Segment Information - Financial Information and Assets (Details) - USD ($) $ in Millions		3 Months Ended												12 Months Ended
		Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Revenue from contracts with customers														$ 6,038.5	$ 7,693.8
Cost of sales	[1]													(4,392.5)	(6,008.0)	$ (4,361.5)
Operating expenses														(467.1)	(453.4)	(418.7)
Gain (loss) on derivative activity														14.4	5.2	(4.2)
Segment profit (loss)														1,193.3	1,237.6	959.4
Depreciation and amortization														(617.0)	(577.3)	(545.3)
Impairments		$ (947.0)	$ 0.0	$ 0.0	$ (186.5)	$ (341.2)	$ (24.6)	$ 0.0	$ 0.0	$ (8.3)	$ (1.8)	$ 0.0	$ (7.0)	(1,133.5)	(365.8)	(17.1)
Goodwill		184.6				1,310.2				1,542.2				184.6	1,310.2	1,542.2
Capital expenditures														748.4	849.9	768.1
Corporate
Segment Reporting Information [Line Items]
Revenue from contracts with customers														(908.8)	(1,108.8)
Cost of sales														908.8	1,108.8	855.4
Operating expenses														0.0	0.0	0.0
Gain (loss) on derivative activity														14.4	5.2	(4.2)
Segment profit (loss)														14.4	5.2	(4.2)
Depreciation and amortization														(8.4)	(8.7)	(10.4)
Impairments														0.0	0.0	0.0
Goodwill		0.0				1,119.9				1,119.9				0.0	1,119.9	1,119.9
Capital expenditures														6.9	5.3	26.4
Permian | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														2,542.3	3,030.3
Cost of sales														(2,283.9)	(2,808.3)	(1,628.5)
Operating expenses														(112.9)	(96.1)	(85.1)
Gain (loss) on derivative activity														0.0	0.0	0.0
Segment profit (loss)														145.5	125.9	83.6
Depreciation and amortization														(119.8)	(111.0)	(109.9)
Impairments														(3.5)	(138.5)	0.0
Goodwill		184.6				0.0				29.3				184.6	0.0	29.3
Capital expenditures														364.5	271.7	186.1
North Texas | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														601.1	684.1
Cost of sales														(208.8)	(199.2)	(264.5)
Operating expenses														(102.9)	(112.7)	(121.8)
Gain (loss) on derivative activity														0.0	0.0	0.0
Segment profit (loss)														289.4	372.2	358.7
Depreciation and amortization														(139.8)	(127.9)	(127.0)
Impairments														(127.8)	(202.7)	0.0
Goodwill		0.0				0.0				202.7				0.0	0.0	202.7
Capital expenditures														39.0	24.7	18.2
Oklahoma | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														1,181.1	1,299.8
Cost of sales														(627.0)	(743.6)	(523.0)
Operating expenses														(104.0)	(90.3)	(64.6)
Gain (loss) on derivative activity														0.0	0.0	0.0
Segment profit (loss)														450.1	465.9	287.2
Depreciation and amortization														(194.9)	(178.8)	(156.3)
Impairments														(813.5)	0.0	0.0
Goodwill		0.0				190.3				190.3				0.0	190.3	190.3
Capital expenditures														238.1	493.8	450.1
Louisiana | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														2,622.8	3,788.4
Cost of sales														(2,181.6)	(3,365.7)	(2,800.9)
Operating expenses														(147.3)	(154.3)	(147.2)
Gain (loss) on derivative activity														0.0	0.0	0.0
Segment profit (loss)														293.9	268.4	234.1
Depreciation and amortization														(154.1)	(150.9)	(141.7)
Impairments														(188.7)	(24.6)	(17.1)
Goodwill		$ 0.0				$ 0.0				$ 0.0				0.0	0.0	0.0
Capital expenditures														99.9	54.4	87.3
Product sales
Segment Reporting Information [Line Items]
Revenue from contracts with customers														5,030.1	6,512.3	4,358.4
Product sales | Corporate
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	0.0	0.0
Product sales | Permian | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														2,070.2	2,496.9	1,344.0
Product sales | North Texas | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														160.2	170.1	162.5
Product sales | Oklahoma | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														365.6	300.8	128.8
Product sales | Louisiana | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														2,434.1	3,544.5	2,723.1
Natural gas sales
Segment Reporting Information [Line Items]
Revenue from contracts with customers														876.6	1,013.7
Natural gas sales | Corporate
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	0.0
Natural gas sales | Permian | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														94.3	152.3
Natural gas sales | North Texas | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														129.3	140.6
Natural gas sales | Oklahoma | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														236.4	189.7
Natural gas sales | Louisiana | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														416.6	531.1
NGL sales
Segment Reporting Information [Line Items]
Revenue from contracts with customers														1,777.0	2,841.0
NGL sales | Corporate
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	0.0
NGL sales | Permian | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.9	0.5
NGL sales | North Texas | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														30.9	29.0
NGL sales | Oklahoma | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														19.6	25.2
NGL sales | Louisiana | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														1,725.6	2,786.3
Crude oil and condensate sales
Segment Reporting Information [Line Items]
Revenue from contracts with customers														2,376.5	2,657.6
Crude oil and condensate sales | Corporate
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	0.0
Crude oil and condensate sales | Permian | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														1,975.0	2,344.1
