CONSOLIDATED STATEMENTS OF OPERATIONS (UNAUDITED) - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenues
Affiliate services	$ 288.8	$ 290.6
Type of Revenue [Extensible List]	hesm:AffiliateServicesMember	hesm:AffiliateServicesMember
Other income		$ 0.2
Total revenues	$ 288.8	290.8
Costs and expenses
Operating and maintenance expenses (exclusive of depreciation shown separately below)	59.8	91.9
Depreciation expense	40.2	38.5
General and administrative expenses	6.3	7.6
Total costs and expenses	106.3	138.0
Income from operations	182.5	152.8
Income from equity investments	2.7	2.7
Interest expense, net	23.1	24.8
Income before income tax expense	162.1	130.7
Income tax expense	2.5	1.7
Net income	159.6	129.0
Less: Net income attributable to noncontrolling interest	151.0	122.5
Net income attributable to Hess Midstream LP	8.6	6.5
Class A Shares
Costs and expenses
Net income	$ 8.6	$ 6.5
Net income attributable to Hess Midstream LP per Class A share:
Net income attributable to Hess Midstream LP per Class A share, Basic	$ 0.45	$ 0.37
Net income attributable to Hess Midstream LP per Class A share, Diluted	$ 0.43	$ 0.35
Weighted average Class A shares outstanding
Weighted average Class A shares outstanding subsequent to the restructuring, Basic	19.3	18.0
Weighted average Class A shares outstanding subsequent to the restructuring, Diluted	19.4	18.0