Segments - Total Assets for Reportable Segments (Detail) - USD ($) $ in Millions		Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Total assets		$ 3,277.7	$ 2,991.2	[1]
Interest and Other
Segment Reporting Information [Line Items]
Total assets		67.0	118.4
Gathering Opco | Operating Segments
Segment Reporting Information [Line Items]
Total assets		1,844.9	1,544.0
Processing and Storage | Operating Segments
Segment Reporting Information [Line Items]
Total assets	[2]	1,055.1	1,008.6
Terminaling and Export | Operating Segments
Segment Reporting Information [Line Items]
Total assets		$ 310.7	$ 320.2

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

[2] Includes $107.8 million of investment in equity investees.