Debt and Interest Expense - Additional Information (Detail)	3 Months Ended
Mar. 31, 2020 USD ($)
Debt Instrument [Line Items]
Debt covenant, leverage ratio	550.00%
Ratio of debt to EBITDA	500.00%
Secured leverage ratio - Maximum	400.00%
Debt instrument covenant, description	The Credit Facilities contain representations and warranties, affirmative and negative covenants and events of default that the Partnership considers to be customary for an agreement of this type, including a covenant that requires the Partnership to maintain a ratio of total debt to EBITDA (as defined in the Credit Facilities) for the prior four fiscal quarters of not greater than 5.00 to 1.00 as of the last day of each fiscal quarter (5.50 to 1.00 during the specified period following certain acquisitions) and, prior to the Partnership obtaining an investment grade credit rating, a ratio of secured debt to EBITDA for the prior four fiscal quarters of not greater than 4.00 to 1.00 as of the last day of each fiscal quarter.
Carrying Value
Debt Instrument [Line Items]
Total debt	$ 1,814,600,000
Level 2
Debt Instrument [Line Items]
Total debt fair value	$ 1,448,700,000
Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility - Term	5 years
Maximum borrowing capacity	$ 1,000,000,000.0
Borrowings	$ 92,000,000.0
Revolving Credit Facility \| Minimum
Debt Instrument [Line Items]
Interest rate applicable margin	1.275%
Revolving Credit Facility \| Maximum
Debt Instrument [Line Items]
Interest rate applicable margin	2.00%
Term Loan A Facility
Debt Instrument [Line Items]
Credit facility - Term	5 years
Maximum borrowing capacity	$ 400,000,000.0
Borrowings	$ 400,000,000.0
Syndicated Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility - Term	5 years
Syndicated Revolving Credit Facility \| Minimum
Debt Instrument [Line Items]
Interest rate applicable margin	1.275%
Syndicated Revolving Credit Facility \| Maximum
Debt Instrument [Line Items]
Interest rate applicable margin	2.00%
Fixed-Rate Senior Notes
Debt Instrument [Line Items]
Debt covenant, leverage ratio	425.00%
5.625% Fixed Rate Senior Notes due 2026 \| Hess Midstream Operations LP
Debt Instrument [Line Items]
Fixed-rate senior notes	$ 800,000,000.0
5.625% Fixed Rate Senior Notes due 2026 \| Fixed-Rate Senior Notes
Debt Instrument [Line Items]
Debt instrument due year	2026
5.625% Fixed Rate Senior Notes due 2026 \| Fixed-Rate Senior Notes \| Hess Midstream Operations LP
Debt Instrument [Line Items]
Debt instrument interest rate	5.625%
Debt instrument due year	2026
Frequency of periodic interest payment	semi‑annually
Interest payment terms	Interest is payable semi‑annually on February 15 and August 15.
5.125% Fixed Rate Senior Notes due 2028
Debt Instrument [Line Items]
Fixed-rate senior notes	$ 550,000,000.0
5.125% Fixed Rate Senior Notes due 2028 \| Fixed-Rate Senior Notes
Debt Instrument [Line Items]
Debt instrument interest rate	5.125%
Debt instrument due year	2028
Frequency of periodic interest payment	semi‑annually
Interest payment terms	Interest is payable semi‑annually on June 15 and December 15.

Debt instrument maturity year.

No definition available.

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Balance Type:	na
Period Type:	duration

- Definition

Leverage ratio.

+ References

No definition available.

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Ratio of debt to EBITDA.

+ References

No definition available.

+ Details

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Namespace Prefix:	hesm_
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Balance Type:	na
Period Type:	duration

- Definition

Secured leverage ratio.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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- Definition

Description of minimum financial levels (for example, tangible net worth and working capital) and achievement of certain financial ratios (for example, working capital ratio and debt service coverage ratio), and adherence to certain clauses which generally require or restrict certain actions (for example, entering into a debt arrangement with equal or greater seniority, and selling or discontinuing a certain business segment or material subsidiary) to be in compliance with the covenant clauses of the debt agreement. May also include a discussion of the adverse consequences that would result if the entity violates or fails to satisfy the covenants.

+ References

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- Definition

Description of the frequency of periodic payments (monthly, quarterly, annual).

+ References

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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

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Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Description of the payment terms of the debt instrument (for example, whether periodic payments include principal and frequency of payments) and discussion about any contingencies associated with the payment.

+ References

+ Details

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

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+ Details

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Period Type:	instant

- Definition

Period remaining on line of credit facility before it terminates, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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Balance Type:	na
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- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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Namespace Prefix:	us-gaap_
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Balance Type:	credit
Period Type:	instant

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (b)(3)
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+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders.

+ References

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Period Type:	instant

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