Segments - Total Assets for Reportable Segments (Detail) - USD ($) $ in Millions		Mar. 31, 2024	Dec. 31, 2023
Segment Reporting Information [Line Items]
Total assets		$ 3,862.8	$ 3,789.5
Interest and Other
Segment Reporting Information [Line Items]
Total assets		422.2	338.1
Gathering Opco | Operating Segments
Segment Reporting Information [Line Items]
Total assets		2,139.0	2,138.6
Processing and Storage | Operating Segments
Segment Reporting Information [Line Items]
Total assets	[1]	1,041.7	1,048.4
Terminaling and Export | Operating Segments
Segment Reporting Information [Line Items]
Total assets		$ 259.9	$ 264.4

[1] Includes investment in equity investees of $89.4 million as of March 31, 2024 and $90.2 million as of December 31, 2023.