Related Party Transactions - Summary of Revenues From Contracts With Customers on Disaggregated Basis (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer including assessed tax	$ 312.1	$ 288.8
Other income	0.3
Total revenues	312.4	288.8
Oil and Gas Gathering Services
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer including assessed tax	145.3	128.7
Processing and Storage Services
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer including assessed tax	113.8	103.5
Terminaling and Export Services
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer including assessed tax	34.7	32.6
Water Gathering and Disposal Services
Disaggregation Of Revenue [Line Items]
Revenue from contract with customer including assessed tax	$ 18.3	$ 24.0