Segments - Total Assets for Reportable Segments (Detail) - USD ($) $ in Millions		Mar. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Total assets		$ 3,578.5	$ 3,588.2
Interest and Other
Segment Reporting Information [Line Items]
Total assets		188.8	191.2
Gathering Opco | Operating Segments
Segment Reporting Information [Line Items]
Total assets		2,036.1	2,022.0
Processing and Storage | Operating Segments
Segment Reporting Information [Line Items]
Total assets	[1]	1,079.7	1,099.2
Terminaling and Export | Operating Segments
Segment Reporting Information [Line Items]
Total assets		$ 273.9	$ 275.8

[1] Includes investment in equity investees of $92.9 million as of March 31, 2023 and $93.9 million as of December 31, 2022.