements and related disclosures.

Jupiter_Acquisition_and_Sunris

Jupiter Acquisition and Sunrise Merger	9 Months Ended
	Sep. 30, 2014
Business Combinations [Abstract]	'
Jupiter Acquisition and Sunrise Merger	'
	Jupiter Acquisition and Sunrise Merger
	On April 30, 2014, the Partnership, its general partner, EQM Gathering Opco, LLC (EQM Gathering), a wholly owned subsidiary of the Partnership, and EQT Gathering, LLC (EQT Gathering), a wholly owned subsidiary of EQT entered into a contribution agreement (Contribution Agreement) pursuant to which, on May 7, 2014, EQT Gathering contributed to EQM Gathering certain assets constituting the Jupiter natural gas gathering system.
	The aggregate consideration paid by the Partnership to EQT in connection with the Jupiter Acquisition was approximately $1,180 million, consisting of a $1,121 million cash payment and issuance of 516,050 common units and 262,828 general partner units of the Partnership. The cash portion of the purchase price was funded with the net proceeds from an equity offering of common units, as discussed in Note A, and borrowings under the Partnership’s credit facility.
	On July 15, 2013, the Partnership and Equitrans, L.P. (Equitrans) entered into an Agreement and Plan of Merger with EQT and Sunrise Pipeline, LLC (Sunrise), a wholly owned subsidiary of EQT and the owner of the Sunrise Pipeline. Effective July 22, 2013, Sunrise merged with and into Equitrans, with Equitrans continuing as the surviving company (Sunrise Merger).  Upon closing, the Partnership paid EQT consideration of $540 million, consisting of a $507.5 million cash payment and issuance of 479,184 common units and 267,942 general partner units of the Partnership. Prior to the Sunrise Merger, Equitrans entered into a precedent agreement with a third party for firm transportation service on the Sunrise Pipeline over a twenty year term (the Precedent Agreement).  Pursuant to the Agreement and Plan of Merger, following the effectiveness of the transportation agreement contemplated by the Precedent Agreement in December 2013, the Partnership paid additional consideration of $110 million to EQT in January 2014.
	The Jupiter Acquisition and Sunrise Merger were transactions between entities under common control; therefore, the Partnership recast its consolidated financial statements to retrospectively reflect these transactions as further discussed in Note A. Prior to the Sunrise Merger, the Partnership operated the Sunrise Pipeline as part of its transmission and storage system under a lease agreement with EQT. The lease was a capital lease under GAAP; therefore, prior to the merger, revenues and expenses associated with Sunrise were included in the Partnership’s historical consolidated financial statements and the Sunrise Pipeline was depreciated over the lease term of 15 years. Effective as of the closing of the Sunrise Merger on July 22, 2013, the lease agreement was terminated. Because the Sunrise Merger was a transaction between entities under common control, the Partnership has recast its financial statements to retrospectively reflect the merger. This included recasting depreciation expense recognized for the periods prior to the merger to reflect the pipeline’s useful life of 40 years. The decrease in depreciation expense and interest expense associated with the capital lease increased previously reported net income for the first six months of 2013.

Financial_Information_by_Busin

Financial Information by Business Segment	9 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Financial Information by Business Segment	'
	Financial Information by Business Segment
	Operating segments are revenue-producing components of the enterprise for which separate financial information is produced internally and is subject to evaluation by the chief operating decision maker in deciding how to allocate resources.
	The Partnership reports its operations in two segments, which reflect its lines of business. Transmission and storage includes the Partnership’s FERC-regulated interstate pipeline and storage business. Gathering includes Jupiter and the FERC-regulated low pressure gathering system. The operating segments are evaluated on their contribution to the Partnership’s results based on operating income.
	All of the Partnership’s operating revenues, income from operations and assets are generated or located in the United States.
		Three Months Ended September 30,				Nine Months Ended September 30,
		2014		2013		2014		2013
		(Thousands)
	Revenues from external customers:
	Transmission and storage	$	62,436	$	42,858	$	180,878	$	125,883
	Gathering	33,408		34,618		99,945		96,816
	Total	$	95,844	$	77,476	$	280,823	$	222,699
	Operating income:
	Transmission and storage	$	42,515	$	30,435	$	126,534	$	90,562
	Gathering	21,872		23,489		63,349		65,495
	Total operating income	$	64,387	$	53,924	$	189,883	$	156,057
	Reconciliation of operating income to net income:
	Other income, net	806		319		1,634		845
	Interest expense, net	8,660		196		20,944		613
	Income tax expense	—		9,993		12,456		31,841
	Net income	$	56,533	$	44,054	$	158,117	$	124,448
		30-Sep-14		31-Dec-13
		(Thousands)
	Segment assets:
	Transmission and storage	$	892,361	$	807,287
	Gathering	307,843		238,322
	Total operating segments	$	1,200,204	$	1,045,609
	Headquarters, including cash	158,080		18,363
	Total assets	$	1,358,284	$	1,063,972
		Three Months Ended September 30,				Nine Months Ended September 30,
		2014		2013		2014		2013
		(Thousands)
	Depreciation and amortization:
	Transmission and storage	$	7,195	$	4,542	$	19,676	$	13,295
	Gathering	2,651		2,082		7,066		6,028
	Total	$	9,846	$	6,624	$	26,742	$	19,323
	Expenditures for segment assets:
	Transmission and storage	$	39,826	$	27,280	$	78,907	$	50,503
	Gathering	28,682		6,283		69,713		24,617
	Total (1)	$	68,508	$	33,563	$	148,620	$	75,120
	(1)  The Partnership accrues capital expenditures when work has been completed but the associated bills have not yet been paid.  These accrued amounts are excluded from capital expenditures on the consolidated statements of cash flows until they are paid in a subsequent period. Accrued capital expenditures were $7.6 million, $6.0 million and $3.2 million at September 30, 2014, June 30, 2014 and December 31, 2013, respectively.  Accrued capital expenditures were $3.7 million, $3.7 million and $4.8 million at September 30, 2013, June 30, 2013 and December 31, 2012, respectively.

