Segments - Total Assets for Reportable Segments (Parenthetical) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	[1]
Segment Reporting Information [Line Items]
Cash contributed to acquire equity method investments	$ 33.0	$ 67.3
Processing and Storage
Segment Reporting Information [Line Items]
Cash contributed to acquire equity method investments	$ 107.8

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