Related Party Transactions - Summary of Revenues From Contracts With Customers on Disaggregated Basis (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer including assessed tax	$ 334.2	$ 303.9	$ 959.3	$ 887.5
Other income	0.6		1.3
Total revenues	334.8	303.9	960.6	887.5
Oil and Gas Gathering Services
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer including assessed tax	160.5	135.3	454.2	397.4
Processing and Storage Services
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer including assessed tax	121.7	111.1	352.0	319.9
Terminaling and Export Services
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer including assessed tax	30.5	35.5	95.5	103.0
Water Gathering and Disposal Services
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer including assessed tax	$ 21.5	$ 22.0	$ 57.6	$ 67.2