RelatedParty_Transactions

Related-Party Transactions	9 Months Ended
	Sep. 30, 2014
Related Party Transactions [Abstract]	'
Related-Party Transactions	'
	Related-Party Transactions
	In the ordinary course of business, the Partnership has transactions with EQT affiliated companies. The Partnership has various contracts with EQT affiliates including, but not limited to, transportation service and precedent agreements, storage agreements and gas gathering agreements.
	The Partnership has various agreements with EQT. Pursuant to an omnibus agreement, EQT performs centralized corporate, general and administrative services for the Partnership, such as legal, corporate recordkeeping, planning, budgeting, regulatory, accounting, billing, business development, treasury, insurance administration and claims processing, risk management, health, safety and environmental, information technology, human resources, investor relations, cash management and banking, payroll, internal audit, taxes and engineering. In exchange, the Partnership reimburses EQT for the expenses incurred in providing these services, except for any expenses associated with EQT’s long-term incentive programs as these are not expenses of the Partnership subsequent to the initial public offering (IPO) under the Partnership’s omnibus agreement.  The Partnership’s general partner established its own long-term incentive compensation plan in 2012. The omnibus agreement further requires that the Partnership reimburse EQT for the Partnership’s allocable portion of the premiums on any insurance policies covering the Partnership’s assets. EQT does not record any profit or margin for the administrative and operational services charged to the Partnership.
	Pursuant to an operation and management services agreement, EQT Gathering provides the Partnership’s pipelines and storage facilities with certain operational and management services.  The Partnership reimburses EQT Gathering for such services pursuant to the terms of the omnibus agreement.  The expenses for which the Partnership reimburses EQT and its subsidiaries may not necessarily reflect the actual expenses that the Partnership would incur on a stand-alone basis and the Partnership is unable to estimate what those expenses would be on a stand-alone basis.

Income_Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2014
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	Income Taxes
	As a result of its limited partnership structure, the Partnership is not subject to federal and state income taxes. For federal and state income tax purposes, all income, expenses, gains, losses and tax credits generated by the Partnership flow through to the unitholders; accordingly, the Partnership does not record a provision for income taxes. As discussed in Note B, the Partnership completed the Sunrise Merger on July 22, 2013 and the Jupiter Acquisition on May 7, 2014, each of which was a transaction between entities under common control. Prior to these transactions, the income from Sunrise and Jupiter was included in EQT’s consolidated federal tax return; therefore, the Sunrise and Jupiter financial statements included U.S. federal and state income tax.  The income tax effects associated with the operations of Sunrise and Jupiter prior to the Sunrise Merger and the Jupiter Acquisition are reflected in the Partnership’s consolidated financial statements for those periods.

Debt

Debt	9 Months Ended
	Sep. 30, 2014
Long-term Debt, Current and Noncurrent [Abstract]	'
Debt	'
	Debt
	In February 2014, the Partnership amended its credit facility to increase the borrowing capacity to $750 million. The amended credit facility will expire in February 2019. The credit facility is available to fund working capital requirements and capital expenditures, to purchase assets, to pay distributions, to repurchase units and for general partnership purposes.
	As of September 30, 2014 and December 31, 2013, there were no amounts outstanding under the credit facility. The maximum amount of the Partnership’s outstanding short-term loans at any time during the three and nine months ended September 30, 2014 was $330 million and $450 million, respectively. The average daily balance of short-term loans outstanding was approximately $133 million and $159 million for the three and nine months ended September 30, 2014, respectively. Interest was incurred on the loans at a weighted average annual interest rate of 1.66% and 1.67% for the three and nine months ended September 30, 2014, respectively.
	During the third quarter of 2014, the Partnership issued 4.00% Senior Notes due August 1, 2024 in the aggregate principal amount of $500 million (the 4.00% Senior Notes). Net proceeds from the offering of $492.4 million, inclusive of a discount of $2.9 million and debt issuance costs of $4.7 million, were used to repay the outstanding borrowings under the Partnership’s credit facility and for general partnership purposes. The payment obligations under the 4.00% Senior Notes are unconditionally guaranteed, jointly and severally, on an unsecured basis, by each of the Partnership’s existing and future subsidiaries that guarantees the Partnership’s credit facility (other than EQT Midstream Finance Corporation), which entities are referred to as "the Subsidiary Guarantors." The 4.00% Senior Notes contain covenants that limit the Partnership’s ability to, among other things, incur certain liens securing indebtedness, engage in certain sale and leaseback transactions, and enter into certain consolidations, mergers, conveyances, transfers or leases of all or substantially all of the Partnership’s assets.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Value Measurements	'
	Fair Value Measurements
	The Partnership has categorized its assets and liabilities recorded at fair value into a three-level fair value hierarchy, based on the priority of the inputs to the valuation technique.  The fair value hierarchy gives the highest priority to quoted prices in active markets for identical assets and liabilities (Level 1) and the lowest priority to unobservable inputs (Level 3).
	The carrying value of cash and cash equivalents, accounts receivable, amounts due to/from related parties and accounts payable approximate fair value due to the short maturity of the instruments; these are considered Level 1 fair values. The carrying value of short-term loans under the Partnership's credit facility approximates fair value as the interest rates are based on prevailing market rates; this is considered a Level 1 fair value. As the Partnership’s long-term debt is not actively traded, the fair value of the debt is a Level 2 fair value measurement which is estimated using a standard industry income approach model which utilizes a discount rate based on market rates for debt with similar remaining time to maturity and credit risk.  As of September 30, 2014, the estimated fair value of long-term debt was approximately $496 million.

