Property, Plant and Equipment - Components of Property, Plant and Equipment (Detail) - USD ($) $ in Millions	Jun. 30, 2024	Dec. 31, 2023
Property Plant And Equipment [Line Items]
Total property, plant and equipment, at cost	$ 4,926.7	$ 4,818.7
Accumulated depreciation	(1,689.4)	(1,589.5)
Property, plant and equipment, net	3,237.3	3,229.2
Logistics Facilities and Railcars
Property Plant And Equipment [Line Items]
Total property, plant and equipment, at cost	$ 409.2	409.2
Logistics Facilities and Railcars | Minimum
Property Plant And Equipment [Line Items]
Property, plant and equipment, Estimated useful life	20 years
Logistics Facilities and Railcars | Maximum
Property Plant And Equipment [Line Items]
Property, plant and equipment, Estimated useful life	25 years
Storage Facilities
Property Plant And Equipment [Line Items]
Total property, plant and equipment, at cost	$ 19.9	19.9
Storage Facilities | Minimum
Property Plant And Equipment [Line Items]
Property, plant and equipment, Estimated useful life	20 years
Storage Facilities | Maximum
Property Plant And Equipment [Line Items]
Property, plant and equipment, Estimated useful life	25 years
Other
Property Plant And Equipment [Line Items]
Total property, plant and equipment, at cost	$ 28.2	28.0
Other | Minimum
Property Plant And Equipment [Line Items]
Property, plant and equipment, Estimated useful life	20 years
Other | Maximum
Property Plant And Equipment [Line Items]
Property, plant and equipment, Estimated useful life	25 years
Construction-In-Progress
Property Plant And Equipment [Line Items]
Total property, plant and equipment, at cost	$ 134.6	136.3
Gathering Assets | Pipelines
Property Plant And Equipment [Line Items]
Property, plant and equipment, Estimated useful life	22 years
Total property, plant and equipment, at cost	$ 1,740.8	1,703.7
Gathering Assets | Compressors, Pumping Stations and Terminals
Property Plant And Equipment [Line Items]
Total property, plant and equipment, at cost	$ 1,091.1	1,026.4
Gathering Assets | Compressors, Pumping Stations and Terminals | Minimum
Property Plant And Equipment [Line Items]
Property, plant and equipment, Estimated useful life	22 years
Gathering Assets | Compressors, Pumping Stations and Terminals | Maximum
Property Plant And Equipment [Line Items]
Property, plant and equipment, Estimated useful life	25 years
Gas Plant Assets | Pipelines, Pipes and Valves
Property Plant And Equipment [Line Items]
Total property, plant and equipment, at cost	$ 460.0	460.0
Gas Plant Assets | Pipelines, Pipes and Valves | Minimum
Property Plant And Equipment [Line Items]
Property, plant and equipment, Estimated useful life	22 years
Gas Plant Assets | Pipelines, Pipes and Valves | Maximum
Property Plant And Equipment [Line Items]
Property, plant and equipment, Estimated useful life	25 years
Gas Plant Assets | Equipment
Property Plant And Equipment [Line Items]
Total property, plant and equipment, at cost	$ 428.2	428.2
Gas Plant Assets | Equipment | Minimum
Property Plant And Equipment [Line Items]
Property, plant and equipment, Estimated useful life	12 years
Gas Plant Assets | Equipment | Maximum
Property Plant And Equipment [Line Items]
Property, plant and equipment, Estimated useful life	30 years
Gas Plant Assets | Processing and Fractionation Facilities
Property Plant And Equipment [Line Items]
Property, plant and equipment, Estimated useful life	25 years
Total property, plant and equipment, at cost	$ 432.4	424.7
Gas Plant Assets | Buildings
Property Plant And Equipment [Line Items]
Property, plant and equipment, Estimated useful life	35 years
Total property, plant and equipment, at cost	$ 182.3	$ 182.3