Crude oil and condensate sales | North Texas | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	0.5
Crude oil and condensate sales | Oklahoma | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														109.6	85.9
Crude oil and condensate sales | Louisiana | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														291.9	227.1
Product sales—related parties
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	41.0	144.9
Product sales—related parties | Corporate
Segment Reporting Information [Line Items]
Revenue from contracts with customers														(910.4)	(1,105.5)	(721.8)
Product sales—related parties | Permian | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														361.6	453.8	357.0
Product sales—related parties | North Texas | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														100.3	51.2	120.5
Product sales—related parties | Oklahoma | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														421.1	593.6	349.4
Product sales—related parties | Louisiana | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														27.4	47.9	39.8
Product sales
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	2.5
Product sales | Corporate
Segment Reporting Information [Line Items]
Revenue from contracts with customers														(0.4)	0.0
Product sales | Permian | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.4	(0.3)
Product sales | North Texas | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	0.0
Product sales | Oklahoma | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	2.5
Product sales | Louisiana | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	0.3
NGL sales—related parties
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	37.4
NGL sales—related parties | Corporate
Segment Reporting Information [Line Items]
Revenue from contracts with customers														(889.3)	(1,104.3)
NGL sales—related parties | Permian | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														347.7	454.1
NGL sales—related parties | North Texas | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														94.8	49.4
NGL sales—related parties | Oklahoma | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														421.1	590.8
NGL sales—related parties | Louisiana | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														25.7	47.4
Crude oil and condensate sales—related parties
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	1.1
Crude oil and condensate sales—related parties | Corporate
Segment Reporting Information [Line Items]
Revenue from contracts with customers														(20.7)	(1.2)
Crude oil and condensate sales—related parties | Permian | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														13.5	0.0
Crude oil and condensate sales—related parties | North Texas | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														5.5	1.8
Crude oil and condensate sales—related parties | Oklahoma | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	0.3
Crude oil and condensate sales—related parties | Louisiana | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														1.7	0.2
Midstream services
Segment Reporting Information [Line Items]
Revenue from contracts with customers														1,008.4	763.3	552.3
Midstream services | Corporate
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	0.0	0.0
Midstream services | Permian | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														110.5	64.7	77.5
Midstream services | North Texas | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														340.6	231.1	51.6
Midstream services | Oklahoma | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														392.6	274.8	155.0
Midstream services | Louisiana | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														164.7	192.7	268.2
Gathering and transportation
Segment Reporting Information [Line Items]
Revenue from contracts with customers														538.0	386.3
Gathering and transportation | Corporate
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	0.0
Gathering and transportation | Permian | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														48.8	28.0
Gathering and transportation | North Texas | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														196.4	146.3
Gathering and transportation | Oklahoma | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														234.5	143.2
Gathering and transportation | Louisiana | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														58.3	68.8
Processing
Segment Reporting Information [Line Items]
Revenue from contracts with customers														314.9	239.7
Processing | Corporate
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	0.0
Processing | Permian | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														30.5	23.8
Processing | North Texas | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														143.0	83.9
Processing | Oklahoma | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														138.2	128.7
Processing | Louisiana | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														3.2	3.3
NGL services
Segment Reporting Information [Line Items]
Revenue from contracts with customers														50.7	59.6
NGL services | Corporate
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	0.0
NGL services | Permian | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	0.0
NGL services | North Texas | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.1	0.0
NGL services | Oklahoma | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	0.0
NGL services | Louisiana | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														50.6	59.6