Lease_Obligations

Lease Obligations	9 Months Ended
	Sep. 30, 2014
Leases [Abstract]	'
Lease Obligations	'
	Lease Obligations
	On December 17, 2013, the Partnership entered into a lease with EQT for the Allegheny Valley Connector (AVC) facilities. Under the lease, the Partnership operates the AVC facilities as part of its transmission and storage system under the rates, terms and conditions of its FERC-approved tariff.  The AVC facilities are strategically located to connect Marcellus Shale supply and demand and include an approximately 200 mile pipeline that interconnects with the Partnership’s transmission and storage system. Additionally, the AVC facilities provide 0.45 BBtu per day of additional firm capacity to the Partnership’s system and are supported by 4 associated natural gas storage reservoirs with approximately 260 MMcf per day of peak withdrawal capability and 15 Bcf of working gas capacity. Of the total 15 Bcf of working gas capacity, the Partnership leases and operates 13 Bcf of working gas capacity. The lease payment due each month is the lesser of the following alternatives: (1) a revenue-based payment reflecting the revenues generated by the operation of the AVC facilities minus the actual costs of operating the AVC facilities and (2) a payment based on depreciation expense and pre-tax return on invested capital for the AVC facilities. As a result, the payments to be made under the AVC lease will be variable.
	The AVC lease is a capital lease under GAAP. The gross capital lease assets and obligations recorded in 2013 were approximately $134.4 million. The Partnership expects modernization capital expenditures will be incurred by EQT to upgrade the AVC facilities. As the capital expenditures are incurred, the capital lease asset and obligations will increase.
	For the three and nine months ended September 30, 2014, interest expense of $4.7 million and $15.0 million, respectively, and depreciation expense of $1.5 million and $4.2 million, respectively, were recorded related to the capital lease. At September 30, 2014, accumulated depreciation was $4.7 million, net capital lease assets were $136.9 million and capital lease obligations were $141.3 million. At September 30, 2014 and December 31, 2013, the current portion of capital lease obligation was $0.3 million and $0.7 million, respectively, and accrued interest related to the lease obligation was $1.4 million and $0.8 million, respectively, all of which are included in accrued liabilities on the consolidated balance sheets for both periods.

Net_Income_per_Limited_Partner

Net Income per Limited Partner Unit	9 Months Ended
	Sep. 30, 2014
Net Income per Limited Partner Unit	'
Net Income per Limited Partner Unit	'
	Net Income per Limited Partner Unit
	The Partnership’s net income is allocated to the general partner and limited partners, including the subordinated unitholder, in accordance with their respective ownership percentages, and when applicable, giving effect to incentive distributions allocable to the general partner. The allocation of undistributed earnings, or net income in excess of distributions, to the incentive distribution rights is limited to available cash (as defined by the Partnership’s partnership agreement) for the period. Net income allocated to the general partner includes amounts attributed to incentive distributions, as applicable. The Partnership’s net income allocable to the limited partners is allocated between common and subordinated unitholders by applying the provisions of the Partnership’s partnership agreement that govern actual cash distributions as if all earnings for the period had been distributed. Any common units issued during the period are included on a monthly weighted-average basis for the periods in which they were outstanding. The phantom units granted to the independent directors of the Partnership’s general partner will be paid in common units on a director’s termination of service on the general partner’s Board of Directors. As there are no remaining service, performance or market conditions related to these awards, 11,654 and 11,323 phantom unit awards were included in the calculation of basic weighted average limited partner units outstanding for the three and nine months ended September 30, 2014, respectively.
	Diluted net income per limited partner unit reflects the potential dilution that could occur if securities or agreements to issue common units, such as awards under the long-term incentive plan, were exercised, settled or converted into common units.  When it is determined that potential common units resulting from an award subject to performance or market conditions should be included in the diluted net income per limited partner unit calculation, the impact is reflected by applying the treasury stock method. Potentially dilutive securities, consisting of performance awards, included in the calculation of diluted weighted average limited partner units outstanding totaled 128,588 and 112,281 for the three months ended September 30, 2014 and 2013, respectively, and 125,124 and 113,297 for the nine months ended September 30, 2014 and 2013, respectively. The 2014 EQM Value Driver Awards granted in the first quarter of 2014 were not included in potentially dilutive securities because the performance condition has not yet been met.
	The following table presents the Partnership’s calculation of net income per limited partner unit for common and subordinated limited partner units. Net income attributable to Sunrise for the period prior to July 22, 2013 and to Jupiter for the period prior to May 7, 2014 was not allocated to the limited partners for purposes of calculating net income per limited partner unit.
		Three Months Ended September 30,						Nine Months Ended September 30,
		2014			2013			2014			2013
		(Thousands, except per unit data)
	Net income	$	56,533		$	44,054		$	158,117		$	124,448
	Less:
	Pre-acquisition net income allocated to parent	—			(16,338		)	(20,151		)	(51,622		)
	General partner interest in net income – 2%	(1,130		)	(554		)	(2,759		)	(1,525		)
	General partner interest in net income attributable to incentive distribution rights	(3,410		)	(201		)	(6,296		)	(201		)
	Limited partner interest in net income	$	51,993		$	26,961		$	128,911		$	71,100
	Net income allocable to common units - basic	$	37,138		$	17,011		$	88,903		$	39,994
	Net income allocable to subordinated units - basic	14,855			9,950			40,008			31,106
	Limited partner interest in net income - basic	$	51,993		$	26,961		$	128,911		$	71,100
	Net income allocable to common units – diluted	$	37,150		$	17,018		$	88,932		$	40,012
	Net income allocable to subordinated units – diluted	14,843			9,943			39,979			31,088
	Limited partner interest in net income – diluted	$	51,993		$	26,961		$	128,911		$	71,100
	Weighted average limited partner units outstanding – basic
	Common units	43,359			27,186			36,919			21,278
	Subordinated units	17,340			17,340			17,340			17,340
	Total	60,699			44,526			54,259			38,618
	Weighted average limited partner units outstanding – diluted
	Common units	43,487			27,299			37,044			21,391
	Subordinated units	17,340			17,340			17,340			17,340
	Total	60,827			44,639			54,384			38,731
	Net income per limited partner unit – basic
	Common units	$	0.86		$	0.63		$	2.41		$	1.88
	Subordinated units	0.86			0.57			2.31			1.79
	Total	$	0.86		$	0.61		$	2.38		$	1.84
	Net income per limited partner unit – diluted
	Common units	$	0.85		$	0.62		$	2.4		$	1.87
	Subordinated units	0.86			0.57			2.31			1.79
	Total	$	0.85		$	0.6		$	2.37		$	1.84

