Goodwill and Intangible Assets - Schedule of Goodwill (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019 USD ($)
Goodwill [Roll Forward]
Goodwill, beginning of period	$ 1,310.2
Goodwill allocation	0.0
Impairment	(186.5)
Goodwill, end of period	1,123.7
Operating Segments | Permian
Goodwill [Roll Forward]
Goodwill, beginning of period	0.0
Goodwill allocation	184.6
Impairment	0.0
Goodwill, end of period	184.6
Operating Segments | North Texas
Goodwill [Roll Forward]
Goodwill, beginning of period	0.0
Goodwill allocation	125.7
Impairment	0.0
Goodwill, end of period	125.7
Operating Segments | Oklahoma
Goodwill [Roll Forward]
Goodwill, beginning of period	190.3
Goodwill allocation	623.1
Impairment	0.0
Goodwill, end of period	813.4
Operating Segments | Louisiana
Goodwill [Roll Forward]
Goodwill, beginning of period	0.0
Goodwill allocation	186.5
Impairment	(186.5)
Goodwill, end of period	0.0
Corporate
Goodwill [Roll Forward]
Goodwill, beginning of period	1,119.9
Goodwill allocation	(1,119.9)
Impairment	0.0
Goodwill, end of period	$ 0.0