Goodwill and Intangible Assets - Changes in Carrying Value of Goodwill (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Goodwill [Roll Forward]
Balance, beginning of period	$ 1,310,200,000		$ 184,600,000	$ 1,310,200,000	$ 1,542,200,000
Goodwill allocation				0
Impairment			(184,600,000)	(1,125,600,000)	(232,000,000.0)
Balance, end of period		$ 1,310,200,000	0	184,600,000	1,310,200,000
Operating Segments | Permian
Goodwill [Roll Forward]
Impairment		(29,300,000)
Operating Segments | North Texas
Goodwill [Roll Forward]
Impairment		(202,700,000)
EnLink Midstream Partners, LP | Operating Segments | Permian
Goodwill [Roll Forward]
Balance, beginning of period	0		184,600,000	0	29,300,000
Goodwill allocation				184,600,000
Impairment			(184,600,000)	0	(29,300,000)
Balance, end of period		0	0	184,600,000	0
EnLink Midstream Partners, LP | Operating Segments | Louisiana
Goodwill [Roll Forward]
Balance, beginning of period	0		0	0	0
Goodwill allocation				186,500,000
Impairment			0	(186,500,000)	0
Balance, end of period		0	0	0	0
EnLink Midstream Partners, LP | Operating Segments | Oklahoma
Goodwill [Roll Forward]
Balance, beginning of period	190,300,000		0	190,300,000	190,300,000
Goodwill allocation				623,100,000
Impairment			0	(813,400,000)	0
Balance, end of period		190,300,000	0	0	190,300,000
EnLink Midstream Partners, LP | Operating Segments | North Texas
Goodwill [Roll Forward]
Balance, beginning of period	0		0	0	202,700,000
Goodwill allocation				125,700,000
Impairment			0	(125,700,000)	(202,700,000)
Balance, end of period		0	0	0	0
EnLink Midstream Partners, LP | Corporate
Goodwill [Roll Forward]
Balance, beginning of period	1,119,900,000		0	1,119,900,000	1,119,900,000
Goodwill allocation				(1,119,900,000)
Impairment			0	0	0
Balance, end of period		$ 1,119,900,000	$ 0	$ 0	$ 1,119,900,000
EnLink Midstream Partners, LP | Corporate | Louisiana
Goodwill [Roll Forward]
Impairment	$ (186,500,000)