Subsidiary_Guarantors

Subsidiary Guarantors	9 Months Ended
	Sep. 30, 2014
Subsidiary Guarantors	'
Subsidiary Guarantors	'
	Subsidiary Guarantors
	The Partnership filed a registration statement on Form S-3 with the SEC on July 1, 2013, as amended by a post-effective amendment filed with the SEC on June 26, 2014.  The purpose of the Form S-3 was to register, among other securities, debt securities. Certain subsidiaries of the Partnership are co-registrants with the Partnership (Subsidiary Guarantors), and the registration statement registered guarantees of debt securities by one or more of the Subsidiary Guarantors (other than EQT Midstream Finance Corporation, a 100% owned subsidiary of the Partnership whose primary purpose is to act as co-issuer of debt securities). The Subsidiary Guarantors are 100% owned by the Partnership and any guarantees by the Subsidiary Guarantors will be full and unconditional. Subsidiaries of the Partnership other than the Subsidiary Guarantors and EQT Midstream Finance Corporation, if any, are minor. As further discussed in Note F, during the third quarter of 2014 the Partnership issued 4.00% Senior Notes. The payment obligations of the 4.00% Senior Notes are unconditionally guaranteed, jointly and severally, on an unsecured basis, by each of the Partnership's existing and future subsidiaries that guarantee the Partnership's credit facility. Initially, the 4.00% Senior Notes are guaranteed by all of the Partnership's subsidiaries other than EQT Midstream Finance Corporation. The guarantees issued in connection with the 4.00% Senior Notes are full and unconditional and joint and several, subject to certain automatic customary releases in accordance with the applicable indenture.
	There are no significant restrictions upon the ability of the Subsidiary Guarantors to distribute funds to the Partnership by dividend or loan. None of the assets of the Partnership or the Subsidiary Guarantors represent restricted net assets pursuant to Rule 4-08(e)(3) of Regulation S-X under the Securities Act of 1933, as amended.

Subsequent_Events

Subsequent Events	9 Months Ended
	Sep. 30, 2014
Subsequent Events [Abstract]	'
Subsequent Events	'
	Subsequent Events
	On October 21, 2014, the Board of Directors of the Partnership’s general partner declared a cash distribution to the Partnership’s unitholders for the third quarter of 2014 of $0.55 per common and subordinated unit, $0.8 million to the general partner related to its 2% general partner interest and $3.4 million to the general partner related to its incentive distribution rights. The cash distribution will be paid on November 14, 2014 to unitholders of record at the close of business on November 4, 2014.

Financial_Statements_Tables

Financial Statements (Tables)	9 Months Ended
	Sep. 30, 2014
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Summary of common, subordinated and general partner units issued	'
	The following table summarizes common, subordinated and general partner units issued January 1, 2013 through September 30, 2014.
		Limited Partner Units		General
		Common	Subordinated	Partner Units	Total
	Balance at January 1, 2013	17,339,718	17,339,718	707,744	35,387,180
	July 2013 equity offering	12,650,000	—	—	12,650,000
	Sunrise Merger consideration	479,184	—	267,942	747,126
	Balance at December 31, 2013	30,468,902	17,339,718	975,686	48,784,306
	May 2014 equity offering	12,362,500	—	—	12,362,500
	Jupiter Acquisition consideration	516,050	—	262,828	778,878
	Balance at September 30, 2014	43,347,452	17,339,718	1,238,514	61,925,684

