CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Millions, $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018		Dec. 31, 2017
Revenues
Affiliate services		$ 847.6	$ 712.0	[1]	$ 579.5	[1]
Type of Revenue [Extensible List]		hesm:AffiliateServicesMember	hesm:AffiliateServicesMember	[1]	hesm:AffiliateServicesMember	[1]
Other income		$ 0.7	$ 0.7	[1]
Total revenues		848.3	712.7	[1]	$ 579.5	[1]
Costs and expenses
Operating and maintenance expenses (exclusive of depreciation shown separately below)		276.8	193.5	[1]	186.0	[1]
Depreciation expense		142.5	126.9	[1]	116.5	[1]
General and administrative expenses		52.4	14.1	[1]	13.9	[1]
Total costs and expenses		471.7	334.5	[1]	316.4	[1]
Income from operations		376.6	378.2	[1]	263.1	[1]
Income from equity investments		3.4
Interest expense, net		62.4	53.3	[1]	25.8	[1]
Gain on sale of property, plant and equipment	[1]		0.6		4.7
Income before income tax expense (benefit)		317.6	325.5	[1]	242.0	[1]
Income tax expense (benefit)		(0.1)
Net income		317.7	325.5	[1]	242.0	[1]
Less: Net income (loss) attributable to net parent investment		(55.0)	(46.8)	[1]	25.4	[1]
Less: Net income (loss) attributable to noncontrolling interest		302.6	301.5	[1]	175.4	[1]
Net income attributable to Hess Midstream LP		70.1	70.8	[1]	41.2	[1]
Less: General partner's interest in net income prior to the Restructuring		3.4	1.7	[1]	0.8	[1]
Limited partners' interest in net income		$ 66.7	$ 69.1	[1]	$ 40.4	[1]
Common Units
Net income attributable to Hess Midstream LP per limited partner unit (basic and diluted):
Net income attributable to Hess Midstream Partners per limited partner unit	[1]		$ 1.27		$ 0.75
Weighted average Class A shares outstanding subsequent to the Restructuring (basic and diluted):					26.9
Weighted average limited partner units outstanding prior to the Restructuring, Basic:
Units outstanding prior to the Restructuring, Basic		27.3	27.3	[1]	26.9	[1]
Weighted average limited partner units outstanding prior to the Restructuring, Diluted:
Units outstanding prior to the Restructuring, Diluted		27.5	27.4	[1]	26.9	[1]
Subordinated Units
Net income attributable to Hess Midstream LP per limited partner unit (basic and diluted):
Net income attributable to Hess Midstream Partners per limited partner unit	[1]		$ 1.27		$ 0.75
Weighted average Class A shares outstanding subsequent to the Restructuring (basic and diluted):					26.9
Weighted average limited partner units outstanding prior to the Restructuring, Basic:
Units outstanding prior to the Restructuring, Basic		27.3	27.3	[1]	26.9	[1]
Weighted average limited partner units outstanding prior to the Restructuring, Diluted:
Units outstanding prior to the Restructuring, Diluted		27.3	27.3	[1]	26.9	[1]
Common Class A
Net income attributable to Hess Midstream LP per Class A share/limited partner unit:
Net income attributable to Hess Midstream LP per Class A share/limited partner unit, Basic		$ 1.21
Net income attributable to Hess Midstream LP per Class A share/limited partner unit, Diluted		$ 1.20
Net income attributable to Hess Midstream LP per limited partner unit (basic and diluted):
Weighted average Class A shares outstanding subsequent to the Restructuring (basic and diluted):		18.0

[1] The financial information presented in this report has been retrospectively adjusted for the acquisition of Hess Infrastructure Partners LP.