Revenues (Disaggregation of Revenue) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Total revenues	$ 1,139.4	$ 1,566.0	$ 3,423.7	$ 4,597.8
Natural Gas Gathering
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	37.0	43.5	109.1	149.2
Crude Oil Gathering
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	18.8	16.4	52.3	48.2
Water Gathering
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	59.4	49.3	165.1	130.7
Natural Gas Processing
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	26.9	25.5	76.2	61.9
Natural Gas Compression
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues		4.7		11.3
Crude Oil Storage
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.6	0.7	1.6	1.9
NGL Storage
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	2.1	2.2	6.4	6.9
Crude Oil Pipeline
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	2.1	2.2	5.6	6.1
NGL Pipeline
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.2	0.1	0.3	0.2
NGL Transportation
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	2.2	5.0	12.4	16.3
Crude Oil Rail Loading
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.2		0.6	0.4
Natural Gas Product Sales
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	83.0	296.8	237.7	591.2
Crude Oil Product Sales
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	477.4	473.9	1,275.0	1,491.3
NGL Product Sales
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	378.7	557.3	1,239.9	1,676.6
Water Product Sales
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	1.0	2.1	2.9	5.0
Other revenue
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.4	0.5	1.7	1.4
Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Total revenues	(123.4)	(280.0)	(350.2)	(559.0)
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	0.0	0.0	(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	0.0	0.0	(0.1)
Intersegment Eliminations | NGL Pipeline
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	(6.8)	(5.2)	(17.7)	(5.2)
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	(70.1)	(205.6)	(182.9)	(331.2)
Intersegment Eliminations | Crude Oil Product Sales
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	(15.0)	(9.8)	(57.7)	(33.9)
Intersegment Eliminations | NGL Product Sales
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	(31.3)	(58.9)	(91.3)	(187.9)
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)	(0.5)	(0.4)	(0.5)
Operating Segments | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total revenues	333.7	414.8	948.1	1,208.4
Operating Segments | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total revenues	175.5	315.2	492.5	381.2
Operating Segments | Storage and Logistics
Disaggregation of Revenue [Line Items]
Total revenues	753.6	1,116.0	2,333.3	3,567.2
Operating Segments | Natural Gas Gathering | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	32.2	33.4	95.5	92.2
Operating Segments | Natural Gas Gathering | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	4.8	10.1	13.6	57.0
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	16.9	14.7	46.3	43.6
Operating Segments | Crude Oil Gathering | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	1.9	1.7	6.0	4.6
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	51.0	41.8	139.9	117.7
Operating Segments | Water Gathering | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	8.4	7.5	25.2	13.0
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	20.0	20.7	56.6	54.8
Operating Segments | Natural Gas Processing | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	6.9	4.8	19.6	7.1
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		4.7		11.3
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	0.6	0.6	1.7	1.7
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	0.0	0.1	0.1	0.4
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	2.2	6.4	6.9
Operating Segments | Crude Oil Pipeline | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	1.4	1.5	3.7	4.2
Operating Segments | Crude Oil Pipeline | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.1	0.1	0.4	0.5
Operating Segments | Crude Oil Pipeline | Storage and Logistics
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.6	0.6	1.5	1.5
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	6.8	5.2	17.7	5.2
Operating Segments | NGL Pipeline | Storage and Logistics
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.2	0.1	0.3	0.2
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	2.2	5.0	12.4	16.3
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		0.6	0.4
Operating Segments | Natural Gas Product Sales | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	27.4	109.6	95.1	269.1
Operating Segments | Natural Gas Product Sales | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	47.5	144.4	113.6	145.3
Operating Segments | Natural Gas Product Sales | Storage and Logistics
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	78.2	248.4	211.9	508.0
Operating Segments | Crude Oil Product Sales | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	139.4	120.9	377.2	394.9
Operating Segments | Crude Oil Product Sales | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	0.8	0.0	1.1	0.0
Operating Segments | Crude Oil Product Sales | Storage and Logistics
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	352.2	362.8	954.4	1,130.3
Operating Segments | NGL Product Sales | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	42.8	68.3	126.5	222.7
Operating Segments | NGL Product Sales | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	98.8	136.2	296.9	136.2
Operating Segments | NGL Product Sales | Storage and Logistics
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	268.4	411.7	907.8	1,505.6
Operating Segments | Water Product Sales | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	1.0	2.1	2.9	5.0
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	0.5	0.8	1.1	1.4
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	0.1	0.2	1.0	0.5
Revenue from Contract with Customer
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	1,090.0	1,480.2	3,186.8	4,198.6
Revenue from Contract with Customer | Intersegment Eliminations
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	(123.4)	(280.0)	(350.2)	(559.0)
Revenue from Contract with Customer | Operating Segments | Gathering and Processing North
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	333.2	414.4	946.5	1,207.3
Revenue from Contract with Customer | Operating Segments | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	176.0	314.7	494.1	380.2
Revenue from Contract with Customer | Operating Segments | Storage and Logistics
Disaggregation of Revenue [Line Items]
Total Topic 606 revenues	704.2	1,031.1	2,096.4	3,170.1
Product and Service, Other
Disaggregation of Revenue [Line Items]
Non-Topic 606 revenues	49.4	85.8	236.9	399.2
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	0.5	0.4	1.6	1.1
Product and Service, Other | Operating Segments | Gathering and Processing South
Disaggregation of Revenue [Line Items]
Non-Topic 606 revenues	(0.5)	0.5	(1.6)	1.0
Product and Service, Other | Operating Segments | Storage and Logistics
Disaggregation of Revenue [Line Items]
Non-Topic 606 revenues	$ 49.4	$ 84.9	$ 236.9	$ 397.1