Financial_Information_by_Busin1

Financial Information by Business Segment (Tables)	9 Months Ended
	Sep. 30, 2014
Segment Reporting [Abstract]	'
Schedule of revenue from external customers and operating income and reconciliation to net income	'
	All of the Partnership’s operating revenues, income from operations and assets are generated or located in the United States.
		Three Months Ended September 30,				Nine Months Ended September 30,
		2014		2013		2014		2013
		(Thousands)
	Revenues from external customers:
	Transmission and storage	$	62,436	$	42,858	$	180,878	$	125,883
	Gathering	33,408		34,618		99,945		96,816
	Total	$	95,844	$	77,476	$	280,823	$	222,699
	Operating income:
	Transmission and storage	$	42,515	$	30,435	$	126,534	$	90,562
	Gathering	21,872		23,489		63,349		65,495
	Total operating income	$	64,387	$	53,924	$	189,883	$	156,057
	Reconciliation of operating income to net income:
	Other income, net	806		319		1,634		845
	Interest expense, net	8,660		196		20,944		613
	Income tax expense	—		9,993		12,456		31,841
	Net income	$	56,533	$	44,054	$	158,117	$	124,448
Schedule of segment assets	'
		30-Sep-14		31-Dec-13
		(Thousands)
	Segment assets:
	Transmission and storage	$	892,361	$	807,287
	Gathering	307,843		238,322
	Total operating segments	$	1,200,204	$	1,045,609
	Headquarters, including cash	158,080		18,363
	Total assets	$	1,358,284	$	1,063,972
Schedule of depreciation, depletion and amortization and expenditures for segment assets	'
		Three Months Ended September 30,				Nine Months Ended September 30,
		2014		2013		2014		2013
		(Thousands)
	Depreciation and amortization:
	Transmission and storage	$	7,195	$	4,542	$	19,676	$	13,295
	Gathering	2,651		2,082		7,066		6,028
	Total	$	9,846	$	6,624	$	26,742	$	19,323
	Expenditures for segment assets:
	Transmission and storage	$	39,826	$	27,280	$	78,907	$	50,503
	Gathering	28,682		6,283		69,713		24,617
	Total (1)	$	68,508	$	33,563	$	148,620	$	75,120
	(1)  The Partnership accrues capital expenditures when work has been completed but the associated bills have not yet been paid.  These accrued amounts are excluded from capital expenditures on the consolidated statements of cash flows until they are paid in a subsequent period. Accrued capital expenditures were $7.6 million, $6.0 million and $3.2 million at September 30, 2014, June 30, 2014 and December 31, 2013, respectively.  Accrued capital expenditures were $3.7 million, $3.7 million and $4.8 million at September 30, 2013, June 30, 2013 and December 31, 2012, respectively.

Net_Income_per_Limited_Partner1

Net Income per Limited Partner Unit (Tables)	9 Months Ended
	Sep. 30, 2014
Net Income per Limited Partner Unit	'
Schedule of partnership's calculation of net income per limited partner unit for common and subordinated limited partner units	'
	Net income attributable to Sunrise for the period prior to July 22, 2013 and to Jupiter for the period prior to May 7, 2014 was not allocated to the limited partners for purposes of calculating net income per limited partner unit.
		Three Months Ended September 30,						Nine Months Ended September 30,
		2014			2013			2014			2013
		(Thousands, except per unit data)
	Net income	$	56,533		$	44,054		$	158,117		$	124,448
	Less:
	Pre-acquisition net income allocated to parent	—			(16,338		)	(20,151		)	(51,622		)
	General partner interest in net income – 2%	(1,130		)	(554		)	(2,759		)	(1,525		)
	General partner interest in net income attributable to incentive distribution rights	(3,410		)	(201		)	(6,296		)	(201		)
	Limited partner interest in net income	$	51,993		$	26,961		$	128,911		$	71,100
	Net income allocable to common units - basic	$	37,138		$	17,011		$	88,903		$	39,994
	Net income allocable to subordinated units - basic	14,855			9,950			40,008			31,106
	Limited partner interest in net income - basic	$	51,993		$	26,961		$	128,911		$	71,100
	Net income allocable to common units – diluted	$	37,150		$	17,018		$	88,932		$	40,012
	Net income allocable to subordinated units – diluted	14,843			9,943			39,979			31,088
	Limited partner interest in net income – diluted	$	51,993		$	26,961		$	128,911		$	71,100
	Weighted average limited partner units outstanding – basic
	Common units	43,359			27,186			36,919			21,278
	Subordinated units	17,340			17,340			17,340			17,340
	Total	60,699			44,526			54,259			38,618
	Weighted average limited partner units outstanding – diluted
	Common units	43,487			27,299			37,044			21,391
	Subordinated units	17,340			17,340			17,340			17,340
	Total	60,827			44,639			54,384			38,731
	Net income per limited partner unit – basic
	Common units	$	0.86		$	0.63		$	2.41		$	1.88
	Subordinated units	0.86			0.57			2.31			1.79
	Total	$	0.86		$	0.61		$	2.38		$	1.84
	Net income per limited partner unit – diluted
	Common units	$	0.85		$	0.62		$	2.4		$	1.87
	Subordinated units	0.86			0.57			2.31			1.79
	Total	$	0.85		$	0.6		$	2.37		$	1.84

Financial_Statements_Details

Financial Statements (Details) (USD $)

0 Months Ended

9 Months Ended

12 Months Ended

12 Months Ended

9 Months Ended

0 Months Ended

9 Months Ended

12 Months Ended

9 Months Ended

12 Months Ended

9 Months Ended

In Thousands, except Share data, unless otherwise specified

7-May-14

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2013

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

7-May-14

Sep. 30, 2014

Dec. 31, 2013

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2014

Dec. 31, 2013

Dec. 31, 2012

Sep. 30, 2014

Dec. 31, 2013

Dec. 31, 2012

Dec. 31, 2013

Sep. 30, 2014

EQT

Sunrise

Jupiter

Limited Partners Common

Limited Partners Common

Limited Partners Common

Limited Partners Common

Limited Partners Common

Limited Partners Subordinated

Limited Partners Subordinated

Limited Partners Subordinated

General Partner

General Partner

General Partner

General Partner

General Partner

Sunrise

Jupiter

Sunrise

Jupiter

Increase (Decrease) in Partners' Capital

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Beginning Balance (in shares)

'

48,784,306

35,387,180

35,387,180

'

'

'

'

30,468,902

17,339,718

'

'

17,339,718

17,339,718

17,339,718

1,238,514

975,686

707,744

'

'

Issued in connection with public offering (in shares)

12,362,500

12,362,500

'

12,650,000

'

'

'

'

12,362,500

12,650,000

'

'

'

'

'

'

'

'

'

'

Merger/acquisition consideration (in shares)

'

'

'

'

'

747,126

778,878

'

'

'

479,184

516,050

'

