Revenues (Disaggregation of Revenue) (Details) - 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]
Total revenues	$ 1,021.2	$ 1,448.0	$ 2,284.3	$ 3,031.8
Natural Gas Gathering
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	34.2	57.4	72.1	105.7
Crude Oil Gathering
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	17.4	16.0	33.5	31.8
Water Gathering
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	54.6	44.5	105.7	81.4
Natural Gas Processing
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	24.7	20.9	49.3	36.4
Natural Gas Compression
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues		3.1		6.6
Crude Oil Storage
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.5	0.8	1.0	1.2
NGL Storage
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	2.1	1.9	4.3	4.7
Crude Oil Pipeline
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	1.8	2.1	3.5	3.9
NGL Pipeline
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0	0.1	0.1	0.1
NGL Transportation
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	4.4	5.5	10.2	11.3
Crude Oil Rail Loading
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.2		0.4	0.4
Natural Gas Product Sales
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	61.8	183.6	154.7	294.4
Crude Oil Product Sales
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	439.4	526.5	797.6	1,017.4
NGL Product Sales
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	337.0	473.7	861.2	1,119.3
Water Product Sales
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.9	1.3	1.9	2.9
Other revenue
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.9	0.4	1.3	0.9
Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Total revenues	(93.6)	(151.6)	(226.8)	(279.0)
Intersegment Eliminations | Natural Gas Gathering
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0	0.0	0.0	0.0
Intersegment Eliminations | Crude Oil Gathering
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0	0.0	0.0	0.0
Intersegment Eliminations | Water Gathering
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0	0.0	0.0	0.0
Intersegment Eliminations | Natural Gas Processing
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0	0.0	0.0	0.0
Intersegment Eliminations | Natural Gas Compression
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues		0.0		0.0
Intersegment Eliminations | Crude Oil Storage
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	(0.1)	(0.1)	(0.2)	(0.2)
Intersegment Eliminations | NGL Storage
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0	0.0	0.0	0.0
Intersegment Eliminations | Crude Oil Pipeline
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0	(0.1)	0.0	(0.1)
Intersegment Eliminations | NGL Pipeline
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	(5.7)	0.0	(10.9)	0.0
Intersegment Eliminations | NGL Transportation
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0	0.0	0.0	0.0
Intersegment Eliminations | Crude Oil Rail Loading
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0		0.0	0.0
Intersegment Eliminations | Natural Gas Product Sales
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	(47.8)	(73.5)	(112.8)	(125.6)
Intersegment Eliminations | Crude Oil Product Sales
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	(12.7)	(12.9)	(42.7)	(24.1)
Intersegment Eliminations | NGL Product Sales
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	(27.1)	(65.0)	(60.0)	(129.0)
Intersegment Eliminations | Water Product Sales
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0	0.0	0.0	0.0
Intersegment Eliminations | Other revenue
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	(0.2)	0.0	(0.2)	0.0
Operating Segments | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total revenues	300.0	431.0	614.4	793.6
Operating Segments | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total revenues	151.9	35.3	317.0	66.0
Operating Segments | Storage and Logistics
Disaggregation of Revenue [Line Items]
Total revenues	662.9	1,133.3	1,579.7	2,451.2
Operating Segments | Natural Gas Gathering | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	29.7	32.9	63.3	58.8
Operating Segments | Natural Gas Gathering | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	4.5	24.5	8.8	46.9
Operating Segments | Natural Gas Gathering | Storage and Logistics
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0	0.0	0.0	0.0
Operating Segments | Crude Oil Gathering | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	15.2	14.1	29.4	28.9
Operating Segments | Crude Oil Gathering | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	2.2	1.9	4.1	2.9
Operating Segments | Crude Oil Gathering | Storage and Logistics
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0	0.0	0.0	0.0
Operating Segments | Water Gathering | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	46.4	41.2	88.9	75.9
Operating Segments | Water Gathering | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	8.2	3.3	16.8	5.5
Operating Segments | Water Gathering | Storage and Logistics
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0	0.0	0.0	0.0
Operating Segments | Natural Gas Processing | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	17.4	19.7	36.6	34.1
Operating Segments | Natural Gas Processing | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	7.3	1.2	12.7	2.3
Operating Segments | Natural Gas Processing | Storage and Logistics
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0	0.0	0.0	0.0
Operating Segments | Natural Gas Compression | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues		0.0		0.0
