CONDENSED CONSOLIDATING FINANCIAL INFORMATION - Condensed Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues:
Total revenues	$ 128,183	$ 101,792	$ 245,503	$ 237,597
Costs and expenses:
Cost of natural gas and NGLs	$ 24,384	$ 9,099	$ 44,670	$ 18,151
Type of Cost, Good or Service [Extensible List]	us-gaap:OilAndGasPurchasedMember	us-gaap:OilAndGasPurchasedMember	us-gaap:OilAndGasPurchasedMember	us-gaap:OilAndGasPurchasedMember
Operation and maintenance	$ 24,466	$ 24,016	$ 49,070	$ 47,708
General and administrative	13,484	12,949	27,926	27,081
Depreciation and amortization	26,784	28,688	53,461	57,257
Transaction costs	0	119	0	119
Loss (gain) on asset sales, net	62	67	(12)	70
Long-lived asset impairment	587	3	587	287
Total costs and expenses	89,767	74,941	175,702	150,673
Other income	27	64	20	135
Interest expense	(14,837)	(17,553)	(29,959)	(34,269)
Early extinguishment of debt	0	0	0	(22,020)
Deferred Purchase Price Obligation	(69,305)	5,058	(90,963)	(15,825)
(Loss) income before income taxes and loss from equity method investees	(45,699)	14,420	(51,101)	14,945
Income tax (expense) benefit	(294)	211	(123)	(241)
Loss from equity method investees	(3,920)	(3,385)	(2,534)	(4,041)
Equity in earnings of consolidated subsidiaries	0	0	0	0
Net (loss) income	(49,913)	11,246	(53,758)	10,663
Consolidating adjustments
Revenues:
Total revenues	0	0	0	0
Costs and expenses:
Cost of natural gas and NGLs	$ 0	$ 0	$ 0	$ 0
Type of Cost, Good or Service [Extensible List]	us-gaap:OilAndGasPurchasedMember	us-gaap:OilAndGasPurchasedMember	us-gaap:OilAndGasPurchasedMember	us-gaap:OilAndGasPurchasedMember
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
Loss (gain) 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
(Loss) income before income taxes and loss from equity method investees	0	0	0	0
Income tax (expense) benefit	0	0	0	0
Loss from equity method investees	0	0	0	0
Equity in earnings of consolidated subsidiaries	(55,043)	(29,925)	(106,327)	(110,331)
Net (loss) income	(55,043)	(29,925)	(106,327)	(110,331)
Gathering Services and Related Fees
Revenues:
Total revenues	89,585	84,801	173,946	202,814
Gathering Services and Related Fees | Consolidating adjustments
Revenues:
Total revenues	0	0	0	0
Natural Gas, NGLs and Condensate Sales
Revenues:
Total revenues	31,891	10,595	58,008	21,715
Natural Gas, NGLs and Condensate Sales | Consolidating adjustments
Revenues:
Total revenues	0	0	0	0
Other Revenues
Revenues:
Total revenues	6,707	6,396	13,549	13,068
Other Revenues | Consolidating adjustments
Revenues:
Total revenues	0	0	0	0
Summit Midstream Partners, LP | Reportable Legal Entities
Revenues:
Total revenues	0	0	0	0
Costs and expenses:
Cost of natural gas and NGLs	$ 0	$ 0	$ 0	$ 0
Type of Cost, Good or Service [Extensible List]	us-gaap:OilAndGasPurchasedMember	us-gaap:OilAndGasPurchasedMember	us-gaap:OilAndGasPurchasedMember	us-gaap:OilAndGasPurchasedMember
Operation and maintenance	$ 0	$ 0	$ 0	$ 0
General and administrative	0	0	0	0
Depreciation and amortization	444	154	876	308
Transaction costs		119		119
Loss (gain) on asset sales, net	0	0	0	0
Long-lived asset impairment	0	0	0	0
Total costs and expenses	444	273	876	427
Other income	27	64	20	135
Interest expense	0	0	0	0
Early extinguishment of debt				0
Deferred Purchase Price Obligation	(69,305)	5,058	(90,963)	(15,825)
(Loss) income before income taxes and loss from equity method investees	(69,722)	4,849	(91,819)	(16,117)
Income tax (expense) benefit	(294)	211	(123)	(241)
Loss from equity method investees	0	0	0	0
Equity in earnings of consolidated subsidiaries	20,103	6,186	38,184	27,021
Net (loss) income	(49,913)	11,246	(53,758)	10,663
Summit Midstream Partners, LP | Gathering Services and Related Fees | Reportable Legal Entities
Revenues:
Total revenues	0	0	0	0
Summit Midstream Partners, LP | Natural Gas, NGLs and Condensate Sales | Reportable Legal Entities
Revenues:
Total revenues	0	0	0	0
Summit Midstream Partners, LP | Other Revenues | Reportable Legal Entities
Revenues:
Total revenues	0	0	0	0