'

'

'

'

'

267,942

262,828

Ending Balance (in shares)

'

61,925,684

'

48,784,306

'

'

'

'

43,347,452

30,468,902

'

'

17,339,718

17,339,718

17,339,718

1,238,514

975,686

707,744

'

'

Proceeds from the issuance of common units, net of offering costs

'

$902,467

[1]

$529,442

[1]

'

'

'

'

$902,000

'

'

'

'

'

'

'

'

'

'

'

'

Additional disclosures

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Equity interest retained by parent

'

'

'

'

36.40%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Common units held by parent (in shares)

'

'

'

'

3,959,952

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Subordinated units held by parent (in shares)

'

'

'

'

17,339,718

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

General partner units held by parent (in shares)

'

'

'

'

1,238,514

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

[1]

Financial statements for the nine months ended September 30, 2014 have been retrospectively recast to reflect the inclusion of Jupiter. Financial statements for the nine months ended September 30, 2013 have been retrospectively recast to reflect the inclusion of Jupiter and Sunrise. See Note B.

Jupiter_Acquisition_and_Sunris1

Jupiter Acquisition and Sunrise Merger (Details) (USD $)

9 Months Ended

9 Months Ended

0 Months Ended

0 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Dec. 31, 2013

Sep. 30, 2014

Sep. 30, 2014

7-May-14

7-May-14

Jul. 22, 2014

Jul. 22, 2013

Dec. 31, 2013

Pipelines

Sunrise

EQT

EQT

EQT

EQT

EQT

Jupiter

Jupiter

Sunrise

Sunrise

Sunrise

Acquisition and Merger

'

'

'

'

'

'

'

'

'

'

Consideration paid

'

'

'

'

'

$1,180,000,000

'

$540,000,000

'

'

Cash payment

110,000,000

[1]

507,500,000

[1]

'

'

'

1,121,000,000

'

'

507,500,000

'

Common units issued

43,347,452

'

30,468,902

'

'

'

516,050

'

479,184

'

General partner units issued

1,238,514

'

975,686

'

'

'

262,828

'

267,942

'

Term of the transportation precedent agreement

'

'

'

'

'20 years

'

'

'

'

'

Additional cash consideration related to the transportation precedent agreement

'

'

'

'

'

'

'

'

'

$110,000,000

Life of the lease

'

'

'

'15 years

'

'

'

'

'

'

Estimated service life

'

'

'

'40 years

'

'

'

'

'

'

[1]

Financial statements for the nine months ended September 30, 2014 have been retrospectively recast to reflect the inclusion of Jupiter. Financial statements for the nine months ended September 30, 2013 have been retrospectively recast to reflect the inclusion of Jupiter and Sunrise. See Note B.

Financial_Information_by_Busin2

Financial Information by Business Segment (Details) (USD $)

3 Months Ended

9 Months Ended

Sep. 30, 2014

Sep. 30, 2013

Sep. 30, 2014

Sep. 30, 2013

Jun. 30, 2014

Dec. 31, 2013

Jun. 30, 2013

Dec. 31, 2012

Segment

Segment Information

'

'

'

'

'

'

'

'

Number of operating segments

'

'

2

'

'

'

'

'

Revenues from external customers

$95,844,000

[1]

$77,476,000

[1]

$280,823,000

[1]

$222,699,000

[1]

'

'

'

'

Operating income

64,387,000

[1]

53,924,000

[1]

189,883,000

[1]

156,057,000

[1]

'

'

'

'

Other income, net

806,000

[1]

319,000

[1]

1,634,000

[1]

845,000

[1]

'

'

'

'

Interest expense, net

8,660,000

[1],[2]

196,000

[1],[2]

20,944,000

[1],[2]

613,000

[1],[2]

'

'

'

'

Income tax expense

0

[1]

9,993,000

[1]

12,456,000

[1]

31,841,000

[1]

'

'

'

'

Net income

56,533,000

[1]

44,054,000

[1]

158,117,000

[1],[3]

124,448,000

[1],[3]

'

'

'

'

Segment assets

1,358,284,000

[4]

'

1,358,284,000

[4]

'

'

1,063,972,000

[4]

'

'

Depreciation and amortization

9,846,000

[1]

6,624,000

[1]

26,742,000

[1],[3]

19,323,000

[1],[3]

'

'

'

'

Expenditures for segment assets

68,508,000

[5]

33,563,000

[5]

148,620,000

[5]

75,120,000

[5]

'

'

'

'

Accrued capital expenditures

7,600,000

3,700,000

7,600,000

3,700,000

6,000,000

3,200,000

3,700,000

4,800,000

Non-cash compensation costs capitalized

100,000

'

200,000

'

'

'

'

'

Operating Segment

'

'

'

'

'

'

'

'

Segment Information

'

'

'

'

'

'

'

'

Segment assets

1,200,204,000

'

1,200,204,000

'

'

1,045,609,000

'

'

Headquarters

'

'

'

'

'

'

'

'

Segment Information

'

'

'

'

'

'

'

'

Segment assets

158,080,000

'

158,080,000

'

'

18,363,000

'

'

Transmission and storage

'

'

'

'

'

'

'

'

Segment Information

'

'

'

'

'

'

'

'

Revenues from external customers

62,436,000

42,858,000

180,878,000

125,883,000

'

'

'

'

Operating income

42,515,000

30,435,000

126,534,000

90,562,000

'

'

'

'

Segment assets

892,361,000

'

892,361,000

'

'

807,287,000

'

'

Depreciation and amortization

7,195,000

4,542,000

19,676,000

13,295,000

'

'

'

'

Expenditures for segment assets

39,826,000

27,280,000

78,907,000

50,503,000

'

'

'

'

Gathering

'