Operating Segments | Natural Gas Compression | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues		3.1		6.6
Operating Segments | Natural Gas Compression | Storage and Logistics
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues		0.0		0.0
Operating Segments | Crude Oil Storage | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.5	0.6	1.1	1.1
Operating Segments | Crude Oil Storage | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0	0.0	0.0	0.0
Operating Segments | Crude Oil Storage | Storage and Logistics
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.1	0.3	0.1	0.3
Operating Segments | NGL Storage | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0	0.0	0.0	0.0
Operating Segments | NGL Storage | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0	0.0	0.0	0.0
Operating Segments | NGL Storage | Storage and Logistics
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	2.1	1.9	4.3	4.7
Operating Segments | Crude Oil Pipeline | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	1.2	1.5	2.3	2.7
Operating Segments | Crude Oil Pipeline | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.1	0.3	0.3	0.4
Operating Segments | Crude Oil Pipeline | Storage and Logistics
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.5	0.4	0.9	0.9
Operating Segments | NGL Pipeline | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0	0.0	0.0	0.0
Operating Segments | NGL Pipeline | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	5.7	0.0	10.9	0.0
Operating Segments | NGL Pipeline | Storage and Logistics
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0	0.1	0.1	0.1
Operating Segments | NGL Transportation | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0	0.0	0.0	0.0
Operating Segments | NGL Transportation | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0	0.0	0.0	0.0
Operating Segments | NGL Transportation | Storage and Logistics
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	4.4	5.5	10.2	11.3
Operating Segments | Crude Oil Rail Loading | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0		0.0	0.0
Operating Segments | Crude Oil Rail Loading | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0		0.0	0.0
Operating Segments | Crude Oil Rail Loading | Storage and Logistics
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.2		0.4	0.4
Operating Segments | Natural Gas Product Sales | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	22.5	95.6	67.7	159.5
Operating Segments | Natural Gas Product Sales | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	32.1	0.6	66.1	0.9
Operating Segments | Natural Gas Product Sales | Storage and Logistics
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	55.0	160.9	133.7	259.6
Operating Segments | Crude Oil Product Sales | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	128.5	145.9	237.8	274.0
Operating Segments | Crude Oil Product Sales | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.2	0.0	0.3	0.0
Operating Segments | Crude Oil Product Sales | Storage and Logistics
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	323.4	393.5	602.2	767.5
Operating Segments | NGL Product Sales | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	36.8	77.5	83.7	154.4
Operating Segments | NGL Product Sales | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	92.2	0.0	198.1	0.0
Operating Segments | NGL Product Sales | Storage and Logistics
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	235.1	461.2	639.4	1,093.9
Operating Segments | Water Product Sales | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.9	1.3	1.9	2.9
Operating Segments | Water Product Sales | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0	0.0	0.0	0.0
Operating Segments | Water Product Sales | Storage and Logistics
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0	0.0	0.0	0.0
Operating Segments | Other revenue | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.3	0.4	0.6	0.6
Operating Segments | Other revenue | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.0	0.0	0.0	0.0
Operating Segments | Other revenue | Storage and Logistics
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.8	0.0	0.9	0.3
Revenue from Contract with Customer
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	979.9	1,337.8	2,096.8	2,718.4
Revenue from Contract with Customer | Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	(93.6)	(151.6)	(226.8)	(279.0)
Revenue from Contract with Customer | Operating Segments | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	299.4	430.7	613.3	792.9
Revenue from Contract with Customer | Operating Segments | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	152.5	34.9	318.1	65.5
Revenue from Contract with Customer | Operating Segments | Storage and Logistics
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	621.6	1,023.8	1,392.2	2,139.0
Product and Service, Other
Disaggregation of Revenue [Line Items]
Non-Topic 606 revenues	41.3	110.2	187.5	313.4
Product and Service, Other | Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Non-Topic 606 revenues	0.0	0.0	0.0	0.0
Product and Service, Other | Operating Segments | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Non-Topic 606 revenues	0.6	0.3	1.1	0.7
Product and Service, Other | Operating Segments | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Non-Topic 606 revenues	(0.6)	0.4	(1.1)	0.5
Product and Service, Other | Operating Segments | Storage and Logistics
Disaggregation of Revenue [Line Items]
Non-Topic 606 revenues	$ 41.3	$ 109.5	$ 187.5	$ 312.2