Significant Accounting Policies - Components of Property and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Property and equipment	$ 11,330.5	$ 10,720.3
Accumulated depreciation	(4,774.5)	(4,332.0)
Property and equipment, net of accumulated depreciation	6,556.0	6,388.3
Transmission assets
Property, Plant and Equipment [Line Items]
Property and equipment	$ 1,452.0	1,442.2
Transmission assets | Minimum
Property, Plant and Equipment [Line Items]
Useful life	20 years
Transmission assets | Maximum
Property, Plant and Equipment [Line Items]
Useful life	25 years
Gathering systems
Property, Plant and Equipment [Line Items]
Property and equipment	$ 5,370.0	4,903.8
Gathering systems | Minimum
Property, Plant and Equipment [Line Items]
Useful life	20 years
Gathering systems | Maximum
Property, Plant and Equipment [Line Items]
Useful life	25 years
Gas processing plants and fractionation facilities
Property, Plant and Equipment [Line Items]
Property and equipment	$ 4,237.8	4,119.1
Gas processing plants and fractionation facilities | Minimum
Property, Plant and Equipment [Line Items]
Useful life	20 years
Gas processing plants and fractionation facilities | Maximum
Property, Plant and Equipment [Line Items]
Useful life	25 years
Other property and equipment
Property, Plant and Equipment [Line Items]
Property and equipment	$ 165.0	161.0
Other property and equipment | Minimum
Property, Plant and Equipment [Line Items]
Useful life	3 years
Other property and equipment | Maximum
Property, Plant and Equipment [Line Items]
Useful life	25 years
Construction in process
Property, Plant and Equipment [Line Items]
Property and equipment	$ 105.7	$ 94.2