'

'

'

'

'

'

'

Segment Information

'

'

'

'

'

'

'

'

Revenues from external customers

33,408,000

34,618,000

99,945,000

96,816,000

'

'

'

'

Operating income

21,872,000

23,489,000

63,349,000

65,495,000

'

'

'

'

Segment assets

307,843,000

'

307,843,000

'

'

238,322,000

'

'

Depreciation and amortization

2,651,000

2,082,000

7,066,000

6,028,000

'

'

'

'

Expenditures for segment assets

$28,682,000

$6,283,000

$69,713,000

$24,617,000

'

'

'

'

[1]

Financial statements for the nine months ended September 30, 2014 and the three months ended September 30, 2013 have been retrospectively recast to reflect the inclusion of the Jupiter natural gas gathering system (Jupiter). Financial statements for the nine months ended September 30, 2013 have been retrospectively recast to reflect the inclusion of Jupiter and Sunrise Pipeline, LLC (Sunrise). See Note B.

[2]

Interest expense for the three and nine months ended September 30, 2014 includes $4.7 million and $15.0 million, respectively, related to interest on a capital lease with an affiliate. See Note H.

[3]

Financial statements for the nine months ended September 30, 2014 have been retrospectively recast to reflect the inclusion of Jupiter. Financial statements for the nine months ended September 30, 2013 have been retrospectively recast to reflect the inclusion of Jupiter and Sunrise. See Note B.

[4]

Financial statements as of December 31, 2013 have been retrospectively recast to reflect the inclusion of Jupiter. See Note B.

[5]

The Partnership accrues capital expenditures when work has been completed but the associated bills have not yet been paid. These accrued amounts are excluded from capital expenditures on the consolidated statements of cash flows until they are paid in a subsequent period. Accrued capital expenditures were $7.6 million, $6.0 million and $3.2 million at September 30, 2014, June 30, 2014 and December 31, 2013, respectively. Accrued capital expenditures were $3.7 million, $3.7 million and $4.8 million at September 30, 2013, June 30, 2013 and December 31, 2012, respectively.

Debt_Details

Debt (Details) (USD $)	Feb. 28, 2014	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014
	Revolving Credit Facility	Short-term Loans	Short-term Loans	Senior Notes
				4.00% Senior Notes Maturing 2024
Long-term debt	'	'	'	'
Maximum borrowing capacity	$750,000,000	'	'	'
Maximum amount of outstanding short-term loans at any time during the period	'	330,000,000	450,000,000	'
Average daily balance of short-term loans outstanding	'	133,000,000	159,000,000	'
Line of Credit Facility, Interest Rate During Period	'	1.66%	1.67%	'
Interest rate	'	'	'	4.00%
Face amount	'	'	'	500,000,000
Proceeds from issuance of senior debt	'	'	'	492,400,000
Unamortized discount	'	'	'	2,900,000
Debt issuance cost	'	'	'	$4,700,000

Fair_Value_Measurements_Detail

Fair Value Measurements (Details) (USD $)	Sep. 30, 2014
In Millions, unless otherwise specified
Fair Value Disclosures [Abstract]	'
Fair value of long-term debt	$496

Lease_Obligations_Details

Lease Obligations (Details) (USD $)	0 Months Ended	3 Months Ended	9 Months Ended
In Millions, unless otherwise specified	Dec. 17, 2013	Sep. 30, 2014	Sep. 30, 2014	Dec. 31, 2013
	MMcf
	mi
	MMBTU
	natural_gas_storage_reservoir
Lease obligations	'	'	'	'
Working gas capacity of associated natural gas storage reservoirs (in Mcf)	15,000,000	'	'	'
Working gas capacity of associated natural gas storage reservoirs which the entity leases and operates (in Mcf)	13,000,000	'	'	'
AVC	'	'	'	'
Lease obligations	'	'	'	'
Length of pipeline (in miles)	200	'	'	'
Additional per day firm capacity provided to the system (in BBtu per day)	450	'	'	'
Number of associated natural gas storage reservoirs which supports pipeline system	4	'	'	'
Peak withdrawal capability per day of associated natural gas storage reservoirs (in MMcf per day)	260	'	'	'
Net capital lease assets	'	$136.90	$136.90	$134.40
Interest expense on capital lease	'	4.7	15	'
Depreciation expense	'	1.5	4.2	'
Accumulated depreciation	'	4.7	4.7	'
Capital lease obligations	'	141.3	141.3	'
Capital lease obligations, current	'	0.3	0.3	0.7
Accrued interest	'	$1.40	$1.40	$0.80

