Employee Incentive Plans (Intrinsic and Fair Value of Units Vested) (Details) - Restricted Stock Units (RSUs) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
ENLK Restricted Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value of units vested	$ 0.1	$ 0.4	$ 3.8	$ 7.2
Fair value of units vested	0.0	0.5	9.0	7.5
ENLC Restricted Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value of units vested	0.0	0.6	3.8	8.9
Fair value of units vested	$ 0.0	$ 0.6	$ 11.8	$ 9.2