Segments - Financial Data for Each Reportable Segment (Detail) - USD ($) $ in Millions		3 Months Ended				6 Months Ended
		Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021
Segment Reporting Information [Line Items]
Revenues and other income		$ 313.4		$ 294.8		$ 625.8	$ 583.6
Net income (loss)		151.8	$ 159.6	162.0	$ 159.6	311.4	321.6
Net income (loss) attributable to Hess Midstream LP		22.0		11.0		38.9	19.6
Depreciation expense		45.0		40.4		89.4	80.6
Proportional share of equity affiliates' depreciation		1.3		1.3		2.6	2.6
Income from equity investments		1.0		2.9		1.4	5.6
Interest expense, net		37.4		22.9		68.7	46.0
Income tax expense (benefit)		7.1		3.6		12.1	6.1
Adjusted EBITDA		242.6		230.2		484.2	456.9
Capital expenditures	[1]	71.7		46.4		108.8	69.5
Interest and Other
Segment Reporting Information [Line Items]
Net income (loss)		(46.0)		(28.1)		(84.6)	(55.8)
Net income (loss) attributable to Hess Midstream LP		(14.4)		(5.8)		(23.8)	(10.0)
Interest expense, net		37.4		22.9		68.7	46.0
Income tax expense (benefit)		7.1		3.6		12.1	6.1
Adjusted EBITDA		(1.5)		(1.6)		(3.8)	(3.7)
Gathering Opco | Operating Segments
Segment Reporting Information [Line Items]
Revenues and other income		166.2		154.6		329.8	307.3
Net income (loss)		95.2		92.4		193.4	184.8
Net income (loss) attributable to Hess Midstream LP		17.6		8.1		30.6	14.5
Depreciation expense		26.6		25.2		52.5	50.1
Adjusted EBITDA		(121.8)		117.6		245.9	234.9
Capital expenditures	[1]	67.7		38.2		103.4	57.6
Processing and Storage | Operating Segments
Segment Reporting Information [Line Items]
Revenues and other income		116.5		105.3		230.3	208.8
Net income (loss)		81.3		71.6		159.4	142.5
Net income (loss) attributable to Hess Midstream LP		15.0		6.3		25.4	11.1
Depreciation expense		14.4		11.2		28.8	22.4
Proportional share of equity affiliates' depreciation		1.3		1.3		2.6	2.6
Income from equity investments		1.0		2.9		1.4	5.6
Adjusted EBITDA		97.0		84.1		190.8	167.5
Capital expenditures	[1]	1.3		8.1		2.2	11.8
Terminaling and Export | Operating Segments
Segment Reporting Information [Line Items]
Revenues and other income		30.7		34.9		65.7	67.5
Net income (loss)		21.3		26.1		43.2	50.1
Net income (loss) attributable to Hess Midstream LP		3.8		2.4		6.7	4.0
Depreciation expense		4.0		4.0		8.1	8.1
Adjusted EBITDA		25.3		30.1		51.3	58.2
Capital expenditures	[1]	$ 2.7		$ 0.1		$ 3.2	$ 0.1

[1] Includes acquisition, expansion and maintenance capital expenditures, as applicable.