Net_Income_per_Limited_Partner2

Net Income per Limited Partner Unit (Details) (USD $)	3 Months Ended				9 Months Ended
In Thousands, except Share data, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Net Income per Limited Partner Unit	'		'		'		'
Total (in shares)	60,699,000	[1]	44,526,000	[1]	54,259,000	[1]	38,618,000	[1]
Partnership's calculation of net income per unit for common and subordinated limited partner units:	'		'		'		'
Net income	$56,533	[1]	$44,054	[1]	$158,117	[1],[2]	$124,448	[1],[2]
Less:	'		'		'		'
Pre-acquisition net income allocated to parent	0	[1]	-16,338	[1]	-20,151	[1]	-51,622	[1]
General partner interest in net income – 2%	-1,130		-554		-2,759		-1,525
General partner's ownership interest	2.00%		2.00%		2.00%		2.00%
General partner interest in net income attributable to incentive distribution rights	-3,410		-201		-6,296		-201
Limited partner interest in net income	51,993	[1]	26,961	[1]	128,911	[1]	71,100	[1]
Limited partner interest in net income - basic	51,993		26,961		128,911		71,100
Limited partner interest in net income - diluted	51,993		26,961		128,911		71,100
Weighted average limited partner units outstanding – basic	'		'		'		'
Total (in shares)	60,699,000	[1]	44,526,000	[1]	54,259,000	[1]	38,618,000	[1]
Weighted average limited partner units outstanding – diluted	'		'		'		'
Total (in shares)	60,827,000	[1]	44,639,000	[1]	54,384,000	[1]	38,731,000	[1]
Net income per limited partner unit – basic	'		'		'		'
Basic (in dollars per share)	$0.86	[1]	$0.61	[1]	$2.38	[1]	$1.84	[1]
Net income per limited partner unit – diluted	'		'		'		'
Diluted (in dollars per share)	$0.85	[1]	$0.60	[1]	$2.37	[1]	$1.84	[1]
Common Units	'		'		'		'
Net Income per Limited Partner Unit	'		'		'		'
Total (in shares)	43,359,000		27,186,000		36,919,000		21,278,000
Partnership's calculation of net income per unit for common and subordinated limited partner units:	'		'		'		'
Net income	'		'		88,903	[2]	39,994	[2]
Less:	'		'		'		'
Limited partner interest in net income - basic	37,138		17,011		88,903		39,994
Limited partner interest in net income - diluted	37,150		17,018		88,932		40,012
Weighted average limited partner units outstanding – basic	'		'		'		'
Total (in shares)	43,359,000		27,186,000		36,919,000		21,278,000
Weighted average limited partner units outstanding – diluted	'		'		'		'
Total (in shares)	43,487,000		27,299,000		37,044,000		21,391,000
Net income per limited partner unit – basic	'		'		'		'
Basic (in dollars per share)	$0.86		$0.63		$2.41		$1.88
Net income per limited partner unit – diluted	'		'		'		'
Diluted (in dollars per share)	$0.85		$0.62		$2.40		$1.87
Subordinated Units	'		'		'		'
Net Income per Limited Partner Unit	'		'		'		'
Total (in shares)	17,340,000		17,340,000		17,340,000		17,340,000
Partnership's calculation of net income per unit for common and subordinated limited partner units:	'		'		'		'
Net income	'		'		40,008	[2]	31,106	[2]
Less:	'		'		'		'
Limited partner interest in net income - basic	14,855		9,950		40,008		31,106
Limited partner interest in net income - diluted	$14,843		$9,943		$39,979		$31,088
Weighted average limited partner units outstanding – basic	'		'		'		'
Total (in shares)	17,340,000		17,340,000		17,340,000		17,340,000
Weighted average limited partner units outstanding – diluted	'		'		'		'
Total (in shares)	17,340,000		17,340,000		17,340,000		17,340,000
Net income per limited partner unit – basic	'		'		'		'
Basic (in dollars per share)	$0.86		$0.57		$2.31		$1.79
Net income per limited partner unit – diluted	'		'		'		'
Diluted (in dollars per share)	$0.86		$0.57		$2.31		$1.79
Phantom Units	'		'		'		'
Net Income per Limited Partner Unit	'		'		'		'
Total (in shares)	11,654		'		11,323		'
Weighted average limited partner units outstanding – basic	'		'		'		'
Total (in shares)	11,654		'		11,323		'
Performance awards and phantom units	'		'		'		'
Net Income per Limited Partner Unit	'		'		'		'
Potentially dilutive securities included in the calculation of diluted net income per limited partner unit (in shares)	128,588		112,281		125,124		113,297
[1]	Financial statements for the nine months ended September 30, 2014 and the three months ended September 30, 2013 have been retrospectively recast to reflect the inclusion of the Jupiter natural gas gathering system (Jupiter). Financial statements for the nine months ended September 30, 2013 have been retrospectively recast to reflect the inclusion of Jupiter and Sunrise Pipeline, LLC (Sunrise). See Note B.
[2]	Financial statements for the nine months ended September 30, 2014 have been retrospectively recast to reflect the inclusion of Jupiter. Financial statements for the nine months ended September 30, 2013 have been retrospectively recast to reflect the inclusion of Jupiter and Sunrise. See Note B.

Subsidiary_Guarantors_Details

Subsidiary Guarantors (Details) (USD $)	9 Months Ended
	Sep. 30, 2014
Subsidiary Guarantors	'
Ownership interest held (as a percent)	100.00%
Restricted net assets	$0
EQT Midstream Finance Corporation	'
Subsidiary Guarantors	'
Ownership interest held (as a percent)	100.00%
Senior Notes | 4.00% Senior Notes Maturing 2024	'
Subsidiary Guarantors	'
Interest rate	4.00%

Subsequent_Events_Details

Subsequent Events (Details) (USD $)	3 Months Ended				9 Months Ended				0 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013		Oct. 21, 2014
									Subsequent Events
Subsequent Events	'		'		'		'		'
Cash distribution to the company's common and subordinated unitholders declared (in dollars per share)	$0.55	[1],[2]	$0.43	[1],[2]	$1.56	[1],[2]	$1.20	[1],[2]	$0.55
Partners’ capital:	'		'		'		'		'
Cash distribution declared to the general partner	'		'		'		'		$0.80
General partner's ownership interest	2.00%		2.00%		2.00%		2.00%		2.00%
Incentive distribution rights	'		'		'		'		$3.40
[1]	Represents the cash distributions declared related to the period presented. See Note K.
[2]	Financial statements for the nine months ended September 30, 2014 and the three months ended September 30, 2013 have been retrospectively recast to reflect the inclusion of the Jupiter natural gas gathering system (Jupiter). Financial statements for the nine months ended September 30, 2013 have been retrospectively recast to reflect the inclusion of Jupiter and Sunrise Pipeline, LLC (Sunrise). See Note B.