Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended												12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 1,756.2	$ 1,397.9	$ 1,263.6	$ 1,321.9	$ 1,224.9	$ 1,104.6	$ 1,033.2	$ 889.7	$ 1,066.5	$ 1,170.6	$ 1,274.5	$ 940.5	$ 5,739.6	$ 4,252.4	$ 4,452.1
Impairments	8.3	1.8	0.0	7.0	0.0	0.0	0.0	873.3	764.2	799.2	0.0	0.0	17.1	873.3	1,563.4
Operating income	96.9	72.1	68.9	56.5	39.2	65.9	45.2	(824.8)	(692.0)	(731.8)	71.4	50.5	294.4	(674.5)	(1,301.9)
Net income (loss) attributable to non-controlling interest	56.9	17.9	21.2	11.2	(25.3)	10.4	0.4	(413.7)	(528.4)	(562.5)	28.4	8.0	107.2	(428.2)	(1,054.5)
Net income (loss) attributable to EnLink Midstream, LLC	$ 202.6	$ 6.2	$ 5.9	$ (1.9)	$ (3.9)	$ 0.7	$ 0.8	$ (457.6)	$ (195.0)	$ (193.4)	$ 16.2	$ 17.0	$ 212.8	$ (460.0)	$ (355.2)
Net income (loss) attributable to EnLink Midstream, LLC per unit:
Basic common unit (in dollars per share)	$ 1.12	$ 0.03	$ 0.03	$ (0.01)	$ (0.02)	$ 0.00	$ 0.01	$ (2.56)	$ (1.18)	$ (1.18)	$ 0.09	$ 0.10	$ 1.18	$ (2.56)	$ (2.17)
Diluted common unit (in dollars per share)	$ 1.11	$ 0.03	$ 0.03	$ (0.01)	$ (0.02)	$ 0.00	$ 0.01	$ (2.56)	$ (1.18)	$ (1.18)	$ 0.09	$ 0.10	$ 1.17	$ (2.56)	$ (2.17)