Segments - Financial Data for Each Reportable Segment (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Revenues and other income		$ 1,203.8	$ 1,091.9	$ 848.3
Net income (loss)		617.8	484.9	317.7
Net income (loss) attributable to Hess Midstream LP		46.4	24.0	70.1
Depreciation expense		165.6	156.9	142.5
Proportional share of equity affiliates' depreciation		5.1	5.1	2.0
Income from equity investments		10.6	10.3	3.4
Interest expense, net		105.4	94.7	62.4
Income tax expense (benefit)		14.6	7.3	(0.1)
Transaction costs				26.2
Gain on sale of property, plant and equipment			0.1
Adjusted EBITDA		908.5	748.8	550.7
Capital expenditures	[1]	183.0	253.0	416.3
Interest and Other
Segment Reporting Information [Line Items]
Net income (loss)		(127.3)	(108.0)	(99.2)
Net income (loss) attributable to Hess Midstream LP		(25.5)	(13.6)	(9.6)
Interest expense, net		105.4	94.7	62.4
Income tax expense (benefit)		14.6	7.3	(0.1)
Transaction costs				26.2
Adjusted EBITDA		(7.3)	(6.0)	(10.7)
Gathering Opco | Operating Segments
Segment Reporting Information [Line Items]
Revenues and other income		630.6	561.9	422.9
Net income (loss)		377.6	300.7	186.0
Net income (loss) attributable to Hess Midstream LP		36.3	19.2	34.6
Depreciation expense		101.0	96.0	81.6
Gain on sale of property, plant and equipment			0.1
Adjusted EBITDA		478.6	396.6	267.6
Capital expenditures	[1]	154.0	96.2	373.6
Processing and Storage | Operating Segments
Segment Reporting Information [Line Items]
Revenues and other income		435.7	370.6	295.3
Net income (loss)		263.8	218.7	176.1
Net income (loss) attributable to Hess Midstream LP		25.5	13.7	34.6
Depreciation expense		48.4	44.8	44.7
Proportional share of equity affiliates' depreciation		5.1	5.1	2.0
Income from equity investments		10.6	10.3	3.4
Adjusted EBITDA		317.3	268.6	222.8
Capital expenditures	[1]	28.8	156.2	42.5
Terminaling and Export | Operating Segments
Segment Reporting Information [Line Items]
Revenues and other income		137.5	159.4	130.1
Net income (loss)		103.7	73.5	54.8
Net income (loss) attributable to Hess Midstream LP		10.1	4.7	10.5
Depreciation expense		16.2	16.1	16.2
Adjusted EBITDA		119.9	89.6	71.0
Capital expenditures	[1]	$ 0.2	$ 0.6	$ 0.2

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