Equity-Based Awards, Unit Option Awards (Details) - Unit Option Awards [Member] - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Summary of awards activity, options [Roll Forward]
Beginning of period (in units)		1,270,000
Exercised (in units)		(1,270,000)
End of period (in units)		0
Options outstanding, weighted-average strike price [Roll Forward]
Weighted average strike price, beginning of period (in dollars per unit)		$ 16.14
Weighted average strike price, exercised (in dollars per unit)		16.14
Weighted average strike price, end of period (in dollars per unit)		$ 0
Total intrinsic value of unit option awards exercised during period		$ 21.7
Cash received from EPCO in connection with the exercise of unit option awards		13.1
Unit option award-related cash reimbursements to EPCO		$ 21.7