| Cover Page - USD ($) | 12 Months Ended | ||
| Dec. 31, 2020 | Feb. 26, 2021 | Jun. 30, 2020 | |
| Cover [Abstract] | |||
| Entity Registrant Name | Summit Midstream Partners, LP | ||
| Entity Central Index Key | 0001549922 | ||
| Document Type | 10-K/A | ||
| Document Period End Date | Dec. 31, 2020 | ||
| Amendment Flag | true | ||
| Amendment Description | This Amendment No. 1 on Form 10-K/A (this “Amendment No. 1”) amends the Annual Report on Form 10-K of Summit Midstream Partners, LP (the “Partnership”) for the year ended December 31, 2020, as filed with the Securities and Exchange Commission (the “SEC”) on March 4, 2021 (the “Original Form 10-K”). This Amendment No. 1 is being filed for the sole purpose of filing the correct version of Exhibit 4.1, Description of Common Units. The Partnership inadvertently filed an incorrect version of Exhibit 4.1 with the Original Form 10-K. This Amendment No. 1 consists solely of the preceding cover page, this explanatory note, the information required by Item 15 of Form 10-K, a signature page and new certifications by our principal executive officer and principal financial officer as required by Item 15 of Part IV. In accordance with Rule 12b-15 promulgated under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), Item 15 of the Original Form 10-K has been amended and restated in its entirety. No other items or sub-items of the Original Form 10-K are being amended or restated by this Amendment No. 1. Except as otherwise expressly noted herein, this Amendment No. 1 does not amend, update or change any other items or disclosures contained in the Original Form 10-K, and accordingly, this Amendment No. 1 does not reflect or purport to reflect any information or events occurring after the filing date of the Original Form 10-K or modify or update those disclosures affected by subsequent events. Accordingly, this Amendment No. 1 should be read in conjunction with the Original Form 10-K and the Partnership’s other filings with the SEC. | ||
| Current Fiscal Year End Date | --12-31 | ||
| Entity Filer Category | Non-accelerated Filer | ||
| Entity Small Business | true | ||
| Entity Emerging Growth Company | false | ||
| Entity Shell Company | false | ||
| Entity Public Float | $ 45,998,000 | ||
| Document Fiscal Year Focus | 2020 | ||
| Document Fiscal Period Focus | FY | ||
| Trading Symbol | SMLP | ||
| Entity Well-known Seasoned Issuer | No | ||
| Entity Voluntary Filers | No | ||
| Entity Current Reporting Status | Yes | ||
| Entity Common Stock, Shares Outstanding | 6,110,092 | ||
| Entity Interactive Data Current | Yes | ||
| Title of 12(b) Security | Common Units | ||
| Security Exchange Name | NYSE | ||
| Entity File Number | 001-35666 | ||
| Entity Incorporation, State or Country Code | DE | ||
| Entity Tax Identification Number | 45-5200503 | ||
| Entity Address, Address Line One | 910 Louisiana Street | ||
| Entity Address, Address Line Two | Suite 4200 | ||
| Entity Address, City or Town | Houston | ||
| Entity Address, State or Province | TX | ||
| Entity Address, Postal Zip Code | 77002 | ||
| City Area Code | 832 | ||
| Local Phone Number | 413-4770 | ||
| Document Annual Report | true | ||
| Document Transition Report | false | ||
| ICFR Auditor Attestation Flag | true |
