Earnings per Share/Limited Partner Unit - Summary of Reconciliation of Numerator and Denominator of Diluted Earnings (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Numerator
Net income attributable to Hess Midstream LP		$ 46.4	$ 24.0	$ 70.1
Effect of Exchange of Units of Partnership and Equal Number Shares of Common Stocks		571.4
Effect of income tax expense on additional income attributable to Hess Midstream LP	[1]	(139.4)
Diluted net income attributable to Hess Midstream LP		$ 478.4
Class A Shares
Denominator
Basic weighted average shares outstanding		25.6	18.0	18.0
Effect of dilutive securities
Diluted weighted average shares outstanding		25.7	18.1	18.0
Diluted net income attributable to Hess Midstream LP per Class A Share		$ 1.76
Class B Units/Shares
Denominator
Basic weighted average shares outstanding		246.7
Effect of dilutive securities
Diluted weighted average shares outstanding		272.4
Restricted equity-based awards		0.1

[1] (1) Income tax effect is calculated assuming 24.39% blended U.S. federal and state income tax rate.