CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Millions	Jun. 30, 2026	Dec. 31, 2025
Assets
Cash and cash equivalents	$ 5.0	$ 1.9
Accounts receivable from contracts with customers:
Accounts receivable-trade	8.4	6.7
Accounts receivable-affiliate	$ 142.9	$ 143.5
Accounts Receivable, after Allowance for Credit Loss, Current, Related Party, Name [Extensible Enumeration]	us-gaap:RelatedPartyMember	us-gaap:RelatedPartyMember
Other current assets	$ 0.9	$ 6.9
Total current assets	157.2	159.0
Equity investments	83.2	81.5
Property, plant and equipment, at cost	5,415.8	5,374.6
Accumulated depreciation	(2,117.1)	(2,004.8)
Property, plant and equipment, net	3,298.7	3,369.8
Deferred tax asset	713.5	773.9
Other noncurrent assets	4.0	4.1
Total assets	4,256.6	4,388.3
Liabilities
Accounts payable—trade	31.7	24.9
Accounts payable-affiliate	$ 29.2	$ 26.9
Accounts Payable, Current, Related Party, Name [Extensible Enumeration]	us-gaap:RelatedPartyMember	us-gaap:RelatedPartyMember
Accrued liabilities	$ 97.5	$ 89.4
Current maturities of long-term debt	37.5	32.5
Other current liabilities	8.1	14.1
Total current liabilities	204.0	187.8
Long-term debt	3,642.5	3,739.5
Deferred tax liability	0.5	0.5
Other noncurrent liabilities	21.6	22.6
Total liabilities	3,868.6	3,950.4
Partners' capital
Total Class A and Class B partners' capital	514.6	568.3
Noncontrolling interest	(126.6)	(130.4)
Total partners' capital	388.0	437.9
Total liabilities and partners' capital	4,256.6	4,388.3
Class A Shares
Partners' capital
Common unitholders	$ 514.6	$ 568.3

Accounts Receivable Trade Current

No definition available.

Name:	hesm_AccountsReceivableTradeCurrent
Namespace Prefix:	hesm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).