Co-Issuers | Reportable Legal Entities
Revenues:
Total revenues	0	0	0	0
Costs and expenses:
Cost of natural gas and NGLs	$ 0	$ 0	$ 0	$ 0
Type of Cost, Good or Service [Extensible List]	us-gaap:OilAndGasPurchasedMember	us-gaap:OilAndGasPurchasedMember	us-gaap:OilAndGasPurchasedMember	us-gaap:OilAndGasPurchasedMember
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
Loss (gain) 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	(14,837)	(17,553)	(29,959)	(34,269)
Early extinguishment of debt				(22,020)
Deferred Purchase Price Obligation	0	0	0	0
(Loss) income before income taxes and loss from equity method investees	(14,837)	(17,553)	(29,959)	(56,289)
Income tax (expense) benefit	0	0	0	0
Loss from equity method investees	0	0	0	0
Equity in earnings of consolidated subsidiaries	34,940	23,739	68,143	83,310
Net (loss) income	20,103	6,186	38,184	27,021
Co-Issuers | Gathering Services and Related Fees | Reportable Legal Entities
Revenues:
Total revenues	0	0	0	0
Co-Issuers | Natural Gas, NGLs and Condensate Sales | Reportable Legal Entities
Revenues:
Total revenues	0	0	0	0
Co-Issuers | Other Revenues | Reportable Legal Entities
Revenues:
Total revenues	0	0	0	0
Guarantor Subsidiaries | Reportable Legal Entities
Revenues:
Total revenues	112,291	84,606	214,601	204,839
Costs and expenses:
Cost of natural gas and NGLs	$ 24,384	$ 9,099	$ 44,670	$ 18,151
Type of Cost, Good or Service [Extensible List]	us-gaap:OilAndGasPurchasedMember	us-gaap:OilAndGasPurchasedMember	us-gaap:OilAndGasPurchasedMember	us-gaap:OilAndGasPurchasedMember
Operation and maintenance	$ 22,221	$ 22,169	$ 44,374	$ 44,189
General and administrative	11,907	10,886	24,244	23,371
Depreciation and amortization	22,776	25,282	45,637	50,524
Transaction costs		0		0
Loss (gain) on asset sales, net	(1)	67	(75)	70
Long-lived asset impairment	587	2	587	2
Total costs and expenses	81,874	67,505	159,437	136,307
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
(Loss) income before income taxes and loss from equity method investees	30,417	17,101	55,164	68,532
Income tax (expense) 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 (loss) income	30,417	17,101	55,164	68,532
Guarantor Subsidiaries | Gathering Services and Related Fees | Reportable Legal Entities
Revenues:
Total revenues	73,891	67,679	143,357	170,192
Guarantor Subsidiaries | Natural Gas, NGLs and Condensate Sales | Reportable Legal Entities
Revenues:
Total revenues	31,891	10,595	58,008	21,715
Guarantor Subsidiaries | Other Revenues | Reportable Legal Entities
Revenues:
Total revenues	6,509	6,332	13,236	12,932
Non-Guarantor Subsidiaries | Reportable Legal Entities
Revenues:
Total revenues	15,892	17,186	30,902	32,758
Costs and expenses:
Cost of natural gas and NGLs	$ 0	$ 0	$ 0	$ 0
Type of Cost, Good or Service [Extensible List]	us-gaap:OilAndGasPurchasedMember	us-gaap:OilAndGasPurchasedMember	us-gaap:OilAndGasPurchasedMember	us-gaap:OilAndGasPurchasedMember
Operation and maintenance	$ 2,245	$ 1,847	$ 4,696	$ 3,519
General and administrative	1,577	2,063	3,682	3,710
Depreciation and amortization	3,564	3,252	6,948	6,425
Transaction costs		0		0
Loss (gain) on asset sales, net	63	0	63	0
Long-lived asset impairment	0	1	0	285
Total costs and expenses	7,449	7,163	15,389	13,939
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
(Loss) income before income taxes and loss from equity method investees	8,443	10,023	15,513	18,819
Income tax (expense) benefit	0	0	0	0
Loss from equity method investees	(3,920)	(3,385)	(2,534)	(4,041)
Equity in earnings of consolidated subsidiaries	0	0	0	0
Net (loss) income	4,523	6,638	12,979	14,778
Non-Guarantor Subsidiaries | Gathering Services and Related Fees | Reportable Legal Entities
Revenues:
Total revenues	15,694	17,122	30,589	32,622
Non-Guarantor Subsidiaries | Natural Gas, NGLs and Condensate Sales | Reportable Legal Entities
Revenues:
Total revenues	0	0	0	0
Non-Guarantor Subsidiaries | Other Revenues | Reportable Legal Entities
Revenues:
Total revenues	$ 198	$ 64	$ 313	$ 136