Goodwill and Intangible Assets (Intangibles) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Acquired Finite-Lived Intangible Assets
Accumulated amortization, beginning of period	$ (54.6)
Amortization expense			$ (36.5)
Accumulated amortization, end of period	$ (171.6)	$ (54.6)
Minimum
Acquired Finite-Lived Intangible Assets
Finite-Lived Intangible Asset, Useful Life	10 years
Maximum
Acquired Finite-Lived Intangible Assets
Finite-Lived Intangible Asset, Useful Life	20 years
Weighted Average
Acquired Finite-Lived Intangible Assets
Finite-Lived Intangible Asset, Useful Life	13 years 8 months 12 days
EnLink Midstream Partners, LP
Acquired Finite-Lived Intangible Assets
Customer relationships, beginning of period	$ 744.5	569.5
Acquisitions	1,051.3	436.0
Impairment, gross		(261.0)
Customer relationships, end of period	1,795.8	744.5	569.5
Accumulated amortization, beginning of period	(54.6)	(36.5)
Amortization expense	(117.0)	(56.0)
Impairment, accumulated amortization		37.9
Accumulated amortization, end of period	(171.6)	(54.6)	(36.5)
Impairment, net		(223.1)
Net carrying amount	$ 1,624.2	$ 689.9	$ 533.0