Related Party Transactions - Summary of Revenues From Contracts With Customers on Disaggregated Basis (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer including assessed tax	$ 321.9	$ 313.0	$ 625.3	$ 625.1
Other income	2.1	0.4	3.7	0.7
Total revenues	324.0	313.4	629.0	625.8
Oil and Gas Gathering Services
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer including assessed tax	152.7	148.4	297.3	293.7
Processing and Storage Services
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer including assessed tax	121.6	116.5	235.4	230.3
Terminaling and Export Services
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer including assessed tax	26.2	30.3	51.4	65.0
Water Gathering and Disposal Services
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer including assessed tax	$ 21.4	$ 17.8	$ 41.2	$ 36.1