Crude services
Segment Reporting Information [Line Items]
Revenue from contracts with customers														90.9	67.1
Crude services | Corporate
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	0.0
Crude services | Permian | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														19.2	4.2
Crude services | North Texas | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	0.0
Crude services | Oklahoma | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														19.8	2.8
Crude services | Louisiana | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														51.9	60.1
Other services
Segment Reporting Information [Line Items]
Revenue from contracts with customers														13.9	10.6
Other services | Corporate
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	0.0
Other services | Permian | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														12.0	8.7
Other services | North Texas | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														1.1	0.9
Other services | Oklahoma | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.1	0.1
Other services | Louisiana | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.7	0.9
Midstream services—related parties
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	377.2	688.2
Midstream services—related parties | Corporate
Segment Reporting Information [Line Items]
Revenue from contracts with customers														1.6	(3.3)	(133.6)
Midstream services—related parties | Permian | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	14.9	18.7
Midstream services—related parties | North Texas | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	231.7	410.4
Midstream services—related parties | Oklahoma | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														1.8	130.6	241.6
Midstream services—related parties | Louisiana | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														(3.4)	3.3	$ 151.1
Gathering and transportation—related parties
Segment Reporting Information [Line Items]
Revenue from contracts with customers															203.3
Gathering and transportation—related parties | Corporate
Segment Reporting Information [Line Items]
Revenue from contracts with customers															0.0
Gathering and transportation—related parties | Permian | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers															0.0
Gathering and transportation—related parties | North Texas | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers															122.7
Gathering and transportation—related parties | Oklahoma | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers															80.6
Gathering and transportation—related parties | Louisiana | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers															0.0
Processing—related parties
Segment Reporting Information [Line Items]
Revenue from contracts with customers															157.0
Processing—related parties | Corporate
Segment Reporting Information [Line Items]
Revenue from contracts with customers															0.0
Processing—related parties | Permian | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers															0.0
Processing—related parties | North Texas | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers															108.5
Processing—related parties | Oklahoma | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers															48.5
NGL services—related parties
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	0.0
NGL services—related parties | Corporate
Segment Reporting Information [Line Items]
Revenue from contracts with customers														3.4	(3.3)
NGL services—related parties | Permian | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	0.0
NGL services—related parties | North Texas | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	0.0
NGL services—related parties | Oklahoma | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	0.0
NGL services—related parties | Louisiana | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														(3.4)	3.3
Crude services—related parties
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	16.4
Crude services—related parties | Corporate
Segment Reporting Information [Line Items]
Revenue from contracts with customers														(1.8)	0.0
Crude services—related parties | Permian | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	14.9
Crude services—related parties | North Texas | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														0.0	0.0
Crude services—related parties | Oklahoma | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														1.8	1.5
Crude services—related parties | Louisiana | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers														$ 0.0	0.0
Other services—related parties
Segment Reporting Information [Line Items]
Revenue from contracts with customers															0.5
Other services—related parties | Corporate
Segment Reporting Information [Line Items]
Revenue from contracts with customers															0.0
Other services—related parties | Permian | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers															0.0
Other services—related parties | North Texas | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers															0.5
Other services—related parties | Oklahoma | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers															0.0
Other services—related parties | Louisiana | Operating Segments
Segment Reporting Information [Line Items]
Revenue from contracts with customers															$ 0.0

[1] Includes related party cost of sales of $21.7 million, $114.1 million, and $211.0 million for the years ended December 31, 2019, 2018, and 2017, respectively.